SERVER-50529 Add sort spec to grammar

author: Ted Tuckman <ted.tuckman@mongodb.com> 2020-08-31 13:14:03 -0400
committer: Evergreen Agent <no-reply@evergreen.mongodb.com> 2020-09-03 18:08:41 +0000
commit: 8e3271aaf22106853bf36429cfcee39ed6055f35 (patch)
tree: a2c1648af5ba4e905ca9b8d50f8a1055fd9576a5
parent: c4aa65bbd510369498ef7202596775c7824c87ce (diff)
download: mongo-8e3271aaf22106853bf36429cfcee39ed6055f35.tar.gz
15 files changed, 4909 insertions, 3407 deletions
diff --git a/src/mongo/db/cst/SConscript b/src/mongo/db/cst/SConscript
index 2aae8cfe8f3..1f17c8ddc06 100644
--- a/src/mongo/db/cst/SConscript
+++ b/src/mongo/db/cst/SConscript
@@ -15,6 +15,7 @@ env.Library(
         'c_node_validation.cpp',
         'c_node_disambiguation.cpp',
         'pipeline_parser_gen.cpp',
+        'cst_sort_translation.cpp',
     ],
     LIBDEPS=[
         "$BUILD_DIR/mongo/base",
diff --git a/src/mongo/db/cst/bson_lexer.cpp b/src/mongo/db/cst/bson_lexer.cpp
index df71bda546e..5fccfac805f 100644
--- a/src/mongo/db/cst/bson_lexer.cpp
+++ b/src/mongo/db/cst/bson_lexer.cpp
@@ -104,6 +104,7 @@ const StringMap<PipelineParserGen::token_type> reservedKeyLookup = {
     {"$indexOfBytes", PipelineParserGen::token::INDEX_OF_BYTES},
     {"$indexOfCP", PipelineParserGen::token::INDEX_OF_CP},
     {"$ltrim", PipelineParserGen::token::LTRIM},
+    {"$meta", PipelineParserGen::token::META},
     {"$regexFind", PipelineParserGen::token::REGEX_FIND},
     {"$regexFindAll", PipelineParserGen::token::REGEX_FIND_ALL},
     {"$regexMatch", PipelineParserGen::token::REGEX_MATCH},
@@ -130,6 +131,13 @@ const StringMap<PipelineParserGen::token_type> reservedKeyLookup = {
     {"find", PipelineParserGen::token::ARG_FIND},
     {"replacement", PipelineParserGen::token::ARG_REPLACEMENT},
 };
+// Mapping of reserved keywords to BSON tokens. Any key which is not included in this map is
+// assumed to be a user value.
+const StringMap<PipelineParserGen::token_type> reservedKeyValueLookup = {
+    {"randVal", PipelineParserGen::token::RAND_VAL},
+    {"textScore", PipelineParserGen::token::TEXT_SCORE},
+};
+
 bool isCompound(PipelineParserGen::symbol_type token) {
     return token.type_get() == static_cast<int>(PipelineParserGen::token::START_OBJECT) ||
         token.type_get() == static_cast<int>(PipelineParserGen::token::START_ARRAY);
@@ -246,11 +254,18 @@ void BSONLexer::tokenize(BSONElement elem, bool includeFieldName) {
         case NumberDouble:
             if (elem.numberDouble() == 0.0)
                 pushToken(elem, PipelineParserGen::token::DOUBLE_ZERO);
+            else if (elem.numberDouble() == 1.0)
+                pushToken(elem, PipelineParserGen::token::DOUBLE_ONE);
+            else if (elem.numberDouble() == -1.0)
+                pushToken(elem, PipelineParserGen::token::DOUBLE_NEGATIVE_ONE);
             else
-                pushToken(elem, PipelineParserGen::token::DOUBLE_NON_ZERO, elem.numberDouble());
+                pushToken(elem, PipelineParserGen::token::DOUBLE_OTHER, elem.numberDouble());
             break;
         case BSONType::String:
-            if (elem.valueStringData()[0] == '$') {
+            if (auto it = reservedKeyValueLookup.find(elem.valueStringData());
+                it != reservedKeyValueLookup.end()) {
+                pushToken(elem.String(), it->second);
+            } else if (elem.valueStringData()[0] == '$') {
                 if (elem.valueStringData()[1] == '$') {
                     pushToken(elem.valueStringData(),
                               PipelineParserGen::token::DOLLAR_DOLLAR_STRING,
@@ -314,8 +329,12 @@ void BSONLexer::tokenize(BSONElement elem, bool includeFieldName) {
         case NumberInt:
             if (elem.numberInt() == 0)
                 pushToken(elem, PipelineParserGen::token::INT_ZERO);
+            else if (elem.numberInt() == 1)
+                pushToken(elem, PipelineParserGen::token::INT_ONE);
+            else if (elem.numberInt() == -1)
+                pushToken(elem, PipelineParserGen::token::INT_NEGATIVE_ONE);
             else
-                pushToken(elem, PipelineParserGen::token::INT_NON_ZERO, elem.numberInt());
+                pushToken(elem, PipelineParserGen::token::INT_OTHER, elem.numberInt());
             break;
         case BSONType::bsonTimestamp:
             pushToken(elem, PipelineParserGen::token::TIMESTAMP, elem.timestamp());
@@ -323,14 +342,22 @@ void BSONLexer::tokenize(BSONElement elem, bool includeFieldName) {
         case NumberLong:
             if (elem.numberLong() == 0ll)
                 pushToken(elem, PipelineParserGen::token::LONG_ZERO);
+            else if (elem.numberLong() == 1ll)
+                pushToken(elem, PipelineParserGen::token::LONG_ONE);
+            else if (elem.numberLong() == -1ll)
+                pushToken(elem, PipelineParserGen::token::LONG_NEGATIVE_ONE);
             else
-                pushToken(elem, PipelineParserGen::token::LONG_NON_ZERO, elem.numberLong());
+                pushToken(elem, PipelineParserGen::token::LONG_OTHER, elem.numberLong());
             break;
         case NumberDecimal:
             if (elem.numberDecimal() == Decimal128::kNormalizedZero)
                 pushToken(elem, PipelineParserGen::token::DECIMAL_ZERO);
-            else
-                pushToken(elem, PipelineParserGen::token::DECIMAL_NON_ZERO, elem.numberDecimal());
+            else if (elem.numberDecimal() == Decimal128(1)) {
+                pushToken(elem, PipelineParserGen::token::DECIMAL_ONE);
+            } else if (elem.numberDecimal() == Decimal128(-1)) {
+                pushToken(elem, PipelineParserGen::token::DECIMAL_NEGATIVE_ONE);
+            } else
+                pushToken(elem, PipelineParserGen::token::DECIMAL_OTHER, elem.numberDecimal());
             break;
         case BSONType::MinKey:
             pushToken(elem, PipelineParserGen::token::MIN_KEY, UserMinKey{});
diff --git a/src/mongo/db/cst/bson_lexer_test.cpp b/src/mongo/db/cst/bson_lexer_test.cpp
index 039b5dcc911..459c16a64e4 100644
--- a/src/mongo/db/cst/bson_lexer_test.cpp
+++ b/src/mongo/db/cst/bson_lexer_test.cpp
@@ -49,14 +49,14 @@ void assertTokensMatch(BSONLexer& lexer,
 }
 
 TEST(BSONLexerTest, TokenizesOpaqueUserObjects) {
-    auto input = fromjson("{pipeline: [{a: 1, b: '1', c: \"$path\", d: \"$$NOW\"}]}");
+    auto input = fromjson("{pipeline: [{a: 2, b: '1', c: \"$path\", d: \"$$NOW\"}]}");
     BSONLexer lexer(input["pipeline"].Array(), PipelineParserGen::token::START_PIPELINE);
     assertTokensMatch(lexer,
                       {PipelineParserGen::token::START_PIPELINE,
                        PipelineParserGen::token::START_ARRAY,
                        PipelineParserGen::token::START_OBJECT,
                        PipelineParserGen::token::FIELDNAME,
-                       PipelineParserGen::token::INT_NON_ZERO,
+                       PipelineParserGen::token::INT_OTHER,
                        PipelineParserGen::token::FIELDNAME,
                        PipelineParserGen::token::STRING,
                        PipelineParserGen::token::FIELDNAME,
@@ -99,7 +99,7 @@ TEST(BSONLexerTest, TokenizesReservedKeywordsAtAnyDepth) {
 }
 
 TEST(BSONLexerTest, MidRuleActionToSortNestedObject) {
-    auto input = fromjson("{pipeline: [{pipeline: 1.0, coll: 'test'}]}");
+    auto input = fromjson("{pipeline: [{pipeline: 2.0, coll: 'test'}]}");
     BSONLexer lexer(input["pipeline"].Array(), PipelineParserGen::token::START_PIPELINE);
     // Iterate until the first object.
     ASSERT_EQ(lexer.getNext().type_get(), PipelineParserGen::token::START_PIPELINE);
@@ -112,7 +112,7 @@ TEST(BSONLexerTest, MidRuleActionToSortNestedObject) {
                      PipelineParserGen::token::ARG_COLL,
                      PipelineParserGen::token::STRING,
                      PipelineParserGen::token::ARG_PIPELINE,
-                     PipelineParserGen::token::DOUBLE_NON_ZERO,
+                     PipelineParserGen::token::DOUBLE_OTHER,
                      PipelineParserGen::token::END_OBJECT,
                      PipelineParserGen::token::END_ARRAY};
     assertTokensMatch(lexer, expected);
@@ -121,7 +121,7 @@ TEST(BSONLexerTest, MidRuleActionToSortNestedObject) {
 
 TEST(BSONLexerTest, MidRuleActionToSortDoesNotSortNestedObjects) {
     auto input = fromjson(
-        "{pipeline: [{$unionWith: {pipeline: [{$unionWith: 'inner', a: 1.0}], coll: 'outer'}}]}");
+        "{pipeline: [{$unionWith: {pipeline: [{$unionWith: 'inner', a: 3.0}], coll: 'outer'}}]}");
     BSONLexer lexer(input["pipeline"].Array(), PipelineParserGen::token::START_PIPELINE);
     // Iterate until we reach the $unionWith object.
     ASSERT_EQ(lexer.getNext().type_get(), PipelineParserGen::token::START_PIPELINE);
@@ -140,7 +140,7 @@ TEST(BSONLexerTest, MidRuleActionToSortDoesNotSortNestedObjects) {
         PipelineParserGen::token::STAGE_UNION_WITH,
         PipelineParserGen::token::STRING,  // $unionWith: 'inner'
         PipelineParserGen::token::FIELDNAME,
-        PipelineParserGen::token::DOUBLE_NON_ZERO,  // a: 1.0
+        PipelineParserGen::token::DOUBLE_OTHER,  // a: 3.0
         PipelineParserGen::token::END_OBJECT,
         PipelineParserGen::token::END_ARRAY,
         PipelineParserGen::token::END_OBJECT,
@@ -152,7 +152,7 @@ TEST(BSONLexerTest, MidRuleActionToSortDoesNotSortNestedObjects) {
 
 TEST(BSONLexerTest, MultipleNestedObjectsAreReorderedCorrectly) {
     auto input = fromjson(
-        "{pipeline: [{$unionWith: {pipeline: [{$unionWith: 'inner', a: 1.0}], coll: [{$unionWith: "
+        "{pipeline: [{$unionWith: {pipeline: [{$unionWith: 'inner', a: 3.0}], coll: [{$unionWith: "
         "'innerB', a: 2.0}]}}]}");
     BSONLexer lexer(input["pipeline"].Array(), PipelineParserGen::token::START_PIPELINE);
     // Iterate until we reach the $unionWith object.
@@ -168,9 +168,9 @@ TEST(BSONLexerTest, MultipleNestedObjectsAreReorderedCorrectly) {
         PipelineParserGen::token::START_OBJECT,
         // The nested pipeline does *not* get sorted, meaning '$unionWith' stays before 'a'.
         PipelineParserGen::token::STAGE_UNION_WITH,
-        PipelineParserGen::token::STRING,           // innerb
-        PipelineParserGen::token::FIELDNAME,        // a
-        PipelineParserGen::token::DOUBLE_NON_ZERO,  // a: 2.0
+        PipelineParserGen::token::STRING,        // innerb
+        PipelineParserGen::token::FIELDNAME,     // a
+        PipelineParserGen::token::DOUBLE_OTHER,  // a: 2.0
         PipelineParserGen::token::END_OBJECT,
         PipelineParserGen::token::END_ARRAY,
         // Coll nested object ends here.
@@ -179,9 +179,9 @@ TEST(BSONLexerTest, MultipleNestedObjectsAreReorderedCorrectly) {
         PipelineParserGen::token::START_OBJECT,
         // The nested pipeline does *not* get sorted, meaning '$unionWith' stays before 'a'.
         PipelineParserGen::token::STAGE_UNION_WITH,
-        PipelineParserGen::token::STRING,           // $unionWith: 'inner'
-        PipelineParserGen::token::FIELDNAME,        // a
-        PipelineParserGen::token::DOUBLE_NON_ZERO,  // a: 1.0
+        PipelineParserGen::token::STRING,        // $unionWith: 'inner'
+        PipelineParserGen::token::FIELDNAME,     // a
+        PipelineParserGen::token::DOUBLE_OTHER,  // a: 3.0
         PipelineParserGen::token::END_OBJECT,
         PipelineParserGen::token::END_ARRAY,
         PipelineParserGen::token::END_OBJECT,
@@ -192,7 +192,7 @@ TEST(BSONLexerTest, MultipleNestedObjectsAreReorderedCorrectly) {
 }
 TEST(BSONLexerTest, MultiLevelBSONDoesntSortChildren) {
     auto input = fromjson(
-        "{pipeline: [{$unionWith: {pipeline: [{$unionWith: {'nested': 1.0, 'apple': 1.0}, a: 1.0}],"
+        "{pipeline: [{$unionWith: {pipeline: [{$unionWith: {'nested': 3.0, 'apple': 3.0}, a: 3.0}],"
         " coll: 'outer'}}]}");
     BSONLexer lexer(input["pipeline"].Array(), PipelineParserGen::token::START_PIPELINE);
     // Iterate until we reach the $unionWith object.
@@ -212,14 +212,14 @@ TEST(BSONLexerTest, MultiLevelBSONDoesntSortChildren) {
         PipelineParserGen::token::STAGE_UNION_WITH,
         // Second nested object
         PipelineParserGen::token::START_OBJECT,
-        PipelineParserGen::token::FIELDNAME,  // nested: 1.0
-        PipelineParserGen::token::DOUBLE_NON_ZERO,
-        PipelineParserGen::token::FIELDNAME,  // apple: 1.0
-        PipelineParserGen::token::DOUBLE_NON_ZERO,
+        PipelineParserGen::token::FIELDNAME,  // nested: 3.0
+        PipelineParserGen::token::DOUBLE_OTHER,
+        PipelineParserGen::token::FIELDNAME,  // apple: 3.0
+        PipelineParserGen::token::DOUBLE_OTHER,
         PipelineParserGen::token::END_OBJECT,
         // End second nested object
         PipelineParserGen::token::FIELDNAME,
-        PipelineParserGen::token::DOUBLE_NON_ZERO,  // a: 1.0
+        PipelineParserGen::token::DOUBLE_OTHER,  // a: 3.0
         PipelineParserGen::token::END_OBJECT,
         // End first nested object
         PipelineParserGen::token::END_ARRAY,
@@ -266,5 +266,25 @@ TEST(BSONLexerTest, TokenizesObjWithPathCorrectly) {
                       });
 }
 
+TEST(BSONLexerTest, SortSpecTokensGeneratedCorrectly) {
+    auto input = fromjson("{val: 1, test: -1.0, rand: {$meta: 'textScore'}}");
+    BSONLexer lexer(input, PipelineParserGen::token::START_SORT);
+    assertTokensMatch(lexer,
+                      {
+                          PipelineParserGen::token::START_SORT,
+                          PipelineParserGen::token::START_OBJECT,
+                          PipelineParserGen::token::FIELDNAME,
+                          PipelineParserGen::token::INT_ONE,
+                          PipelineParserGen::token::FIELDNAME,
+                          PipelineParserGen::token::DOUBLE_NEGATIVE_ONE,
+                          PipelineParserGen::token::FIELDNAME,
+                          PipelineParserGen::token::START_OBJECT,
+                          PipelineParserGen::token::META,
+                          PipelineParserGen::token::TEXT_SCORE,
+                          PipelineParserGen::token::END_OBJECT,
+                          PipelineParserGen::token::END_OBJECT,
+                      });
+}
+
 }  // namespace
 }  // namespace mongo
diff --git a/src/mongo/db/cst/cst_error_test.cpp b/src/mongo/db/cst/cst_error_test.cpp
index 15ebe4028f8..10a0cbdda2b 100755
--- a/src/mongo/db/cst/cst_error_test.cpp
+++ b/src/mongo/db/cst/cst_error_test.cpp
@@ -78,13 +78,13 @@ TEST(CstErrorTest, UnknownStageName) {
 
 TEST(CstErrorTest, InvalidStageArgument) {
     {
-        auto input = fromjson("{pipeline: [{$sample: 1}]}");
+        auto input = fromjson("{pipeline: [{$sample: 2}]}");
         BSONLexer lexer(input["pipeline"].Array(), PipelineParserGen::token::START_PIPELINE);
         ASSERT_THROWS_CODE_AND_WHAT(
             PipelineParserGen(lexer, nullptr).parse(),
             AssertionException,
             ErrorCodes::FailedToParse,
-            "syntax error, unexpected non-zero integer, expecting object at element '1' within "
+            "syntax error, unexpected arbitrary integer, expecting object at element '2' within "
             "'$sample' within array at index 0 of input pipeline");
     }
     {
@@ -200,5 +200,35 @@ TEST(CstErrorTest, DeeplyNestedSyntaxError) {
         "within array at index 0 of input pipeline");
 }
 
+TEST(CstErrorTest, SortWithRandomIntFails) {
+    auto input = fromjson("{val: 5}");
+    BSONLexer lexer(input, PipelineParserGen::token::START_SORT);
+    ASSERT_THROWS_CODE_AND_WHAT(
+        PipelineParserGen(lexer, nullptr).parse(),
+        AssertionException,
+        ErrorCodes::FailedToParse,
+        "syntax error, unexpected arbitrary integer at element '5' of input filter");
+}
+
+TEST(CstErrorTest, SortWithInvalidMetaFails) {
+    auto input = fromjson("{val: {$meta: \"str\"}}");
+    BSONLexer lexer(input, PipelineParserGen::token::START_SORT);
+    ASSERT_THROWS_CODE_AND_WHAT(PipelineParserGen(lexer, nullptr).parse(),
+                                AssertionException,
+                                ErrorCodes::FailedToParse,
+                                "syntax error, unexpected string, expecting randVal or textScore "
+                                "at element 'str' within '$meta' of input filter");
+}
+
+TEST(CstErrorTest, SortWithMetaSiblingKeyFails) {
+    auto input = fromjson("{val: {$meta: \"textScore\", someKey: 4}}");
+    BSONLexer lexer(input, PipelineParserGen::token::START_SORT);
+    ASSERT_THROWS_CODE_AND_WHAT(PipelineParserGen(lexer, nullptr).parse(),
+                                AssertionException,
+                                ErrorCodes::FailedToParse,
+                                "syntax error, unexpected fieldname, expecting end of object at "
+                                "element 'someKey' of input filter");
+}
+
 }  // namespace
 }  // namespace mongo
diff --git a/src/mongo/db/cst/cst_pipeline_translation_test.cpp b/src/mongo/db/cst/cst_pipeline_translation_test.cpp
index 429ec779b85..6859d8db7f3 100644
--- a/src/mongo/db/cst/cst_pipeline_translation_test.cpp
+++ b/src/mongo/db/cst/cst_pipeline_translation_test.cpp
@@ -36,6 +36,7 @@
 #include "mongo/bson/unordered_fields_bsonobj_comparator.h"
 #include "mongo/db/cst/c_node.h"
 #include "mongo/db/cst/cst_pipeline_translation.h"
+#include "mongo/db/cst/cst_sort_translation.h"
 #include "mongo/db/cst/key_fieldname.h"
 #include "mongo/db/cst/key_value.h"
 #include "mongo/db/exec/document_value/document.h"
@@ -47,6 +48,7 @@
 #include "mongo/db/pipeline/document_source_single_document_transformation.h"
 #include "mongo/db/pipeline/document_source_skip.h"
 #include "mongo/db/pipeline/expression_context_for_test.h"
+#include "mongo/db/query/sort_pattern.h"
 #include "mongo/unittest/unittest.h"
 
 namespace mongo {
@@ -58,6 +60,31 @@ auto getExpCtx() {
     return boost::intrusive_ptr<ExpressionContextForTest>{new ExpressionContextForTest(nss)};
 }
 
+void assertSortPatternsEQ(SortPattern correct, SortPattern fromTest) {
+    for (size_t i = 0; i < correct.size(); ++i) {
+        ASSERT_EQ(correct[i].isAscending, fromTest[i].isAscending);
+        if (correct[i].fieldPath) {
+            if (fromTest[i].fieldPath) {
+                ASSERT_EQ(correct[i].fieldPath->fullPath(), fromTest[i].fieldPath->fullPath());
+            } else {
+                FAIL("Pattern missing fieldpath");
+            }
+        } else if (fromTest[i].fieldPath) {
+            FAIL("Pattern incorrectly had fieldpath");
+        }
+        if (correct[i].expression) {
+            if (fromTest[i].expression)
+                ASSERT_EQ(correct[i].expression->serialize(false).toString(),
+                          fromTest[i].expression->serialize(false).toString());
+            else {
+                FAIL("Pattern missing expression");
+            }
+        } else if (fromTest[i].expression) {
+            FAIL("Pattern incorrectly had expression");
+        }
+    }
+}
+
 TEST(CstPipelineTranslationTest, TranslatesEmpty) {
     const auto cst = CNode{CNode::ArrayChildren{}};
     auto pipeline = cst_pipeline_translation::translatePipeline(cst, getExpCtx());
@@ -1231,5 +1258,60 @@ TEST(CstPipelineTranslationTest, InvalidDollarPrefixStringFails) {
     }
 }
 
+TEST(CstSortTranslationTest, BasicSortGeneratesCorrectSortPattern) {
+    const auto cst =
+        CNode{CNode::ObjectChildren{{UserFieldname{"val"}, CNode{KeyValue::intOneKey}}}};
+    auto expCtx = getExpCtx();
+    auto pattern = cst_sort_translation::translateSortSpec(cst, expCtx);
+    auto correctPattern = SortPattern(fromjson("{val: 1}"), expCtx);
+    assertSortPatternsEQ(correctPattern, pattern);
+}
+
+TEST(CstSortTranslationTest, MultiplePartSortGeneratesCorrectSortPattern) {
+    {
+        const auto cst =
+            CNode{CNode::ObjectChildren{{UserFieldname{"val"}, CNode{KeyValue::intOneKey}},
+                                        {UserFieldname{"test"}, CNode{KeyValue::intNegOneKey}}}};
+        auto expCtx = getExpCtx();
+        auto pattern = cst_sort_translation::translateSortSpec(cst, expCtx);
+        auto correctPattern = SortPattern(fromjson("{val: 1, test: -1}"), expCtx);
+        assertSortPatternsEQ(correctPattern, pattern);
+    }
+    {
+        const auto cst =
+            CNode{CNode::ObjectChildren{{UserFieldname{"val"}, CNode{KeyValue::doubleOneKey}},
+                                        {UserFieldname{"test"}, CNode{KeyValue::intNegOneKey}},
+                                        {UserFieldname{"third"}, CNode{KeyValue::longNegOneKey}}}};
+        auto expCtx = getExpCtx();
+        auto pattern = cst_sort_translation::translateSortSpec(cst, expCtx);
+        auto correctPattern = SortPattern(fromjson("{val: 1, test: -1, third: -1}"), expCtx);
+        assertSortPatternsEQ(correctPattern, pattern);
+    }
+}
+
+TEST(CstSortTranslationTest, SortWithMetaGeneratesCorrectSortPattern) {
+    {
+        const auto cst = CNode{CNode::ObjectChildren{
+            {UserFieldname{"val"},
+             CNode{
+                 CNode::ObjectChildren{{KeyFieldname::meta, CNode{KeyValue::randVal}}},
+             }}}};
+        auto expCtx = getExpCtx();
+        auto pattern = cst_sort_translation::translateSortSpec(cst, expCtx);
+        auto correctPattern = SortPattern(fromjson("{val: {$meta: \"randVal\"}}"), expCtx);
+        assertSortPatternsEQ(correctPattern, pattern);
+    }
+    {
+        const auto cst = CNode{CNode::ObjectChildren{
+            {UserFieldname{"val"},
+             CNode{
+                 CNode::ObjectChildren{{KeyFieldname::meta, CNode{KeyValue::textScore}}},
+             }}}};
+        auto expCtx = getExpCtx();
+        auto pattern = cst_sort_translation::translateSortSpec(cst, expCtx);
+        auto correctPattern = SortPattern(fromjson("{val: {$meta: \"textScore\"}}"), expCtx);
+        assertSortPatternsEQ(correctPattern, pattern);
+    }
+}
 }  // namespace
 }  // namespace mongo
diff --git a/src/mongo/db/cst/cst_sort_translation.cpp b/src/mongo/db/cst/cst_sort_translation.cpp
new file mode 100644
index 00000000000..e88b21477dc
--- /dev/null
+++ b/src/mongo/db/cst/cst_sort_translation.cpp
@@ -0,0 +1,107 @@
+/**
+ *    Copyright (C) 2020-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#include <set>
+#include <string>
+#include <vector>
+
+#include "mongo/db/cst/cst_sort_translation.h"
+#include "mongo/db/cst/key_value.h"
+#include "mongo/db/exec/document_value/document_metadata_fields.h"
+#include "mongo/db/pipeline/expression.h"
+#include "mongo/db/pipeline/field_path.h"
+#include "mongo/util/visit_helper.h"
+
+namespace mongo::cst_sort_translation {
+
+SortPattern translateSortSpec(const CNode& cst,
+                              const boost::intrusive_ptr<ExpressionContext>& expCtx) {
+    // Assume object children, only thing possible for sort.
+    const auto& children = cst.objectChildren();
+    std::vector<SortPattern::SortPatternPart> sortKeys;
+    std::set<std::string> paths;
+    for (const auto& keyValPair : children) {
+        const auto& path = stdx::get<UserString>(keyValPair.first);
+        paths.insert(path);
+        stdx::visit(
+            visit_helper::Overloaded{
+                [&](const CNode::ObjectChildren& object) {
+                    // $meta is always the only key in the object, and always has a KeyValue as its
+                    // value.
+                    // If sorting by textScore, put highest scores first. If $meta was specified
+                    // with randVal order doesn't matter, so always put descending.
+                    auto keyVal = stdx::get<KeyValue>(object[0].second.payload);
+                    switch (keyVal) {
+                        case KeyValue::randVal:
+                            sortKeys.push_back(SortPattern::SortPatternPart{
+                                false,
+                                boost::none,
+                                make_intrusive<ExpressionMeta>(expCtx.get(),
+                                                               DocumentMetadataFields::kRandVal)});
+                            break;
+                        case KeyValue::textScore:
+                            sortKeys.push_back(SortPattern::SortPatternPart{
+                                false,
+                                boost::none,
+                                make_intrusive<ExpressionMeta>(
+                                    expCtx.get(), DocumentMetadataFields::kTextScore)});
+                            break;
+                        default:
+                            MONGO_UNREACHABLE;
+                    }
+                },
+                [&](const KeyValue& keyValue) {
+                    switch (keyValue) {
+                        case KeyValue::intOneKey:
+                        case KeyValue::longOneKey:
+                        case KeyValue::doubleOneKey:
+                        case KeyValue::decimalOneKey:
+                            sortKeys.push_back(SortPattern::SortPatternPart{
+                                true, FieldPath{path}, nullptr /* meta */});
+
+                            break;
+                        case KeyValue::intNegOneKey:
+                        case KeyValue::longNegOneKey:
+                        case KeyValue::doubleNegOneKey:
+                        case KeyValue::decimalNegOneKey:
+                            sortKeys.push_back(SortPattern::SortPatternPart{
+                                false, FieldPath{path}, nullptr /* meta */});
+                            break;
+                        default:
+                            MONGO_UNREACHABLE;
+                    }
+                },
+                [](auto&&) { MONGO_UNREACHABLE; },
+            },
+            keyValPair.second.payload);
+    }
+    return SortPattern(std::move(sortKeys), std::move(paths));
+}
+
+}  // namespace mongo::cst_sort_translation
diff --git a/src/mongo/db/cst/cst_sort_translation.h b/src/mongo/db/cst/cst_sort_translation.h
new file mode 100644
index 00000000000..2a5f6210b50
--- /dev/null
+++ b/src/mongo/db/cst/cst_sort_translation.h
@@ -0,0 +1,44 @@
+/**
+ *    Copyright (C) 2020-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#pragma once
+
+#include "mongo/platform/basic.h"
+
+#include <memory>
+
+#include "mongo/db/cst/c_node.h"
+#include "mongo/db/query/sort_pattern.h"
+
+namespace mongo::cst_sort_translation {
+
+SortPattern translateSortSpec(const CNode& cst,
+                              const boost::intrusive_ptr<ExpressionContext>& expCtx);
+
+}  // namespace mongo::cst_sort_translation
diff --git a/src/mongo/db/cst/cst_test.cpp b/src/mongo/db/cst/cst_test.cpp
index 1fa155a72e9..18425a72fc5 100644
--- a/src/mongo/db/cst/cst_test.cpp
+++ b/src/mongo/db/cst/cst_test.cpp
@@ -244,10 +244,11 @@ TEST(CstGrammarTest, ParsesProject) {
         auto stages = stdx::get<CNode::ArrayChildren>(output.payload);
         ASSERT_EQ(1, stages.size());
         ASSERT(KeyFieldname::projectInclusion == stages[0].firstKeyFieldname());
-        ASSERT_EQ(stages[0].toBson().toString(),
-                  "{ projectInclusion: { a: \"<NonZeroKey of type double 1.000000>\", b: { "
-                  "<CompoundInclusionKey>: { c: \"<NonZeroKey of type int 1>\", d: \"<NonZeroKey "
-                  "of type decimal 1.0>\" } }, id: \"<NonZeroKey of type long 1>\" } }");
+        ASSERT_EQ(
+            stages[0].toBson().toString(),
+            "{ projectInclusion: { a: \"<NonZeroKey of type double 1.000000>\", b: { "
+            "<CompoundInclusionKey>: { c: \"<NonZeroKey of type int 1>\", d: \"<NonZeroKey "
+            "of type decimal 1.00000000000000>\" } }, id: \"<NonZeroKey of type long 1>\" } }");
     }
     {
         CNode output;
@@ -907,5 +908,24 @@ TEST(CstGrammarTest, FailsToParseDollarPrefixedPredicates) {
     }
 }
 
+TEST(CstGrammarTest, ParsesBasicSort) {
+    CNode output;
+    auto input = fromjson("{val: 1, test: -1}");
+    BSONLexer lexer(input, PipelineParserGen::token::START_SORT);
+    auto parseTree = PipelineParserGen(lexer, &output);
+    ASSERT_EQ(0, parseTree.parse());
+    ASSERT_EQ(output.toBson().toString(),
+              "{ val: \"<KeyValue intOneKey>\", test: \"<KeyValue intNegOneKey>\" }");
+}
+
+TEST(CstGrammarTest, ParsesMetaSort) {
+    CNode output;
+    auto input = fromjson("{val: {$meta: \"textScore\"}}");
+    BSONLexer lexer(input, PipelineParserGen::token::START_SORT);
+    auto parseTree = PipelineParserGen(lexer, &output);
+    ASSERT_EQ(0, parseTree.parse());
+    ASSERT_EQ(output.toBson().toString(), "{ val: { meta: \"<KeyValue textScore>\" } }");
+}
+
 }  // namespace
 }  // namespace mongo
diff --git a/src/mongo/db/cst/key_fieldname.h b/src/mongo/db/cst/key_fieldname.h
index 90d3fcbfe19..1c9b9b7f570 100644
--- a/src/mongo/db/cst/key_fieldname.h
+++ b/src/mongo/db/cst/key_fieldname.h
@@ -71,6 +71,7 @@
     ENUMIFY(lte)                 \
     ENUMIFY(ltrim)               \
     ENUMIFY(match)               \
+    ENUMIFY(meta)                \
     ENUMIFY(mod)                 \
     ENUMIFY(multiply)            \
     ENUMIFY(ne)                  \
@@ -88,8 +89,8 @@
     ENUMIFY(regexFindAll)        \
     ENUMIFY(regexMatch)          \
     ENUMIFY(replaceAll)          \
-    ENUMIFY(replacementArg)      \
     ENUMIFY(replaceOne)          \
+    ENUMIFY(replacementArg)      \
     ENUMIFY(round)               \
     ENUMIFY(rtrim)               \
     ENUMIFY(sample)              \
@@ -97,9 +98,9 @@
     ENUMIFY(skip)                \
     ENUMIFY(split)               \
     ENUMIFY(sqrt)                \
-    ENUMIFY(strcasecmp)          \
     ENUMIFY(strLenBytes)         \
     ENUMIFY(strLenCP)            \
+    ENUMIFY(strcasecmp)          \
     ENUMIFY(substr)              \
     ENUMIFY(substrBytes)         \
     ENUMIFY(substrCP)            \
diff --git a/src/mongo/db/cst/key_value.h b/src/mongo/db/cst/key_value.h
index f7c223f7135..35c4987f82b 100644
--- a/src/mongo/db/cst/key_value.h
+++ b/src/mongo/db/cst/key_value.h
@@ -33,14 +33,24 @@
 
 #include "mongo/util/printable_enum.h"
 
-#define KEYVALUES(ENUMIFY)  \
-    ENUMIFY(intZeroKey)     \
-    ENUMIFY(longZeroKey)    \
-    ENUMIFY(doubleZeroKey)  \
-    ENUMIFY(decimalZeroKey) \
-    ENUMIFY(trueKey)        \
-    ENUMIFY(falseKey)       \
-    ENUMIFY(absentKey)
+#define KEYVALUES(ENUMIFY)    \
+    ENUMIFY(intOneKey)        \
+    ENUMIFY(intNegOneKey)     \
+    ENUMIFY(intZeroKey)       \
+    ENUMIFY(longOneKey)       \
+    ENUMIFY(longNegOneKey)    \
+    ENUMIFY(longZeroKey)      \
+    ENUMIFY(doubleOneKey)     \
+    ENUMIFY(doubleNegOneKey)  \
+    ENUMIFY(doubleZeroKey)    \
+    ENUMIFY(decimalOneKey)    \
+    ENUMIFY(decimalNegOneKey) \
+    ENUMIFY(decimalZeroKey)   \
+    ENUMIFY(trueKey)          \
+    ENUMIFY(falseKey)         \
+    ENUMIFY(absentKey)        \
+    ENUMIFY(textScore)        \
+    ENUMIFY(randVal)
 
 MAKE_PRINTABLE_ENUM(KeyValue, KEYVALUES);
 MAKE_PRINTABLE_ENUM_STRING_ARRAY(key_value, KeyValue, KEYVALUES);
diff --git a/src/mongo/db/cst/pipeline_grammar.yy b/src/mongo/db/cst/pipeline_grammar.yy
index b08b1b7e7a3..fa9580fedcd 100644
--- a/src/mongo/db/cst/pipeline_grammar.yy
+++ b/src/mongo/db/cst/pipeline_grammar.yy
@@ -144,8 +144,12 @@
     CONVERT
     DATE_FROM_STRING
     DATE_TO_STRING
+    DECIMAL_NEGATIVE_ONE "-1 (decimal)"
+    DECIMAL_ONE "1 (decimal)"
     DECIMAL_ZERO "zero (decimal)"
     DIVIDE
+    DOUBLE_NEGATIVE_ONE "-1 (double)"
+    DOUBLE_ONE "1 (double)"
     DOUBLE_ZERO "zero (double)"
     END_ARRAY "end of array"
     END_OBJECT "end of object"
@@ -157,21 +161,27 @@
     ID
     INDEX_OF_BYTES
     INDEX_OF_CP
+    INT_NEGATIVE_ONE "-1 (int)"
+    INT_ONE "1 (int)"
     INT_ZERO "zero (int)"
     LITERAL
     LN
     LOG
     LOGTEN
+    LONG_NEGATIVE_ONE "-1 (long)"
+    LONG_ONE "1 (long)"
     LONG_ZERO "zero (long)"
     LT
     LTE
     LTRIM
+    META
     MOD
     MULTIPLY
     NE
     NOT
     OR
     POW
+    RAND_VAL "randVal"
     REGEX_FIND
     REGEX_FIND_ALL
     REGEX_MATCH
@@ -196,6 +206,7 @@
     SUBSTR_BYTES
     SUBSTR_CP
     SUBTRACT
+    TEXT_SCORE "textScore"
     TO_BOOL
     TO_DATE
     TO_DECIMAL
@@ -225,17 +236,17 @@
 %token <BSONCode> JAVASCRIPT "Code"
 %token <BSONSymbol> SYMBOL "Symbol"
 %token <BSONCodeWScope> JAVASCRIPT_W_SCOPE "CodeWScope"
-%token <int> INT_NON_ZERO "non-zero integer"
-%token <long long> LONG_NON_ZERO "non-zero long"
-%token <double> DOUBLE_NON_ZERO "non-zero double"
-%token <Decimal128> DECIMAL_NON_ZERO "non-zero decimal"
+%token <int> INT_OTHER "arbitrary integer"
+%token <long long> LONG_OTHER "arbitrary long"
+%token <double> DOUBLE_OTHER "arbitrary double"
+%token <Decimal128> DECIMAL_OTHER "arbitrary decimal"
 %token <Timestamp> TIMESTAMP "Timestamp"
 %token <UserMinKey> MIN_KEY "minKey"
 %token <UserMaxKey> MAX_KEY "maxKey"
 %token <std::string> DOLLAR_STRING "$-prefixed string"
 %token <std::string> DOLLAR_DOLLAR_STRING "$$-prefixed string"
 %token <std::string> DOLLAR_PREF_FIELDNAME "$-prefixed fieldname"
-%token START_PIPELINE START_MATCH
+%token START_PIPELINE START_MATCH START_SORT
 
 //
 // Semantic values (aka the C++ types produced by the actions).
@@ -272,6 +283,10 @@
 %nterm <std::vector<CNode>> expressions values exprZeroToTwo
 %nterm <CNode> matchExpression filterFields filterVal
 
+// Sort related rules
+%nterm <CNode> sortSpecs specList metaSort oneOrNegOne metaSortKeyword
+%nterm <std::pair<CNode::Fieldname, CNode>> sortSpec
+
 %start start;
 //
 // Grammar rules
@@ -287,6 +302,9 @@ start:
         invariant(cst);
         *cst = $matchExpression;
     }
+    | START_SORT sortSpecs {
+        *cst = CNode{$sortSpecs};
+    }
 ;
 
 // Entry point to pipeline parsing.
@@ -398,25 +416,49 @@ projection:
     | javascript
     | symbol
     | javascriptWScope
-    | INT_NON_ZERO {
+    | INT_ONE {
+        $$ = CNode{NonZeroKey{1}};
+    }
+    | INT_NEGATIVE_ONE {
+        $$ = CNode{NonZeroKey{-1}};
+    }
+    | INT_OTHER {
         $$ = CNode{NonZeroKey{$1}};
     }
     | INT_ZERO {
         $$ = CNode{KeyValue::intZeroKey};
     }
-    | LONG_NON_ZERO {
+    | LONG_ONE {
+        $$ = CNode{NonZeroKey{1ll}};
+    }
+    | LONG_NEGATIVE_ONE {
+        $$ = CNode{NonZeroKey{-1ll}};
+    }
+    | LONG_OTHER {
         $$ = CNode{NonZeroKey{$1}};
     }
     | LONG_ZERO {
         $$ = CNode{KeyValue::longZeroKey};
     }
-    | DOUBLE_NON_ZERO {
+    | DOUBLE_ONE {
+        $$ = CNode{NonZeroKey{1.0}};
+    }
+    | DOUBLE_NEGATIVE_ONE {
+        $$ = CNode{NonZeroKey{-1.0}};
+    }
+    | DOUBLE_OTHER {
         $$ = CNode{NonZeroKey{$1}};
     }
     | DOUBLE_ZERO {
         $$ = CNode{KeyValue::doubleZeroKey};
     }
-    | DECIMAL_NON_ZERO {
+    | DECIMAL_ONE {
+        $$ = CNode{NonZeroKey{1.0}};
+    }
+    | DECIMAL_NEGATIVE_ONE {
+        $$ = CNode{NonZeroKey{-1.0}};
+    }
+    | DECIMAL_OTHER {
         $$ = CNode{NonZeroKey{$1}};
     }
     | DECIMAL_ZERO {
@@ -694,6 +736,9 @@ aggExprAsUserFieldname:
     | LTRIM {
         $$ = UserFieldname{"$ltrim"};
     }
+    | META {
+        $$ = UserFieldname{"$meta"};
+    }
     | REGEX_FIND {
         $$ = UserFieldname{"$regexFind"};
     }
@@ -749,7 +794,16 @@ string:
     STRING {
         $$ = CNode{UserString{$1}};
     }
+    // Here we need to list all keys in value BSON positions so they can be converted back to string
+    // in contexts where they're not special. It's laborious but this is the perennial Bison way.
+    | RAND_VAL {
+        $$ = CNode{UserString{"randVal"}};
+    }
+    | TEXT_SCORE {
+        $$ = CNode{UserString{"textScore"}};
+    }
 ;
+
 fieldPath:
     DOLLAR_STRING {
         std::string str = $1;
@@ -846,39 +900,63 @@ maxKey:
 ;
 
 int:
-    INT_NON_ZERO {
+    INT_OTHER {
         $$ = CNode{UserInt{$1}};
     }
     | INT_ZERO {
         $$ = CNode{UserInt{0}};
     }
+    | INT_ONE {
+        $$ = CNode{UserInt{1}};
+    }
+    | INT_NEGATIVE_ONE {
+        $$ = CNode{UserInt{-1}};
+    }
 ;
 
 long:
-    LONG_NON_ZERO {
+    LONG_OTHER {
         $$ = CNode{UserLong{$1}};
     }
     | LONG_ZERO {
         $$ = CNode{UserLong{0ll}};
     }
+    | LONG_ONE {
+        $$ = CNode{UserLong{1ll}};
+    }
+    | LONG_NEGATIVE_ONE {
+        $$ = CNode{UserLong{-1ll}};
+    }
 ;
 
 double:
-    DOUBLE_NON_ZERO {
+    DOUBLE_OTHER {
         $$ = CNode{UserDouble{$1}};
     }
     | DOUBLE_ZERO {
         $$ = CNode{UserDouble{0.0}};
     }
+    | DOUBLE_ONE {
+        $$ = CNode{UserDouble{1.0}};
+    }
+    | DOUBLE_NEGATIVE_ONE {
+        $$ = CNode{UserDouble{-1.0}};
+    }
 ;
 
 decimal:
-    DECIMAL_NON_ZERO {
+    DECIMAL_OTHER {
         $$ = CNode{UserDecimal{$1}};
     }
     | DECIMAL_ZERO {
         $$ = CNode{UserDecimal{0.0}};
     }
+    | DECIMAL_ONE {
+        $$ = CNode{UserDecimal{1.0}};
+    }
+    | DECIMAL_NEGATIVE_ONE {
+        $$ = CNode{UserDecimal{-1.0}};
+    }
 ;
 
 bool:
@@ -1350,6 +1428,70 @@ toUpper:
     }
 ;
 
+metaSortKeyword:
+    RAND_VAL {
+        $$ = CNode{KeyValue::randVal};
+    }
+    | TEXT_SCORE {
+        $$ = CNode{KeyValue::textScore};
+    }
+;
+
+metaSort:
+    START_OBJECT META metaSortKeyword END_OBJECT {
+        $$ = CNode{CNode::ObjectChildren{{KeyFieldname::meta, $metaSortKeyword}}};
+}
+;
+
+sortSpecs:
+    START_OBJECT specList END_OBJECT {
+        $$ = $2;
+}
+
+specList:
+    %empty {
+        $$ = CNode::noopLeaf();
+    }
+    | specList[sortArg] sortSpec {
+        $$ = $sortArg;
+        $$.objectChildren().emplace_back($sortSpec);
+    }
+;
+
+oneOrNegOne:
+    INT_ONE {
+        $$ = CNode{KeyValue::intOneKey};
+    }
+    | INT_NEGATIVE_ONE {
+        $$ = CNode{KeyValue::intNegOneKey};
+    }
+    | LONG_ONE {
+        $$ = CNode{KeyValue::longOneKey};
+    }
+    | LONG_NEGATIVE_ONE {
+        $$ = CNode{KeyValue::longNegOneKey};
+    }
+    | DOUBLE_ONE {
+        $$ = CNode{KeyValue::doubleOneKey};
+    }
+    | DOUBLE_NEGATIVE_ONE {
+        $$ = CNode{KeyValue::doubleNegOneKey};
+    }
+    | DECIMAL_ONE {
+        $$ = CNode{KeyValue::decimalOneKey};
+    }
+    | DECIMAL_NEGATIVE_ONE {
+        $$ = CNode{KeyValue::decimalNegOneKey};
+    }
+
+sortSpec:
+    valueFieldname metaSort {
+        $$ = {$1, $2};
+    } | valueFieldname oneOrNegOne {
+        $$ = {$1, $2};
+    }
+;
+
 literalEscapes:
     const | literal
 ;
diff --git a/src/mongo/db/cst/pipeline_parser_gen.cpp b/src/mongo/db/cst/pipeline_parser_gen.cpp
index da6216a4345..e7bf5ae4429 100644
--- a/src/mongo/db/cst/pipeline_parser_gen.cpp
+++ b/src/mongo/db/cst/pipeline_parser_gen.cpp
@@ -1,4 +1,4 @@
-// A Bison parser, made by GNU Bison 3.5.4.
+// A Bison parser, made by GNU Bison 3.7.
 
 // Skeleton implementation for Bison LALR(1) parsers in C++
 
@@ -30,15 +30,16 @@
 // This special exception was added by the Free Software Foundation in
 // version 2.2 of Bison.
 
-// Undocumented macros, especially those whose name start with YY_,
-// are private implementation details.  Do not rely on them.
+// DO NOT RELY ON FEATURES THAT ARE NOT DOCUMENTED in the manual,
+// especially those whose name start with YY_ or yy_.  They are
+// private implementation details that can be changed or removed.
 
 
 #include "pipeline_parser_gen.hpp"
 
 
 // Unqualified %code blocks.
-#line 83 "src/mongo/db/cst/pipeline_grammar.yy"
+#line 83 "pipeline_grammar.yy"
 
 #include "mongo/db/cst/bson_lexer.h"
 #include "mongo/db/cst/c_node_disambiguation.h"
@@ -59,7 +60,7 @@ void PipelineParserGen::error(const PipelineParserGen::location_type& loc, const
 // mongo.
 #define YYLLOC_DEFAULT(newPos, rhsPositions, nRhs)
 
-#line 67 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 68 "pipeline_parser_gen.cpp"
 
 
 #ifndef YY_
@@ -74,6 +75,7 @@ void PipelineParserGen::error(const PipelineParserGen::location_type& loc, const
 #endif
 #endif
 
+
 // Whether we are compiled with exception support.
 #ifndef YY_EXCEPTIONS
 #if defined __GNUC__ && !defined __EXCEPTIONS
@@ -124,10 +126,10 @@ void PipelineParserGen::error(const PipelineParserGen::location_type& loc, const
             yy_reduce_print_(Rule); \
     } while (false)
 
-#define YY_STACK_PRINT()      \
-    do {                      \
-        if (yydebug_)         \
-            yystack_print_(); \
+#define YY_STACK_PRINT()       \
+    do {                       \
+        if (yydebug_)          \
+            yy_stack_print_(); \
     } while (false)
 
 #else  // !YYDEBUG
@@ -149,47 +151,9 @@ void PipelineParserGen::error(const PipelineParserGen::location_type& loc, const
 #define YYERROR goto yyerrorlab
 #define YYRECOVERING() (!!yyerrstatus_)
 
-#line 58 "src/mongo/db/cst/pipeline_grammar.yy"
+#line 58 "pipeline_grammar.yy"
 namespace mongo {
-#line 159 "src/mongo/db/cst/pipeline_parser_gen.cpp"
-
-
-/* Return YYSTR after stripping away unnecessary quotes and
-   backslashes, so that it's suitable for yyerror.  The heuristic is
-   that double-quoting is unnecessary unless the string contains an
-   apostrophe, a comma, or backslash (other than backslash-backslash).
-   YYSTR is taken from yytname.  */
-std::string PipelineParserGen::yytnamerr_(const char* yystr) {
-    if (*yystr == '"') {
-        std::string yyr;
-        char const* yyp = yystr;
-
-        for (;;)
-            switch (*++yyp) {
-                case '\'':
-                case ',':
-                    goto do_not_strip_quotes;
-
-                case '\\':
-                    if (*++yyp != '\\')
-                        goto do_not_strip_quotes;
-                    else
-                        goto append;
-
-                append:
-                default:
-                    yyr += *yyp;
-                    break;
-
-                case '"':
-                    return yyr;
-            }
-    do_not_strip_quotes:;
-    }
-
-    return yystr;
-}
-
+#line 161 "pipeline_parser_gen.cpp"
 
 /// Build a parser object.
 PipelineParserGen::PipelineParserGen(BSONLexer& lexer_yyarg, CNode* cst_yyarg)
@@ -208,7 +172,7 @@ PipelineParserGen::~PipelineParserGen() {}
 PipelineParserGen::syntax_error::~syntax_error() YY_NOEXCEPT YY_NOTHROW {}
 
 /*---------------.
-| Symbol types.  |
+| symbol kinds.  |
 `---------------*/
 
 
@@ -228,241 +192,247 @@ void PipelineParserGen::by_state::move(by_state& that) {
 
 PipelineParserGen::by_state::by_state(state_type s) YY_NOEXCEPT : state(s) {}
 
-PipelineParserGen::symbol_number_type PipelineParserGen::by_state::type_get() const YY_NOEXCEPT {
+PipelineParserGen::symbol_kind_type PipelineParserGen::by_state::kind() const YY_NOEXCEPT {
     if (state == empty_state)
-        return empty_symbol;
+        return symbol_kind::S_YYEMPTY;
     else
-        return yystos_[+state];
+        return YY_CAST(symbol_kind_type, yystos_[+state]);
 }
 
 PipelineParserGen::stack_symbol_type::stack_symbol_type() {}
 
 PipelineParserGen::stack_symbol_type::stack_symbol_type(YY_RVREF(stack_symbol_type) that)
     : super_type(YY_MOVE(that.state), YY_MOVE(that.location)) {
-    switch (that.type_get()) {
-        case 99:  // "BinData"
+    switch (that.kind()) {
+        case symbol_kind::S_BINARY:  // "BinData"
             value.YY_MOVE_OR_COPY<BSONBinData>(YY_MOVE(that.value));
             break;
 
-        case 106:  // "Code"
+        case symbol_kind::S_JAVASCRIPT:  // "Code"
             value.YY_MOVE_OR_COPY<BSONCode>(YY_MOVE(that.value));
             break;
 
-        case 108:  // "CodeWScope"
+        case symbol_kind::S_JAVASCRIPT_W_SCOPE:  // "CodeWScope"
             value.YY_MOVE_OR_COPY<BSONCodeWScope>(YY_MOVE(that.value));
             break;
 
-        case 105:  // "dbPointer"
+        case symbol_kind::S_DB_POINTER:  // "dbPointer"
             value.YY_MOVE_OR_COPY<BSONDBRef>(YY_MOVE(that.value));
             break;
 
-        case 104:  // "regex"
+        case symbol_kind::S_REGEX:  // "regex"
             value.YY_MOVE_OR_COPY<BSONRegEx>(YY_MOVE(that.value));
             break;
 
-        case 107:  // "Symbol"
+        case symbol_kind::S_SYMBOL:  // "Symbol"
             value.YY_MOVE_OR_COPY<BSONSymbol>(YY_MOVE(that.value));
             break;
 
-        case 135:  // dbPointer
-        case 136:  // javascript
-        case 137:  // symbol
-        case 138:  // javascriptWScope
-        case 139:  // int
-        case 140:  // timestamp
-        case 141:  // long
-        case 142:  // double
-        case 143:  // decimal
-        case 144:  // minKey
-        case 145:  // maxKey
-        case 146:  // value
-        case 147:  // string
-        case 148:  // fieldPath
-        case 149:  // binary
-        case 150:  // undefined
-        case 151:  // objectId
-        case 152:  // bool
-        case 153:  // date
-        case 154:  // null
-        case 155:  // regex
-        case 156:  // simpleValue
-        case 157:  // compoundValue
-        case 158:  // valueArray
-        case 159:  // valueObject
-        case 160:  // valueFields
-        case 161:  // variable
-        case 162:  // pipeline
-        case 163:  // stageList
-        case 164:  // stage
-        case 165:  // inhibitOptimization
-        case 166:  // unionWith
-        case 167:  // skip
-        case 168:  // limit
-        case 169:  // project
-        case 170:  // sample
-        case 171:  // projectFields
-        case 172:  // projection
-        case 173:  // num
-        case 174:  // expression
-        case 175:  // compoundExpression
-        case 176:  // exprFixedTwoArg
-        case 177:  // expressionArray
-        case 178:  // expressionObject
-        case 179:  // expressionFields
-        case 180:  // maths
-        case 181:  // add
-        case 182:  // atan2
-        case 183:  // boolExps
-        case 184:  // and
-        case 185:  // or
-        case 186:  // not
-        case 187:  // literalEscapes
-        case 188:  // const
-        case 189:  // literal
-        case 190:  // stringExps
-        case 191:  // concat
-        case 192:  // dateFromString
-        case 193:  // dateToString
-        case 194:  // indexOfBytes
-        case 195:  // indexOfCP
-        case 196:  // ltrim
-        case 197:  // regexFind
-        case 198:  // regexFindAll
-        case 199:  // regexMatch
-        case 200:  // regexArgs
-        case 201:  // replaceOne
-        case 202:  // replaceAll
-        case 203:  // rtrim
-        case 204:  // split
-        case 205:  // strLenBytes
-        case 206:  // strLenCP
-        case 207:  // strcasecmp
-        case 208:  // substr
-        case 209:  // substrBytes
-        case 210:  // substrCP
-        case 211:  // toLower
-        case 212:  // toUpper
-        case 213:  // trim
-        case 214:  // compExprs
-        case 215:  // cmp
-        case 216:  // eq
-        case 217:  // gt
-        case 218:  // gte
-        case 219:  // lt
-        case 220:  // lte
-        case 221:  // ne
-        case 222:  // typeExpression
-        case 223:  // convert
-        case 224:  // toBool
-        case 225:  // toDate
-        case 226:  // toDecimal
-        case 227:  // toDouble
-        case 228:  // toInt
-        case 229:  // toLong
-        case 230:  // toObjectId
-        case 231:  // toString
-        case 232:  // type
-        case 233:  // abs
-        case 234:  // ceil
-        case 235:  // divide
-        case 236:  // exponent
-        case 237:  // floor
-        case 238:  // ln
-        case 239:  // log
-        case 240:  // logten
-        case 241:  // mod
-        case 242:  // multiply
-        case 243:  // pow
-        case 244:  // round
-        case 245:  // sqrt
-        case 246:  // subtract
-        case 247:  // trunc
-        case 257:  // matchExpression
-        case 258:  // filterFields
-        case 259:  // filterVal
+        case symbol_kind::S_dbPointer:            // dbPointer
+        case symbol_kind::S_javascript:           // javascript
+        case symbol_kind::S_symbol:               // symbol
+        case symbol_kind::S_javascriptWScope:     // javascriptWScope
+        case symbol_kind::S_int:                  // int
+        case symbol_kind::S_timestamp:            // timestamp
+        case symbol_kind::S_long:                 // long
+        case symbol_kind::S_double:               // double
+        case symbol_kind::S_decimal:              // decimal
+        case symbol_kind::S_minKey:               // minKey
+        case symbol_kind::S_maxKey:               // maxKey
+        case symbol_kind::S_value:                // value
+        case symbol_kind::S_string:               // string
+        case symbol_kind::S_fieldPath:            // fieldPath
+        case symbol_kind::S_binary:               // binary
+        case symbol_kind::S_undefined:            // undefined
+        case symbol_kind::S_objectId:             // objectId
+        case symbol_kind::S_bool:                 // bool
+        case symbol_kind::S_date:                 // date
+        case symbol_kind::S_null:                 // null
+        case symbol_kind::S_regex:                // regex
+        case symbol_kind::S_simpleValue:          // simpleValue
+        case symbol_kind::S_compoundValue:        // compoundValue
+        case symbol_kind::S_valueArray:           // valueArray
+        case symbol_kind::S_valueObject:          // valueObject
+        case symbol_kind::S_valueFields:          // valueFields
+        case symbol_kind::S_variable:             // variable
+        case symbol_kind::S_pipeline:             // pipeline
+        case symbol_kind::S_stageList:            // stageList
+        case symbol_kind::S_stage:                // stage
+        case symbol_kind::S_inhibitOptimization:  // inhibitOptimization
+        case symbol_kind::S_unionWith:            // unionWith
+        case symbol_kind::S_skip:                 // skip
+        case symbol_kind::S_limit:                // limit
+        case symbol_kind::S_project:              // project
+        case symbol_kind::S_sample:               // sample
+        case symbol_kind::S_projectFields:        // projectFields
+        case symbol_kind::S_projection:           // projection
+        case symbol_kind::S_num:                  // num
+        case symbol_kind::S_expression:           // expression
+        case symbol_kind::S_compoundExpression:   // compoundExpression
+        case symbol_kind::S_exprFixedTwoArg:      // exprFixedTwoArg
+        case symbol_kind::S_expressionArray:      // expressionArray
+        case symbol_kind::S_expressionObject:     // expressionObject
+        case symbol_kind::S_expressionFields:     // expressionFields
+        case symbol_kind::S_maths:                // maths
+        case symbol_kind::S_add:                  // add
+        case symbol_kind::S_atan2:                // atan2
+        case symbol_kind::S_boolExps:             // boolExps
+        case symbol_kind::S_and:                  // and
+        case symbol_kind::S_or:                   // or
+        case symbol_kind::S_not:                  // not
+        case symbol_kind::S_literalEscapes:       // literalEscapes
+        case symbol_kind::S_const:                // const
+        case symbol_kind::S_literal:              // literal
+        case symbol_kind::S_stringExps:           // stringExps
+        case symbol_kind::S_concat:               // concat
+        case symbol_kind::S_dateFromString:       // dateFromString
+        case symbol_kind::S_dateToString:         // dateToString
+        case symbol_kind::S_indexOfBytes:         // indexOfBytes
+        case symbol_kind::S_indexOfCP:            // indexOfCP
+        case symbol_kind::S_ltrim:                // ltrim
+        case symbol_kind::S_regexFind:            // regexFind
+        case symbol_kind::S_regexFindAll:         // regexFindAll
+        case symbol_kind::S_regexMatch:           // regexMatch
+        case symbol_kind::S_regexArgs:            // regexArgs
+        case symbol_kind::S_replaceOne:           // replaceOne
+        case symbol_kind::S_replaceAll:           // replaceAll
+        case symbol_kind::S_rtrim:                // rtrim
+        case symbol_kind::S_split:                // split
+        case symbol_kind::S_strLenBytes:          // strLenBytes
+        case symbol_kind::S_strLenCP:             // strLenCP
+        case symbol_kind::S_strcasecmp:           // strcasecmp
+        case symbol_kind::S_substr:               // substr
+        case symbol_kind::S_substrBytes:          // substrBytes
+        case symbol_kind::S_substrCP:             // substrCP
+        case symbol_kind::S_toLower:              // toLower
+        case symbol_kind::S_toUpper:              // toUpper
+        case symbol_kind::S_trim:                 // trim
+        case symbol_kind::S_compExprs:            // compExprs
+        case symbol_kind::S_cmp:                  // cmp
+        case symbol_kind::S_eq:                   // eq
+        case symbol_kind::S_gt:                   // gt
+        case symbol_kind::S_gte:                  // gte
+        case symbol_kind::S_lt:                   // lt
+        case symbol_kind::S_lte:                  // lte
+        case symbol_kind::S_ne:                   // ne
+        case symbol_kind::S_typeExpression:       // typeExpression
+        case symbol_kind::S_convert:              // convert
+        case symbol_kind::S_toBool:               // toBool
+        case symbol_kind::S_toDate:               // toDate
+        case symbol_kind::S_toDecimal:            // toDecimal
+        case symbol_kind::S_toDouble:             // toDouble
+        case symbol_kind::S_toInt:                // toInt
+        case symbol_kind::S_toLong:               // toLong
+        case symbol_kind::S_toObjectId:           // toObjectId
+        case symbol_kind::S_toString:             // toString
+        case symbol_kind::S_type:                 // type
+        case symbol_kind::S_abs:                  // abs
+        case symbol_kind::S_ceil:                 // ceil
+        case symbol_kind::S_divide:               // divide
+        case symbol_kind::S_exponent:             // exponent
+        case symbol_kind::S_floor:                // floor
+        case symbol_kind::S_ln:                   // ln
+        case symbol_kind::S_log:                  // log
+        case symbol_kind::S_logten:               // logten
+        case symbol_kind::S_mod:                  // mod
+        case symbol_kind::S_multiply:             // multiply
+        case symbol_kind::S_pow:                  // pow
+        case symbol_kind::S_round:                // round
+        case symbol_kind::S_sqrt:                 // sqrt
+        case symbol_kind::S_subtract:             // subtract
+        case symbol_kind::S_trunc:                // trunc
+        case symbol_kind::S_matchExpression:      // matchExpression
+        case symbol_kind::S_filterFields:         // filterFields
+        case symbol_kind::S_filterVal:            // filterVal
+        case symbol_kind::S_sortSpecs:            // sortSpecs
+        case symbol_kind::S_specList:             // specList
+        case symbol_kind::S_metaSort:             // metaSort
+        case symbol_kind::S_oneOrNegOne:          // oneOrNegOne
+        case symbol_kind::S_metaSortKeyword:      // metaSortKeyword
             value.YY_MOVE_OR_COPY<CNode>(YY_MOVE(that.value));
             break;
 
-        case 122:  // projectionFieldname
-        case 123:  // expressionFieldname
-        case 124:  // stageAsUserFieldname
-        case 125:  // filterFieldname
-        case 126:  // argAsUserFieldname
-        case 127:  // aggExprAsUserFieldname
-        case 128:  // invariableUserFieldname
-        case 129:  // idAsUserFieldname
-        case 130:  // valueFieldname
+        case symbol_kind::S_projectionFieldname:      // projectionFieldname
+        case symbol_kind::S_expressionFieldname:      // expressionFieldname
+        case symbol_kind::S_stageAsUserFieldname:     // stageAsUserFieldname
+        case symbol_kind::S_filterFieldname:          // filterFieldname
+        case symbol_kind::S_argAsUserFieldname:       // argAsUserFieldname
+        case symbol_kind::S_aggExprAsUserFieldname:   // aggExprAsUserFieldname
+        case symbol_kind::S_invariableUserFieldname:  // invariableUserFieldname
+        case symbol_kind::S_idAsUserFieldname:        // idAsUserFieldname
+        case symbol_kind::S_valueFieldname:           // valueFieldname
             value.YY_MOVE_OR_COPY<CNode::Fieldname>(YY_MOVE(that.value));
             break;
 
-        case 102:  // "Date"
+        case symbol_kind::S_DATE_LITERAL:  // "Date"
             value.YY_MOVE_OR_COPY<Date_t>(YY_MOVE(that.value));
             break;
 
-        case 112:  // "non-zero decimal"
+        case symbol_kind::S_DECIMAL_OTHER:  // "arbitrary decimal"
             value.YY_MOVE_OR_COPY<Decimal128>(YY_MOVE(that.value));
             break;
 
-        case 101:  // "ObjectID"
+        case symbol_kind::S_OBJECT_ID:  // "ObjectID"
             value.YY_MOVE_OR_COPY<OID>(YY_MOVE(that.value));
             break;
 
-        case 113:  // "Timestamp"
+        case symbol_kind::S_TIMESTAMP:  // "Timestamp"
             value.YY_MOVE_OR_COPY<Timestamp>(YY_MOVE(that.value));
             break;
 
-        case 115:  // "maxKey"
+        case symbol_kind::S_MAX_KEY:  // "maxKey"
             value.YY_MOVE_OR_COPY<UserMaxKey>(YY_MOVE(that.value));
             break;
 
-        case 114:  // "minKey"
+        case symbol_kind::S_MIN_KEY:  // "minKey"
             value.YY_MOVE_OR_COPY<UserMinKey>(YY_MOVE(that.value));
             break;
 
-        case 103:  // "null"
+        case symbol_kind::S_JSNULL:  // "null"
             value.YY_MOVE_OR_COPY<UserNull>(YY_MOVE(that.value));
             break;
 
-        case 100:  // "undefined"
+        case symbol_kind::S_UNDEFINED:  // "undefined"
             value.YY_MOVE_OR_COPY<UserUndefined>(YY_MOVE(that.value));
             break;
 
-        case 111:  // "non-zero double"
+        case symbol_kind::S_DOUBLE_OTHER:  // "arbitrary double"
             value.YY_MOVE_OR_COPY<double>(YY_MOVE(that.value));
             break;
 
-        case 109:  // "non-zero integer"
+        case symbol_kind::S_INT_OTHER:  // "arbitrary integer"
             value.YY_MOVE_OR_COPY<int>(YY_MOVE(that.value));
             break;
 
-        case 110:  // "non-zero long"
+        case symbol_kind::S_LONG_OTHER:  // "arbitrary long"
             value.YY_MOVE_OR_COPY<long long>(YY_MOVE(that.value));
             break;
 
-        case 131:  // projectField
-        case 132:  // expressionField
-        case 133:  // valueField
-        case 134:  // filterField
-        case 248:  // onErrorArg
-        case 249:  // onNullArg
-        case 250:  // formatArg
-        case 251:  // timezoneArg
-        case 252:  // charsArg
-        case 253:  // optionsArg
+        case symbol_kind::S_projectField:     // projectField
+        case symbol_kind::S_expressionField:  // expressionField
+        case symbol_kind::S_valueField:       // valueField
+        case symbol_kind::S_filterField:      // filterField
+        case symbol_kind::S_onErrorArg:       // onErrorArg
+        case symbol_kind::S_onNullArg:        // onNullArg
+        case symbol_kind::S_formatArg:        // formatArg
+        case symbol_kind::S_timezoneArg:      // timezoneArg
+        case symbol_kind::S_charsArg:         // charsArg
+        case symbol_kind::S_optionsArg:       // optionsArg
+        case symbol_kind::S_sortSpec:         // sortSpec
             value.YY_MOVE_OR_COPY<std::pair<CNode::Fieldname, CNode>>(YY_MOVE(that.value));
             break;
 
-        case 97:   // "fieldname"
-        case 98:   // "string"
-        case 116:  // "$-prefixed string"
-        case 117:  // "$$-prefixed string"
-        case 118:  // "$-prefixed fieldname"
+        case symbol_kind::S_FIELDNAME:              // "fieldname"
+        case symbol_kind::S_STRING:                 // "string"
+        case symbol_kind::S_DOLLAR_STRING:          // "$-prefixed string"
+        case symbol_kind::S_DOLLAR_DOLLAR_STRING:   // "$$-prefixed string"
+        case symbol_kind::S_DOLLAR_PREF_FIELDNAME:  // "$-prefixed fieldname"
             value.YY_MOVE_OR_COPY<std::string>(YY_MOVE(that.value));
             break;
 
-        case 254:  // expressions
-        case 255:  // values
-        case 256:  // exprZeroToTwo
+        case symbol_kind::S_expressions:    // expressions
+        case symbol_kind::S_values:         // values
+        case symbol_kind::S_exprZeroToTwo:  // exprZeroToTwo
             value.YY_MOVE_OR_COPY<std::vector<CNode>>(YY_MOVE(that.value));
             break;
 
@@ -478,230 +448,236 @@ PipelineParserGen::stack_symbol_type::stack_symbol_type(YY_RVREF(stack_symbol_ty
 
 PipelineParserGen::stack_symbol_type::stack_symbol_type(state_type s, YY_MOVE_REF(symbol_type) that)
     : super_type(s, YY_MOVE(that.location)) {
-    switch (that.type_get()) {
-        case 99:  // "BinData"
+    switch (that.kind()) {
+        case symbol_kind::S_BINARY:  // "BinData"
             value.move<BSONBinData>(YY_MOVE(that.value));
             break;
 
-        case 106:  // "Code"
+        case symbol_kind::S_JAVASCRIPT:  // "Code"
             value.move<BSONCode>(YY_MOVE(that.value));
             break;
 
-        case 108:  // "CodeWScope"
+        case symbol_kind::S_JAVASCRIPT_W_SCOPE:  // "CodeWScope"
             value.move<BSONCodeWScope>(YY_MOVE(that.value));
             break;
 
-        case 105:  // "dbPointer"
+        case symbol_kind::S_DB_POINTER:  // "dbPointer"
             value.move<BSONDBRef>(YY_MOVE(that.value));
             break;
 
-        case 104:  // "regex"
+        case symbol_kind::S_REGEX:  // "regex"
             value.move<BSONRegEx>(YY_MOVE(that.value));
             break;
 
-        case 107:  // "Symbol"
+        case symbol_kind::S_SYMBOL:  // "Symbol"
             value.move<BSONSymbol>(YY_MOVE(that.value));
             break;
 
-        case 135:  // dbPointer
-        case 136:  // javascript
-        case 137:  // symbol
-        case 138:  // javascriptWScope
-        case 139:  // int
-        case 140:  // timestamp
-        case 141:  // long
-        case 142:  // double
-        case 143:  // decimal
-        case 144:  // minKey
-        case 145:  // maxKey
-        case 146:  // value
-        case 147:  // string
-        case 148:  // fieldPath
-        case 149:  // binary
-        case 150:  // undefined
-        case 151:  // objectId
-        case 152:  // bool
-        case 153:  // date
-        case 154:  // null
-        case 155:  // regex
-        case 156:  // simpleValue
-        case 157:  // compoundValue
-        case 158:  // valueArray
-        case 159:  // valueObject
-        case 160:  // valueFields
-        case 161:  // variable
-        case 162:  // pipeline
-        case 163:  // stageList
-        case 164:  // stage
-        case 165:  // inhibitOptimization
-        case 166:  // unionWith
-        case 167:  // skip
-        case 168:  // limit
-        case 169:  // project
-        case 170:  // sample
-        case 171:  // projectFields
-        case 172:  // projection
-        case 173:  // num
-        case 174:  // expression
-        case 175:  // compoundExpression
-        case 176:  // exprFixedTwoArg
-        case 177:  // expressionArray
-        case 178:  // expressionObject
-        case 179:  // expressionFields
-        case 180:  // maths
-        case 181:  // add
-        case 182:  // atan2
-        case 183:  // boolExps
-        case 184:  // and
-        case 185:  // or
-        case 186:  // not
-        case 187:  // literalEscapes
-        case 188:  // const
-        case 189:  // literal
-        case 190:  // stringExps
-        case 191:  // concat
-        case 192:  // dateFromString
-        case 193:  // dateToString
-        case 194:  // indexOfBytes
-        case 195:  // indexOfCP
-        case 196:  // ltrim
-        case 197:  // regexFind
-        case 198:  // regexFindAll
-        case 199:  // regexMatch
-        case 200:  // regexArgs
-        case 201:  // replaceOne
-        case 202:  // replaceAll
-        case 203:  // rtrim
-        case 204:  // split
-        case 205:  // strLenBytes
-        case 206:  // strLenCP
-        case 207:  // strcasecmp
-        case 208:  // substr
-        case 209:  // substrBytes
-        case 210:  // substrCP
-        case 211:  // toLower
-        case 212:  // toUpper
-        case 213:  // trim
-        case 214:  // compExprs
-        case 215:  // cmp
-        case 216:  // eq
-        case 217:  // gt
-        case 218:  // gte
-        case 219:  // lt
-        case 220:  // lte
-        case 221:  // ne
-        case 222:  // typeExpression
-        case 223:  // convert
-        case 224:  // toBool
-        case 225:  // toDate
-        case 226:  // toDecimal
-        case 227:  // toDouble
-        case 228:  // toInt
-        case 229:  // toLong
-        case 230:  // toObjectId
-        case 231:  // toString
-        case 232:  // type
-        case 233:  // abs
-        case 234:  // ceil
-        case 235:  // divide
-        case 236:  // exponent
-        case 237:  // floor
-        case 238:  // ln
-        case 239:  // log
-        case 240:  // logten
-        case 241:  // mod
-        case 242:  // multiply
-        case 243:  // pow
-        case 244:  // round
-        case 245:  // sqrt
-        case 246:  // subtract
-        case 247:  // trunc
-        case 257:  // matchExpression
-        case 258:  // filterFields
-        case 259:  // filterVal
+        case symbol_kind::S_dbPointer:            // dbPointer
+        case symbol_kind::S_javascript:           // javascript
+        case symbol_kind::S_symbol:               // symbol
+        case symbol_kind::S_javascriptWScope:     // javascriptWScope
+        case symbol_kind::S_int:                  // int
+        case symbol_kind::S_timestamp:            // timestamp
+        case symbol_kind::S_long:                 // long
+        case symbol_kind::S_double:               // double
+        case symbol_kind::S_decimal:              // decimal
+        case symbol_kind::S_minKey:               // minKey
+        case symbol_kind::S_maxKey:               // maxKey
+        case symbol_kind::S_value:                // value
+        case symbol_kind::S_string:               // string
+        case symbol_kind::S_fieldPath:            // fieldPath
+        case symbol_kind::S_binary:               // binary
+        case symbol_kind::S_undefined:            // undefined
+        case symbol_kind::S_objectId:             // objectId
+        case symbol_kind::S_bool:                 // bool
+        case symbol_kind::S_date:                 // date
+        case symbol_kind::S_null:                 // null
+        case symbol_kind::S_regex:                // regex
+        case symbol_kind::S_simpleValue:          // simpleValue
+        case symbol_kind::S_compoundValue:        // compoundValue
+        case symbol_kind::S_valueArray:           // valueArray
+        case symbol_kind::S_valueObject:          // valueObject
+        case symbol_kind::S_valueFields:          // valueFields
+        case symbol_kind::S_variable:             // variable
+        case symbol_kind::S_pipeline:             // pipeline
+        case symbol_kind::S_stageList:            // stageList
+        case symbol_kind::S_stage:                // stage
+        case symbol_kind::S_inhibitOptimization:  // inhibitOptimization
+        case symbol_kind::S_unionWith:            // unionWith
+        case symbol_kind::S_skip:                 // skip
+        case symbol_kind::S_limit:                // limit
+        case symbol_kind::S_project:              // project
+        case symbol_kind::S_sample:               // sample
+        case symbol_kind::S_projectFields:        // projectFields
+        case symbol_kind::S_projection:           // projection
+        case symbol_kind::S_num:                  // num
+        case symbol_kind::S_expression:           // expression
+        case symbol_kind::S_compoundExpression:   // compoundExpression
+        case symbol_kind::S_exprFixedTwoArg:      // exprFixedTwoArg
+        case symbol_kind::S_expressionArray:      // expressionArray
+        case symbol_kind::S_expressionObject:     // expressionObject
+        case symbol_kind::S_expressionFields:     // expressionFields
+        case symbol_kind::S_maths:                // maths
+        case symbol_kind::S_add:                  // add
+        case symbol_kind::S_atan2:                // atan2
+        case symbol_kind::S_boolExps:             // boolExps
+        case symbol_kind::S_and:                  // and
+        case symbol_kind::S_or:                   // or
+        case symbol_kind::S_not:                  // not
+        case symbol_kind::S_literalEscapes:       // literalEscapes
+        case symbol_kind::S_const:                // const
+        case symbol_kind::S_literal:              // literal
+        case symbol_kind::S_stringExps:           // stringExps
+        case symbol_kind::S_concat:               // concat
+        case symbol_kind::S_dateFromString:       // dateFromString
+        case symbol_kind::S_dateToString:         // dateToString
+        case symbol_kind::S_indexOfBytes:         // indexOfBytes
+        case symbol_kind::S_indexOfCP:            // indexOfCP
+        case symbol_kind::S_ltrim:                // ltrim
+        case symbol_kind::S_regexFind:            // regexFind
+        case symbol_kind::S_regexFindAll:         // regexFindAll
+        case symbol_kind::S_regexMatch:           // regexMatch
+        case symbol_kind::S_regexArgs:            // regexArgs
+        case symbol_kind::S_replaceOne:           // replaceOne
+        case symbol_kind::S_replaceAll:           // replaceAll
+        case symbol_kind::S_rtrim:                // rtrim
+        case symbol_kind::S_split:                // split
+        case symbol_kind::S_strLenBytes:          // strLenBytes
+        case symbol_kind::S_strLenCP:             // strLenCP
+        case symbol_kind::S_strcasecmp:           // strcasecmp
+        case symbol_kind::S_substr:               // substr
+        case symbol_kind::S_substrBytes:          // substrBytes
+        case symbol_kind::S_substrCP:             // substrCP
+        case symbol_kind::S_toLower:              // toLower
+        case symbol_kind::S_toUpper:              // toUpper
+        case symbol_kind::S_trim:                 // trim
+        case symbol_kind::S_compExprs:            // compExprs
+        case symbol_kind::S_cmp:                  // cmp
+        case symbol_kind::S_eq:                   // eq
+        case symbol_kind::S_gt:                   // gt
+        case symbol_kind::S_gte:                  // gte
+        case symbol_kind::S_lt:                   // lt
+        case symbol_kind::S_lte:                  // lte
+        case symbol_kind::S_ne:                   // ne
+        case symbol_kind::S_typeExpression:       // typeExpression
+        case symbol_kind::S_convert:              // convert
+        case symbol_kind::S_toBool:               // toBool
+        case symbol_kind::S_toDate:               // toDate
+        case symbol_kind::S_toDecimal:            // toDecimal
+        case symbol_kind::S_toDouble:             // toDouble
+        case symbol_kind::S_toInt:                // toInt
+        case symbol_kind::S_toLong:               // toLong
+        case symbol_kind::S_toObjectId:           // toObjectId
+        case symbol_kind::S_toString:             // toString
+        case symbol_kind::S_type:                 // type
+        case symbol_kind::S_abs:                  // abs
+        case symbol_kind::S_ceil:                 // ceil
+        case symbol_kind::S_divide:               // divide
+        case symbol_kind::S_exponent:             // exponent
+        case symbol_kind::S_floor:                // floor
+        case symbol_kind::S_ln:                   // ln
+        case symbol_kind::S_log:                  // log
+        case symbol_kind::S_logten:               // logten
+        case symbol_kind::S_mod:                  // mod
+        case symbol_kind::S_multiply:             // multiply
+        case symbol_kind::S_pow:                  // pow
+        case symbol_kind::S_round:                // round
+        case symbol_kind::S_sqrt:                 // sqrt
+        case symbol_kind::S_subtract:             // subtract
+        case symbol_kind::S_trunc:                // trunc
+        case symbol_kind::S_matchExpression:      // matchExpression
+        case symbol_kind::S_filterFields:         // filterFields
+        case symbol_kind::S_filterVal:            // filterVal
+        case symbol_kind::S_sortSpecs:            // sortSpecs
+        case symbol_kind::S_specList:             // specList
+        case symbol_kind::S_metaSort:             // metaSort
+        case symbol_kind::S_oneOrNegOne:          // oneOrNegOne
+        case symbol_kind::S_metaSortKeyword:      // metaSortKeyword
             value.move<CNode>(YY_MOVE(that.value));
             break;
 
-        case 122:  // projectionFieldname
-        case 123:  // expressionFieldname
-        case 124:  // stageAsUserFieldname
-        case 125:  // filterFieldname
-        case 126:  // argAsUserFieldname
-        case 127:  // aggExprAsUserFieldname
-        case 128:  // invariableUserFieldname
-        case 129:  // idAsUserFieldname
-        case 130:  // valueFieldname
+        case symbol_kind::S_projectionFieldname:      // projectionFieldname
+        case symbol_kind::S_expressionFieldname:      // expressionFieldname
+        case symbol_kind::S_stageAsUserFieldname:     // stageAsUserFieldname
+        case symbol_kind::S_filterFieldname:          // filterFieldname
+        case symbol_kind::S_argAsUserFieldname:       // argAsUserFieldname
+        case symbol_kind::S_aggExprAsUserFieldname:   // aggExprAsUserFieldname
+        case symbol_kind::S_invariableUserFieldname:  // invariableUserFieldname
+        case symbol_kind::S_idAsUserFieldname:        // idAsUserFieldname
+        case symbol_kind::S_valueFieldname:           // valueFieldname
             value.move<CNode::Fieldname>(YY_MOVE(that.value));
             break;
 
-        case 102:  // "Date"
+        case symbol_kind::S_DATE_LITERAL:  // "Date"
             value.move<Date_t>(YY_MOVE(that.value));
             break;
 
-        case 112:  // "non-zero decimal"
+        case symbol_kind::S_DECIMAL_OTHER:  // "arbitrary decimal"
             value.move<Decimal128>(YY_MOVE(that.value));
             break;
 
-        case 101:  // "ObjectID"
+        case symbol_kind::S_OBJECT_ID:  // "ObjectID"
             value.move<OID>(YY_MOVE(that.value));
             break;
 
-        case 113:  // "Timestamp"
+        case symbol_kind::S_TIMESTAMP:  // "Timestamp"
             value.move<Timestamp>(YY_MOVE(that.value));
             break;
 
-        case 115:  // "maxKey"
+        case symbol_kind::S_MAX_KEY:  // "maxKey"
             value.move<UserMaxKey>(YY_MOVE(that.value));
             break;
 
-        case 114:  // "minKey"
+        case symbol_kind::S_MIN_KEY:  // "minKey"
             value.move<UserMinKey>(YY_MOVE(that.value));
             break;
 
-        case 103:  // "null"
+        case symbol_kind::S_JSNULL:  // "null"
             value.move<UserNull>(YY_MOVE(that.value));
             break;
 
-        case 100:  // "undefined"
+        case symbol_kind::S_UNDEFINED:  // "undefined"
             value.move<UserUndefined>(YY_MOVE(that.value));
             break;
 
-        case 111:  // "non-zero double"
+        case symbol_kind::S_DOUBLE_OTHER:  // "arbitrary double"
             value.move<double>(YY_MOVE(that.value));
             break;
 
-        case 109:  // "non-zero integer"
+        case symbol_kind::S_INT_OTHER:  // "arbitrary integer"
             value.move<int>(YY_MOVE(that.value));
             break;
 
-        case 110:  // "non-zero long"
+        case symbol_kind::S_LONG_OTHER:  // "arbitrary long"
             value.move<long long>(YY_MOVE(that.value));
             break;
 
-        case 131:  // projectField
-        case 132:  // expressionField
-        case 133:  // valueField
-        case 134:  // filterField
-        case 248:  // onErrorArg
-        case 249:  // onNullArg
-        case 250:  // formatArg
-        case 251:  // timezoneArg
-        case 252:  // charsArg
-        case 253:  // optionsArg
+        case symbol_kind::S_projectField:     // projectField
+        case symbol_kind::S_expressionField:  // expressionField
+        case symbol_kind::S_valueField:       // valueField
+        case symbol_kind::S_filterField:      // filterField
+        case symbol_kind::S_onErrorArg:       // onErrorArg
+        case symbol_kind::S_onNullArg:        // onNullArg
+        case symbol_kind::S_formatArg:        // formatArg
+        case symbol_kind::S_timezoneArg:      // timezoneArg
+        case symbol_kind::S_charsArg:         // charsArg
+        case symbol_kind::S_optionsArg:       // optionsArg
+        case symbol_kind::S_sortSpec:         // sortSpec
             value.move<std::pair<CNode::Fieldname, CNode>>(YY_MOVE(that.value));
             break;
 
-        case 97:   // "fieldname"
-        case 98:   // "string"
-        case 116:  // "$-prefixed string"
-        case 117:  // "$$-prefixed string"
-        case 118:  // "$-prefixed fieldname"
+        case symbol_kind::S_FIELDNAME:              // "fieldname"
+        case symbol_kind::S_STRING:                 // "string"
+        case symbol_kind::S_DOLLAR_STRING:          // "$-prefixed string"
+        case symbol_kind::S_DOLLAR_DOLLAR_STRING:   // "$$-prefixed string"
+        case symbol_kind::S_DOLLAR_PREF_FIELDNAME:  // "$-prefixed fieldname"
             value.move<std::string>(YY_MOVE(that.value));
             break;
 
-        case 254:  // expressions
-        case 255:  // values
-        case 256:  // exprZeroToTwo
+        case symbol_kind::S_expressions:    // expressions
+        case symbol_kind::S_values:         // values
+        case symbol_kind::S_exprZeroToTwo:  // exprZeroToTwo
             value.move<std::vector<CNode>>(YY_MOVE(that.value));
             break;
 
@@ -710,237 +686,243 @@ PipelineParserGen::stack_symbol_type::stack_symbol_type(state_type s, YY_MOVE_RE
     }
 
     // that is emptied.
-    that.type = empty_symbol;
+    that.kind_ = symbol_kind::S_YYEMPTY;
 }
 
 #if YY_CPLUSPLUS < 201103L
 PipelineParserGen::stack_symbol_type& PipelineParserGen::stack_symbol_type::operator=(
     const stack_symbol_type& that) {
     state = that.state;
-    switch (that.type_get()) {
-        case 99:  // "BinData"
+    switch (that.kind()) {
+        case symbol_kind::S_BINARY:  // "BinData"
             value.copy<BSONBinData>(that.value);
             break;
 
-        case 106:  // "Code"
+        case symbol_kind::S_JAVASCRIPT:  // "Code"
             value.copy<BSONCode>(that.value);
             break;
 
-        case 108:  // "CodeWScope"
+        case symbol_kind::S_JAVASCRIPT_W_SCOPE:  // "CodeWScope"
             value.copy<BSONCodeWScope>(that.value);
             break;
 
-        case 105:  // "dbPointer"
+        case symbol_kind::S_DB_POINTER:  // "dbPointer"
             value.copy<BSONDBRef>(that.value);
             break;
 
-        case 104:  // "regex"
+        case symbol_kind::S_REGEX:  // "regex"
             value.copy<BSONRegEx>(that.value);
             break;
 
-        case 107:  // "Symbol"
+        case symbol_kind::S_SYMBOL:  // "Symbol"
             value.copy<BSONSymbol>(that.value);
             break;
 
-        case 135:  // dbPointer
-        case 136:  // javascript
-        case 137:  // symbol
-        case 138:  // javascriptWScope
-        case 139:  // int
-        case 140:  // timestamp
-        case 141:  // long
-        case 142:  // double
-        case 143:  // decimal
-        case 144:  // minKey
-        case 145:  // maxKey
-        case 146:  // value
-        case 147:  // string
-        case 148:  // fieldPath
-        case 149:  // binary
-        case 150:  // undefined
-        case 151:  // objectId
-        case 152:  // bool
-        case 153:  // date
-        case 154:  // null
-        case 155:  // regex
-        case 156:  // simpleValue
-        case 157:  // compoundValue
-        case 158:  // valueArray
-        case 159:  // valueObject
-        case 160:  // valueFields
-        case 161:  // variable
-        case 162:  // pipeline
-        case 163:  // stageList
-        case 164:  // stage
-        case 165:  // inhibitOptimization
-        case 166:  // unionWith
-        case 167:  // skip
-        case 168:  // limit
-        case 169:  // project
-        case 170:  // sample
-        case 171:  // projectFields
-        case 172:  // projection
-        case 173:  // num
-        case 174:  // expression
-        case 175:  // compoundExpression
-        case 176:  // exprFixedTwoArg
-        case 177:  // expressionArray
-        case 178:  // expressionObject
-        case 179:  // expressionFields
-        case 180:  // maths
-        case 181:  // add
-        case 182:  // atan2
-        case 183:  // boolExps
-        case 184:  // and
-        case 185:  // or
-        case 186:  // not
-        case 187:  // literalEscapes
-        case 188:  // const
-        case 189:  // literal
-        case 190:  // stringExps
-        case 191:  // concat
-        case 192:  // dateFromString
-        case 193:  // dateToString
-        case 194:  // indexOfBytes
-        case 195:  // indexOfCP
-        case 196:  // ltrim
-        case 197:  // regexFind
-        case 198:  // regexFindAll
-        case 199:  // regexMatch
-        case 200:  // regexArgs
-        case 201:  // replaceOne
-        case 202:  // replaceAll
-        case 203:  // rtrim
-        case 204:  // split
-        case 205:  // strLenBytes
-        case 206:  // strLenCP
-        case 207:  // strcasecmp
-        case 208:  // substr
-        case 209:  // substrBytes
-        case 210:  // substrCP
-        case 211:  // toLower
-        case 212:  // toUpper
-        case 213:  // trim
-        case 214:  // compExprs
-        case 215:  // cmp
-        case 216:  // eq
-        case 217:  // gt
-        case 218:  // gte
-        case 219:  // lt
-        case 220:  // lte
-        case 221:  // ne
-        case 222:  // typeExpression
-        case 223:  // convert
-        case 224:  // toBool
-        case 225:  // toDate
-        case 226:  // toDecimal
-        case 227:  // toDouble
-        case 228:  // toInt
-        case 229:  // toLong
-        case 230:  // toObjectId
-        case 231:  // toString
-        case 232:  // type
-        case 233:  // abs
-        case 234:  // ceil
-        case 235:  // divide
-        case 236:  // exponent
-        case 237:  // floor
-        case 238:  // ln
-        case 239:  // log
-        case 240:  // logten
-        case 241:  // mod
-        case 242:  // multiply
-        case 243:  // pow
-        case 244:  // round
-        case 245:  // sqrt
-        case 246:  // subtract
-        case 247:  // trunc
-        case 257:  // matchExpression
-        case 258:  // filterFields
-        case 259:  // filterVal
+        case symbol_kind::S_dbPointer:            // dbPointer
+        case symbol_kind::S_javascript:           // javascript
+        case symbol_kind::S_symbol:               // symbol
+        case symbol_kind::S_javascriptWScope:     // javascriptWScope
+        case symbol_kind::S_int:                  // int
+        case symbol_kind::S_timestamp:            // timestamp
+        case symbol_kind::S_long:                 // long
+        case symbol_kind::S_double:               // double
+        case symbol_kind::S_decimal:              // decimal
+        case symbol_kind::S_minKey:               // minKey
+        case symbol_kind::S_maxKey:               // maxKey
+        case symbol_kind::S_value:                // value
+        case symbol_kind::S_string:               // string
+        case symbol_kind::S_fieldPath:            // fieldPath
+        case symbol_kind::S_binary:               // binary
+        case symbol_kind::S_undefined:            // undefined
+        case symbol_kind::S_objectId:             // objectId
+        case symbol_kind::S_bool:                 // bool
+        case symbol_kind::S_date:                 // date
+        case symbol_kind::S_null:                 // null
+        case symbol_kind::S_regex:                // regex
+        case symbol_kind::S_simpleValue:          // simpleValue
+        case symbol_kind::S_compoundValue:        // compoundValue
+        case symbol_kind::S_valueArray:           // valueArray
+        case symbol_kind::S_valueObject:          // valueObject
+        case symbol_kind::S_valueFields:          // valueFields
+        case symbol_kind::S_variable:             // variable
+        case symbol_kind::S_pipeline:             // pipeline
+        case symbol_kind::S_stageList:            // stageList
+        case symbol_kind::S_stage:                // stage
+        case symbol_kind::S_inhibitOptimization:  // inhibitOptimization
+        case symbol_kind::S_unionWith:            // unionWith
+        case symbol_kind::S_skip:                 // skip
+        case symbol_kind::S_limit:                // limit
+        case symbol_kind::S_project:              // project
+        case symbol_kind::S_sample:               // sample
+        case symbol_kind::S_projectFields:        // projectFields
+        case symbol_kind::S_projection:           // projection
+        case symbol_kind::S_num:                  // num
+        case symbol_kind::S_expression:           // expression
+        case symbol_kind::S_compoundExpression:   // compoundExpression
+        case symbol_kind::S_exprFixedTwoArg:      // exprFixedTwoArg
+        case symbol_kind::S_expressionArray:      // expressionArray
+        case symbol_kind::S_expressionObject:     // expressionObject
+        case symbol_kind::S_expressionFields:     // expressionFields
+        case symbol_kind::S_maths:                // maths
+        case symbol_kind::S_add:                  // add
+        case symbol_kind::S_atan2:                // atan2
+        case symbol_kind::S_boolExps:             // boolExps
+        case symbol_kind::S_and:                  // and
+        case symbol_kind::S_or:                   // or
+        case symbol_kind::S_not:                  // not
+        case symbol_kind::S_literalEscapes:       // literalEscapes
+        case symbol_kind::S_const:                // const
+        case symbol_kind::S_literal:              // literal
+        case symbol_kind::S_stringExps:           // stringExps
+        case symbol_kind::S_concat:               // concat
+        case symbol_kind::S_dateFromString:       // dateFromString
+        case symbol_kind::S_dateToString:         // dateToString
+        case symbol_kind::S_indexOfBytes:         // indexOfBytes
+        case symbol_kind::S_indexOfCP:            // indexOfCP
+        case symbol_kind::S_ltrim:                // ltrim
+        case symbol_kind::S_regexFind:            // regexFind
+        case symbol_kind::S_regexFindAll:         // regexFindAll
+        case symbol_kind::S_regexMatch:           // regexMatch
+        case symbol_kind::S_regexArgs:            // regexArgs
+        case symbol_kind::S_replaceOne:           // replaceOne
+        case symbol_kind::S_replaceAll:           // replaceAll
+        case symbol_kind::S_rtrim:                // rtrim
+        case symbol_kind::S_split:                // split
+        case symbol_kind::S_strLenBytes:          // strLenBytes
+        case symbol_kind::S_strLenCP:             // strLenCP
+        case symbol_kind::S_strcasecmp:           // strcasecmp
+        case symbol_kind::S_substr:               // substr
+        case symbol_kind::S_substrBytes:          // substrBytes
+        case symbol_kind::S_substrCP:             // substrCP
+        case symbol_kind::S_toLower:              // toLower
+        case symbol_kind::S_toUpper:              // toUpper
+        case symbol_kind::S_trim:                 // trim
+        case symbol_kind::S_compExprs:            // compExprs
+        case symbol_kind::S_cmp:                  // cmp
+        case symbol_kind::S_eq:                   // eq
+        case symbol_kind::S_gt:                   // gt
+        case symbol_kind::S_gte:                  // gte
+        case symbol_kind::S_lt:                   // lt
+        case symbol_kind::S_lte:                  // lte
+        case symbol_kind::S_ne:                   // ne
+        case symbol_kind::S_typeExpression:       // typeExpression
+        case symbol_kind::S_convert:              // convert
+        case symbol_kind::S_toBool:               // toBool
+        case symbol_kind::S_toDate:               // toDate
+        case symbol_kind::S_toDecimal:            // toDecimal
+        case symbol_kind::S_toDouble:             // toDouble
+        case symbol_kind::S_toInt:                // toInt
+        case symbol_kind::S_toLong:               // toLong
+        case symbol_kind::S_toObjectId:           // toObjectId
+        case symbol_kind::S_toString:             // toString
+        case symbol_kind::S_type:                 // type
+        case symbol_kind::S_abs:                  // abs
+        case symbol_kind::S_ceil:                 // ceil
+        case symbol_kind::S_divide:               // divide
+        case symbol_kind::S_exponent:             // exponent
+        case symbol_kind::S_floor:                // floor
+        case symbol_kind::S_ln:                   // ln
+        case symbol_kind::S_log:                  // log
+        case symbol_kind::S_logten:               // logten
+        case symbol_kind::S_mod:                  // mod
+        case symbol_kind::S_multiply:             // multiply
+        case symbol_kind::S_pow:                  // pow
+        case symbol_kind::S_round:                // round
+        case symbol_kind::S_sqrt:                 // sqrt
+        case symbol_kind::S_subtract:             // subtract
+        case symbol_kind::S_trunc:                // trunc
+        case symbol_kind::S_matchExpression:      // matchExpression
+        case symbol_kind::S_filterFields:         // filterFields
+        case symbol_kind::S_filterVal:            // filterVal
+        case symbol_kind::S_sortSpecs:            // sortSpecs
+        case symbol_kind::S_specList:             // specList
+        case symbol_kind::S_metaSort:             // metaSort
+        case symbol_kind::S_oneOrNegOne:          // oneOrNegOne
+        case symbol_kind::S_metaSortKeyword:      // metaSortKeyword
             value.copy<CNode>(that.value);
             break;
 
-        case 122:  // projectionFieldname
-        case 123:  // expressionFieldname
-        case 124:  // stageAsUserFieldname
-        case 125:  // filterFieldname
-        case 126:  // argAsUserFieldname
-        case 127:  // aggExprAsUserFieldname
-        case 128:  // invariableUserFieldname
-        case 129:  // idAsUserFieldname
-        case 130:  // valueFieldname
+        case symbol_kind::S_projectionFieldname:      // projectionFieldname
+        case symbol_kind::S_expressionFieldname:      // expressionFieldname
+        case symbol_kind::S_stageAsUserFieldname:     // stageAsUserFieldname
+        case symbol_kind::S_filterFieldname:          // filterFieldname
+        case symbol_kind::S_argAsUserFieldname:       // argAsUserFieldname
+        case symbol_kind::S_aggExprAsUserFieldname:   // aggExprAsUserFieldname
+        case symbol_kind::S_invariableUserFieldname:  // invariableUserFieldname
+        case symbol_kind::S_idAsUserFieldname:        // idAsUserFieldname
+        case symbol_kind::S_valueFieldname:           // valueFieldname
             value.copy<CNode::Fieldname>(that.value);
             break;
 
-        case 102:  // "Date"
+        case symbol_kind::S_DATE_LITERAL:  // "Date"
             value.copy<Date_t>(that.value);
             break;
 
-        case 112:  // "non-zero decimal"
+        case symbol_kind::S_DECIMAL_OTHER:  // "arbitrary decimal"
             value.copy<Decimal128>(that.value);
             break;
 
-        case 101:  // "ObjectID"
+        case symbol_kind::S_OBJECT_ID:  // "ObjectID"
             value.copy<OID>(that.value);
             break;
 
-        case 113:  // "Timestamp"
+        case symbol_kind::S_TIMESTAMP:  // "Timestamp"
             value.copy<Timestamp>(that.value);
             break;
 
-        case 115:  // "maxKey"
+        case symbol_kind::S_MAX_KEY:  // "maxKey"
             value.copy<UserMaxKey>(that.value);
             break;
 
-        case 114:  // "minKey"
+        case symbol_kind::S_MIN_KEY:  // "minKey"
             value.copy<UserMinKey>(that.value);
             break;
 
-        case 103:  // "null"
+        case symbol_kind::S_JSNULL:  // "null"
             value.copy<UserNull>(that.value);
             break;
 
-        case 100:  // "undefined"
+        case symbol_kind::S_UNDEFINED:  // "undefined"
             value.copy<UserUndefined>(that.value);
             break;
 
-        case 111:  // "non-zero double"
+        case symbol_kind::S_DOUBLE_OTHER:  // "arbitrary double"
             value.copy<double>(that.value);
             break;
 
-        case 109:  // "non-zero integer"
+        case symbol_kind::S_INT_OTHER:  // "arbitrary integer"
             value.copy<int>(that.value);
             break;
 
-        case 110:  // "non-zero long"
+        case symbol_kind::S_LONG_OTHER:  // "arbitrary long"
             value.copy<long long>(that.value);
             break;
 
-        case 131:  // projectField
-        case 132:  // expressionField
-        case 133:  // valueField
-        case 134:  // filterField
-        case 248:  // onErrorArg
-        case 249:  // onNullArg
-        case 250:  // formatArg
-        case 251:  // timezoneArg
-        case 252:  // charsArg
-        case 253:  // optionsArg
+        case symbol_kind::S_projectField:     // projectField
+        case symbol_kind::S_expressionField:  // expressionField
+        case symbol_kind::S_valueField:       // valueField
+        case symbol_kind::S_filterField:      // filterField
+        case symbol_kind::S_onErrorArg:       // onErrorArg
+        case symbol_kind::S_onNullArg:        // onNullArg
+        case symbol_kind::S_formatArg:        // formatArg
+        case symbol_kind::S_timezoneArg:      // timezoneArg
+        case symbol_kind::S_charsArg:         // charsArg
+        case symbol_kind::S_optionsArg:       // optionsArg
+        case symbol_kind::S_sortSpec:         // sortSpec
             value.copy<std::pair<CNode::Fieldname, CNode>>(that.value);
             break;
 
-        case 97:   // "fieldname"
-        case 98:   // "string"
-        case 116:  // "$-prefixed string"
-        case 117:  // "$$-prefixed string"
-        case 118:  // "$-prefixed fieldname"
+        case symbol_kind::S_FIELDNAME:              // "fieldname"
+        case symbol_kind::S_STRING:                 // "string"
+        case symbol_kind::S_DOLLAR_STRING:          // "$-prefixed string"
+        case symbol_kind::S_DOLLAR_DOLLAR_STRING:   // "$$-prefixed string"
+        case symbol_kind::S_DOLLAR_PREF_FIELDNAME:  // "$-prefixed fieldname"
             value.copy<std::string>(that.value);
             break;
 
-        case 254:  // expressions
-        case 255:  // values
-        case 256:  // exprZeroToTwo
+        case symbol_kind::S_expressions:    // expressions
+        case symbol_kind::S_values:         // values
+        case symbol_kind::S_exprZeroToTwo:  // exprZeroToTwo
             value.copy<std::vector<CNode>>(that.value);
             break;
 
@@ -955,230 +937,236 @@ PipelineParserGen::stack_symbol_type& PipelineParserGen::stack_symbol_type::oper
 PipelineParserGen::stack_symbol_type& PipelineParserGen::stack_symbol_type::operator=(
     stack_symbol_type& that) {
     state = that.state;
-    switch (that.type_get()) {
-        case 99:  // "BinData"
+    switch (that.kind()) {
+        case symbol_kind::S_BINARY:  // "BinData"
             value.move<BSONBinData>(that.value);
             break;
 
-        case 106:  // "Code"
+        case symbol_kind::S_JAVASCRIPT:  // "Code"
             value.move<BSONCode>(that.value);
             break;
 
-        case 108:  // "CodeWScope"
+        case symbol_kind::S_JAVASCRIPT_W_SCOPE:  // "CodeWScope"
             value.move<BSONCodeWScope>(that.value);
             break;
 
-        case 105:  // "dbPointer"
+        case symbol_kind::S_DB_POINTER:  // "dbPointer"
             value.move<BSONDBRef>(that.value);
             break;
 
-        case 104:  // "regex"
+        case symbol_kind::S_REGEX:  // "regex"
             value.move<BSONRegEx>(that.value);
             break;
 
-        case 107:  // "Symbol"
+        case symbol_kind::S_SYMBOL:  // "Symbol"
             value.move<BSONSymbol>(that.value);
             break;
 
-        case 135:  // dbPointer
-        case 136:  // javascript
-        case 137:  // symbol
-        case 138:  // javascriptWScope
-        case 139:  // int
-        case 140:  // timestamp
-        case 141:  // long
-        case 142:  // double
-        case 143:  // decimal
-        case 144:  // minKey
-        case 145:  // maxKey
-        case 146:  // value
-        case 147:  // string
-        case 148:  // fieldPath
-        case 149:  // binary
-        case 150:  // undefined
-        case 151:  // objectId
-        case 152:  // bool
-        case 153:  // date
-        case 154:  // null
-        case 155:  // regex
-        case 156:  // simpleValue
-        case 157:  // compoundValue
-        case 158:  // valueArray
-        case 159:  // valueObject
-        case 160:  // valueFields
-        case 161:  // variable
-        case 162:  // pipeline
-        case 163:  // stageList
-        case 164:  // stage
-        case 165:  // inhibitOptimization
-        case 166:  // unionWith
-        case 167:  // skip
-        case 168:  // limit
-        case 169:  // project
-        case 170:  // sample
-        case 171:  // projectFields
-        case 172:  // projection
-        case 173:  // num
-        case 174:  // expression
-        case 175:  // compoundExpression
-        case 176:  // exprFixedTwoArg
-        case 177:  // expressionArray
-        case 178:  // expressionObject
-        case 179:  // expressionFields
-        case 180:  // maths
-        case 181:  // add
-        case 182:  // atan2
-        case 183:  // boolExps
-        case 184:  // and
-        case 185:  // or
-        case 186:  // not
-        case 187:  // literalEscapes
-        case 188:  // const
-        case 189:  // literal
-        case 190:  // stringExps
-        case 191:  // concat
-        case 192:  // dateFromString
-        case 193:  // dateToString
-        case 194:  // indexOfBytes
-        case 195:  // indexOfCP
-        case 196:  // ltrim
-        case 197:  // regexFind
-        case 198:  // regexFindAll
-        case 199:  // regexMatch
-        case 200:  // regexArgs
-        case 201:  // replaceOne
-        case 202:  // replaceAll
-        case 203:  // rtrim
-        case 204:  // split
-        case 205:  // strLenBytes
-        case 206:  // strLenCP
-        case 207:  // strcasecmp
-        case 208:  // substr
-        case 209:  // substrBytes
-        case 210:  // substrCP
-        case 211:  // toLower
-        case 212:  // toUpper
-        case 213:  // trim
-        case 214:  // compExprs
-        case 215:  // cmp
-        case 216:  // eq
-        case 217:  // gt
-        case 218:  // gte
-        case 219:  // lt
-        case 220:  // lte
-        case 221:  // ne
-        case 222:  // typeExpression
-        case 223:  // convert
-        case 224:  // toBool
-        case 225:  // toDate
-        case 226:  // toDecimal
-        case 227:  // toDouble
-        case 228:  // toInt
-        case 229:  // toLong
-        case 230:  // toObjectId
-        case 231:  // toString
-        case 232:  // type
-        case 233:  // abs
-        case 234:  // ceil
-        case 235:  // divide
-        case 236:  // exponent
-        case 237:  // floor
-        case 238:  // ln
-        case 239:  // log
-        case 240:  // logten
-        case 241:  // mod
-        case 242:  // multiply
-        case 243:  // pow
-        case 244:  // round
-        case 245:  // sqrt
-        case 246:  // subtract
-        case 247:  // trunc
-        case 257:  // matchExpression
-        case 258:  // filterFields
-        case 259:  // filterVal
+        case symbol_kind::S_dbPointer:            // dbPointer
+        case symbol_kind::S_javascript:           // javascript
+        case symbol_kind::S_symbol:               // symbol
+        case symbol_kind::S_javascriptWScope:     // javascriptWScope
+        case symbol_kind::S_int:                  // int
+        case symbol_kind::S_timestamp:            // timestamp
+        case symbol_kind::S_long:                 // long
+        case symbol_kind::S_double:               // double
+        case symbol_kind::S_decimal:              // decimal
+        case symbol_kind::S_minKey:               // minKey
+        case symbol_kind::S_maxKey:               // maxKey
+        case symbol_kind::S_value:                // value
+        case symbol_kind::S_string:               // string
+        case symbol_kind::S_fieldPath:            // fieldPath
+        case symbol_kind::S_binary:               // binary
+        case symbol_kind::S_undefined:            // undefined
+        case symbol_kind::S_objectId:             // objectId
+        case symbol_kind::S_bool:                 // bool
+        case symbol_kind::S_date:                 // date
+        case symbol_kind::S_null:                 // null
+        case symbol_kind::S_regex:                // regex
+        case symbol_kind::S_simpleValue:          // simpleValue
+        case symbol_kind::S_compoundValue:        // compoundValue
+        case symbol_kind::S_valueArray:           // valueArray
+        case symbol_kind::S_valueObject:          // valueObject
+        case symbol_kind::S_valueFields:          // valueFields
+        case symbol_kind::S_variable:             // variable
+        case symbol_kind::S_pipeline:             // pipeline
+        case symbol_kind::S_stageList:            // stageList
+        case symbol_kind::S_stage:                // stage
+        case symbol_kind::S_inhibitOptimization:  // inhibitOptimization
+        case symbol_kind::S_unionWith:            // unionWith
+        case symbol_kind::S_skip:                 // skip
+        case symbol_kind::S_limit:                // limit
+        case symbol_kind::S_project:              // project
+        case symbol_kind::S_sample:               // sample
+        case symbol_kind::S_projectFields:        // projectFields
+        case symbol_kind::S_projection:           // projection
+        case symbol_kind::S_num:                  // num
+        case symbol_kind::S_expression:           // expression
+        case symbol_kind::S_compoundExpression:   // compoundExpression
+        case symbol_kind::S_exprFixedTwoArg:      // exprFixedTwoArg
+        case symbol_kind::S_expressionArray:      // expressionArray
+        case symbol_kind::S_expressionObject:     // expressionObject
+        case symbol_kind::S_expressionFields:     // expressionFields
+        case symbol_kind::S_maths:                // maths
+        case symbol_kind::S_add:                  // add
+        case symbol_kind::S_atan2:                // atan2
+        case symbol_kind::S_boolExps:             // boolExps
+        case symbol_kind::S_and:                  // and
+        case symbol_kind::S_or:                   // or
+        case symbol_kind::S_not:                  // not
+        case symbol_kind::S_literalEscapes:       // literalEscapes
+        case symbol_kind::S_const:                // const
+        case symbol_kind::S_literal:              // literal
+        case symbol_kind::S_stringExps:           // stringExps
+        case symbol_kind::S_concat:               // concat
+        case symbol_kind::S_dateFromString:       // dateFromString
+        case symbol_kind::S_dateToString:         // dateToString
+        case symbol_kind::S_indexOfBytes:         // indexOfBytes
+        case symbol_kind::S_indexOfCP:            // indexOfCP
+        case symbol_kind::S_ltrim:                // ltrim
+        case symbol_kind::S_regexFind:            // regexFind
+        case symbol_kind::S_regexFindAll:         // regexFindAll
+        case symbol_kind::S_regexMatch:           // regexMatch
+        case symbol_kind::S_regexArgs:            // regexArgs
+        case symbol_kind::S_replaceOne:           // replaceOne
+        case symbol_kind::S_replaceAll:           // replaceAll
+        case symbol_kind::S_rtrim:                // rtrim
+        case symbol_kind::S_split:                // split
+        case symbol_kind::S_strLenBytes:          // strLenBytes
+        case symbol_kind::S_strLenCP:             // strLenCP
+        case symbol_kind::S_strcasecmp:           // strcasecmp
+        case symbol_kind::S_substr:               // substr
+        case symbol_kind::S_substrBytes:          // substrBytes
+        case symbol_kind::S_substrCP:             // substrCP
+        case symbol_kind::S_toLower:              // toLower
+        case symbol_kind::S_toUpper:              // toUpper
+        case symbol_kind::S_trim:                 // trim
+        case symbol_kind::S_compExprs:            // compExprs
+        case symbol_kind::S_cmp:                  // cmp
+        case symbol_kind::S_eq:                   // eq
+        case symbol_kind::S_gt:                   // gt
+        case symbol_kind::S_gte:                  // gte
+        case symbol_kind::S_lt:                   // lt
+        case symbol_kind::S_lte:                  // lte
+        case symbol_kind::S_ne:                   // ne
+        case symbol_kind::S_typeExpression:       // typeExpression
+        case symbol_kind::S_convert:              // convert
+        case symbol_kind::S_toBool:               // toBool
+        case symbol_kind::S_toDate:               // toDate
+        case symbol_kind::S_toDecimal:            // toDecimal
+        case symbol_kind::S_toDouble:             // toDouble
+        case symbol_kind::S_toInt:                // toInt
+        case symbol_kind::S_toLong:               // toLong
+        case symbol_kind::S_toObjectId:           // toObjectId
+        case symbol_kind::S_toString:             // toString
+        case symbol_kind::S_type:                 // type
+        case symbol_kind::S_abs:                  // abs
+        case symbol_kind::S_ceil:                 // ceil
+        case symbol_kind::S_divide:               // divide
+        case symbol_kind::S_exponent:             // exponent
+        case symbol_kind::S_floor:                // floor
+        case symbol_kind::S_ln:                   // ln
+        case symbol_kind::S_log:                  // log
+        case symbol_kind::S_logten:               // logten
+        case symbol_kind::S_mod:                  // mod
+        case symbol_kind::S_multiply:             // multiply
+        case symbol_kind::S_pow:                  // pow
+        case symbol_kind::S_round:                // round
+        case symbol_kind::S_sqrt:                 // sqrt
+        case symbol_kind::S_subtract:             // subtract
+        case symbol_kind::S_trunc:                // trunc
+        case symbol_kind::S_matchExpression:      // matchExpression
+        case symbol_kind::S_filterFields:         // filterFields
+        case symbol_kind::S_filterVal:            // filterVal
+        case symbol_kind::S_sortSpecs:            // sortSpecs
+        case symbol_kind::S_specList:             // specList
+        case symbol_kind::S_metaSort:             // metaSort
+        case symbol_kind::S_oneOrNegOne:          // oneOrNegOne
+        case symbol_kind::S_metaSortKeyword:      // metaSortKeyword
             value.move<CNode>(that.value);
             break;
 
-        case 122:  // projectionFieldname
-        case 123:  // expressionFieldname
-        case 124:  // stageAsUserFieldname
-        case 125:  // filterFieldname
-        case 126:  // argAsUserFieldname
-        case 127:  // aggExprAsUserFieldname
-        case 128:  // invariableUserFieldname
-        case 129:  // idAsUserFieldname
-        case 130:  // valueFieldname
+        case symbol_kind::S_projectionFieldname:      // projectionFieldname
+        case symbol_kind::S_expressionFieldname:      // expressionFieldname
+        case symbol_kind::S_stageAsUserFieldname:     // stageAsUserFieldname
+        case symbol_kind::S_filterFieldname:          // filterFieldname
+        case symbol_kind::S_argAsUserFieldname:       // argAsUserFieldname
+        case symbol_kind::S_aggExprAsUserFieldname:   // aggExprAsUserFieldname
+        case symbol_kind::S_invariableUserFieldname:  // invariableUserFieldname
+        case symbol_kind::S_idAsUserFieldname:        // idAsUserFieldname
+        case symbol_kind::S_valueFieldname:           // valueFieldname
             value.move<CNode::Fieldname>(that.value);
             break;
 
-        case 102:  // "Date"
+        case symbol_kind::S_DATE_LITERAL:  // "Date"
             value.move<Date_t>(that.value);
             break;
 
-        case 112:  // "non-zero decimal"
+        case symbol_kind::S_DECIMAL_OTHER:  // "arbitrary decimal"
             value.move<Decimal128>(that.value);
             break;
 
-        case 101:  // "ObjectID"
+        case symbol_kind::S_OBJECT_ID:  // "ObjectID"
             value.move<OID>(that.value);
             break;
 
-        case 113:  // "Timestamp"
+        case symbol_kind::S_TIMESTAMP:  // "Timestamp"
             value.move<Timestamp>(that.value);
             break;
 
-        case 115:  // "maxKey"
+        case symbol_kind::S_MAX_KEY:  // "maxKey"
             value.move<UserMaxKey>(that.value);
             break;
 
-        case 114:  // "minKey"
+        case symbol_kind::S_MIN_KEY:  // "minKey"
             value.move<UserMinKey>(that.value);
             break;
 
-        case 103:  // "null"
+        case symbol_kind::S_JSNULL:  // "null"
             value.move<UserNull>(that.value);
             break;
 
-        case 100:  // "undefined"
+        case symbol_kind::S_UNDEFINED:  // "undefined"
             value.move<UserUndefined>(that.value);
             break;
 
-        case 111:  // "non-zero double"
+        case symbol_kind::S_DOUBLE_OTHER:  // "arbitrary double"
             value.move<double>(that.value);
             break;
 
-        case 109:  // "non-zero integer"
+        case symbol_kind::S_INT_OTHER:  // "arbitrary integer"
             value.move<int>(that.value);
             break;
 
-        case 110:  // "non-zero long"
+        case symbol_kind::S_LONG_OTHER:  // "arbitrary long"
             value.move<long long>(that.value);
             break;
 
-        case 131:  // projectField
-        case 132:  // expressionField
-        case 133:  // valueField
-        case 134:  // filterField
-        case 248:  // onErrorArg
-        case 249:  // onNullArg
-        case 250:  // formatArg
-        case 251:  // timezoneArg
-        case 252:  // charsArg
-        case 253:  // optionsArg
+        case symbol_kind::S_projectField:     // projectField
+        case symbol_kind::S_expressionField:  // expressionField
+        case symbol_kind::S_valueField:       // valueField
+        case symbol_kind::S_filterField:      // filterField
+        case symbol_kind::S_onErrorArg:       // onErrorArg
+        case symbol_kind::S_onNullArg:        // onNullArg
+        case symbol_kind::S_formatArg:        // formatArg
+        case symbol_kind::S_timezoneArg:      // timezoneArg
+        case symbol_kind::S_charsArg:         // charsArg
+        case symbol_kind::S_optionsArg:       // optionsArg
+        case symbol_kind::S_sortSpec:         // sortSpec
             value.move<std::pair<CNode::Fieldname, CNode>>(that.value);
             break;
 
-        case 97:   // "fieldname"
-        case 98:   // "string"
-        case 116:  // "$-prefixed string"
-        case 117:  // "$$-prefixed string"
-        case 118:  // "$-prefixed fieldname"
+        case symbol_kind::S_FIELDNAME:              // "fieldname"
+        case symbol_kind::S_STRING:                 // "string"
+        case symbol_kind::S_DOLLAR_STRING:          // "$-prefixed string"
+        case symbol_kind::S_DOLLAR_DOLLAR_STRING:   // "$$-prefixed string"
+        case symbol_kind::S_DOLLAR_PREF_FIELDNAME:  // "$-prefixed fieldname"
             value.move<std::string>(that.value);
             break;
 
-        case 254:  // expressions
-        case 255:  // values
-        case 256:  // exprZeroToTwo
+        case symbol_kind::S_expressions:    // expressions
+        case symbol_kind::S_values:         // values
+        case symbol_kind::S_exprZeroToTwo:  // exprZeroToTwo
             value.move<std::vector<CNode>>(that.value);
             break;
 
@@ -1204,18 +1192,15 @@ template <typename Base>
 void PipelineParserGen::yy_print_(std::ostream& yyo, const basic_symbol<Base>& yysym) const {
     std::ostream& yyoutput = yyo;
     YYUSE(yyoutput);
-    symbol_number_type yytype = yysym.type_get();
-#if defined __GNUC__ && !defined __clang__ && !defined __ICC && \
-    __GNUC__ * 100 + __GNUC_MINOR__ <= 408
-    // Avoid a (spurious) G++ 4.8 warning about "array subscript is
-    // below array bounds".
     if (yysym.empty())
-        std::abort();
-#endif
-    yyo << (yytype < yyntokens_ ? "token" : "nterm") << ' ' << yytname_[yytype] << " ("
-        << yysym.location << ": ";
-    YYUSE(yytype);
-    yyo << ')';
+        yyo << "empty symbol";
+    else {
+        symbol_kind_type yykind = yysym.kind();
+        yyo << (yykind < YYNTOKENS ? "token" : "nterm") << ' ' << yysym.name() << " ("
+            << yysym.location << ": ";
+        YYUSE(yykind);
+        yyo << ')';
+    }
 }
 #endif
 
@@ -1258,11 +1243,11 @@ void PipelineParserGen::set_debug_level(debug_level_type l) {
 #endif  // YYDEBUG
 
 PipelineParserGen::state_type PipelineParserGen::yy_lr_goto_state_(state_type yystate, int yysym) {
-    int yyr = yypgoto_[yysym - yyntokens_] + yystate;
+    int yyr = yypgoto_[yysym - YYNTOKENS] + yystate;
     if (0 <= yyr && yyr <= yylast_ && yycheck_[yyr] == yystate)
         return yytable_[yyr];
     else
-        return yydefgoto_[yysym - yyntokens_];
+        return yydefgoto_[yysym - YYNTOKENS];
 }
 
 bool PipelineParserGen::yy_pact_value_is_default_(int yyvalue) {
@@ -1314,6 +1299,7 @@ int PipelineParserGen::parse() {
     `-----------------------------------------------*/
     yynewstate:
         YYCDEBUG << "Entering state " << int(yystack_[0].state) << '\n';
+        YY_STACK_PRINT();
 
         // Accept?
         if (yystack_[0].state == yyfinal_)
@@ -1333,7 +1319,7 @@ int PipelineParserGen::parse() {
 
         // Read a lookahead token.
         if (yyla.empty()) {
-            YYCDEBUG << "Reading a token: ";
+            YYCDEBUG << "Reading a token\n";
 #if YY_EXCEPTIONS
             try
 #endif  // YY_EXCEPTIONS
@@ -1351,10 +1337,19 @@ int PipelineParserGen::parse() {
         }
         YY_SYMBOL_PRINT("Next token is", yyla);
 
+        if (yyla.kind() == symbol_kind::S_YYerror) {
+            // The scanner already issued an error message, process directly
+            // to error recovery.  But do not keep the error token as
+            // lookahead, it is too special and may lead us to an endless
+            // loop in error recovery. */
+            yyla.kind_ = symbol_kind::S_YYUNDEF;
+            goto yyerrlab1;
+        }
+
         /* If the proper action on seeing token YYLA.TYPE is to reduce or
            to detect an error, take that action.  */
-        yyn += yyla.type_get();
-        if (yyn < 0 || yylast_ < yyn || yycheck_[yyn] != yyla.type_get()) {
+        yyn += yyla.kind();
+        if (yyn < 0 || yylast_ < yyn || yycheck_[yyn] != yyla.kind()) {
             goto yydefault;
         }
 
@@ -1398,229 +1393,235 @@ int PipelineParserGen::parse() {
                correct type. The default '$$ = $1' action is NOT applied
                when using variants.  */
             switch (yyr1_[yyn]) {
-                case 99:  // "BinData"
+                case symbol_kind::S_BINARY:  // "BinData"
                     yylhs.value.emplace<BSONBinData>();
                     break;
 
-                case 106:  // "Code"
+                case symbol_kind::S_JAVASCRIPT:  // "Code"
                     yylhs.value.emplace<BSONCode>();
                     break;
 
-                case 108:  // "CodeWScope"
+                case symbol_kind::S_JAVASCRIPT_W_SCOPE:  // "CodeWScope"
                     yylhs.value.emplace<BSONCodeWScope>();
                     break;
 
-                case 105:  // "dbPointer"
+                case symbol_kind::S_DB_POINTER:  // "dbPointer"
                     yylhs.value.emplace<BSONDBRef>();
                     break;
 
-                case 104:  // "regex"
+                case symbol_kind::S_REGEX:  // "regex"
                     yylhs.value.emplace<BSONRegEx>();
                     break;
 
-                case 107:  // "Symbol"
+                case symbol_kind::S_SYMBOL:  // "Symbol"
                     yylhs.value.emplace<BSONSymbol>();
                     break;
 
-                case 135:  // dbPointer
-                case 136:  // javascript
-                case 137:  // symbol
-                case 138:  // javascriptWScope
-                case 139:  // int
-                case 140:  // timestamp
-                case 141:  // long
-                case 142:  // double
-                case 143:  // decimal
-                case 144:  // minKey
-                case 145:  // maxKey
-                case 146:  // value
-                case 147:  // string
-                case 148:  // fieldPath
-                case 149:  // binary
-                case 150:  // undefined
-                case 151:  // objectId
-                case 152:  // bool
-                case 153:  // date
-                case 154:  // null
-                case 155:  // regex
-                case 156:  // simpleValue
-                case 157:  // compoundValue
-                case 158:  // valueArray
-                case 159:  // valueObject
-                case 160:  // valueFields
-                case 161:  // variable
-                case 162:  // pipeline
-                case 163:  // stageList
-                case 164:  // stage
-                case 165:  // inhibitOptimization
-                case 166:  // unionWith
-                case 167:  // skip
-                case 168:  // limit
-                case 169:  // project
-                case 170:  // sample
-                case 171:  // projectFields
-                case 172:  // projection
-                case 173:  // num
-                case 174:  // expression
-                case 175:  // compoundExpression
-                case 176:  // exprFixedTwoArg
-                case 177:  // expressionArray
-                case 178:  // expressionObject
-                case 179:  // expressionFields
-                case 180:  // maths
-                case 181:  // add
-                case 182:  // atan2
-                case 183:  // boolExps
-                case 184:  // and
-                case 185:  // or
-                case 186:  // not
-                case 187:  // literalEscapes
-                case 188:  // const
-                case 189:  // literal
-                case 190:  // stringExps
-                case 191:  // concat
-                case 192:  // dateFromString
-                case 193:  // dateToString
-                case 194:  // indexOfBytes
-                case 195:  // indexOfCP
-                case 196:  // ltrim
-                case 197:  // regexFind
-                case 198:  // regexFindAll
-                case 199:  // regexMatch
-                case 200:  // regexArgs
-                case 201:  // replaceOne
-                case 202:  // replaceAll
-                case 203:  // rtrim
-                case 204:  // split
-                case 205:  // strLenBytes
-                case 206:  // strLenCP
-                case 207:  // strcasecmp
-                case 208:  // substr
-                case 209:  // substrBytes
-                case 210:  // substrCP
-                case 211:  // toLower
-                case 212:  // toUpper
-                case 213:  // trim
-                case 214:  // compExprs
-                case 215:  // cmp
-                case 216:  // eq
-                case 217:  // gt
-                case 218:  // gte
-                case 219:  // lt
-                case 220:  // lte
-                case 221:  // ne
-                case 222:  // typeExpression
-                case 223:  // convert
-                case 224:  // toBool
-                case 225:  // toDate
-                case 226:  // toDecimal
-                case 227:  // toDouble
-                case 228:  // toInt
-                case 229:  // toLong
-                case 230:  // toObjectId
-                case 231:  // toString
-                case 232:  // type
-                case 233:  // abs
-                case 234:  // ceil
-                case 235:  // divide
-                case 236:  // exponent
-                case 237:  // floor
-                case 238:  // ln
-                case 239:  // log
-                case 240:  // logten
-                case 241:  // mod
-                case 242:  // multiply
-                case 243:  // pow
-                case 244:  // round
-                case 245:  // sqrt
-                case 246:  // subtract
-                case 247:  // trunc
-                case 257:  // matchExpression
-                case 258:  // filterFields
-                case 259:  // filterVal
+                case symbol_kind::S_dbPointer:            // dbPointer
+                case symbol_kind::S_javascript:           // javascript
+                case symbol_kind::S_symbol:               // symbol
+                case symbol_kind::S_javascriptWScope:     // javascriptWScope
+                case symbol_kind::S_int:                  // int
+                case symbol_kind::S_timestamp:            // timestamp
+                case symbol_kind::S_long:                 // long
+                case symbol_kind::S_double:               // double
+                case symbol_kind::S_decimal:              // decimal
+                case symbol_kind::S_minKey:               // minKey
+                case symbol_kind::S_maxKey:               // maxKey
+                case symbol_kind::S_value:                // value
+                case symbol_kind::S_string:               // string
+                case symbol_kind::S_fieldPath:            // fieldPath
+                case symbol_kind::S_binary:               // binary
+                case symbol_kind::S_undefined:            // undefined
+                case symbol_kind::S_objectId:             // objectId
+                case symbol_kind::S_bool:                 // bool
+                case symbol_kind::S_date:                 // date
+                case symbol_kind::S_null:                 // null
+                case symbol_kind::S_regex:                // regex
+                case symbol_kind::S_simpleValue:          // simpleValue
+                case symbol_kind::S_compoundValue:        // compoundValue
+                case symbol_kind::S_valueArray:           // valueArray
+                case symbol_kind::S_valueObject:          // valueObject
+                case symbol_kind::S_valueFields:          // valueFields
+                case symbol_kind::S_variable:             // variable
+                case symbol_kind::S_pipeline:             // pipeline
+                case symbol_kind::S_stageList:            // stageList
+                case symbol_kind::S_stage:                // stage
+                case symbol_kind::S_inhibitOptimization:  // inhibitOptimization
+                case symbol_kind::S_unionWith:            // unionWith
+                case symbol_kind::S_skip:                 // skip
+                case symbol_kind::S_limit:                // limit
+                case symbol_kind::S_project:              // project
+                case symbol_kind::S_sample:               // sample
+                case symbol_kind::S_projectFields:        // projectFields
+                case symbol_kind::S_projection:           // projection
+                case symbol_kind::S_num:                  // num
+                case symbol_kind::S_expression:           // expression
+                case symbol_kind::S_compoundExpression:   // compoundExpression
+                case symbol_kind::S_exprFixedTwoArg:      // exprFixedTwoArg
+                case symbol_kind::S_expressionArray:      // expressionArray
+                case symbol_kind::S_expressionObject:     // expressionObject
+                case symbol_kind::S_expressionFields:     // expressionFields
+                case symbol_kind::S_maths:                // maths
+                case symbol_kind::S_add:                  // add
+                case symbol_kind::S_atan2:                // atan2
+                case symbol_kind::S_boolExps:             // boolExps
+                case symbol_kind::S_and:                  // and
+                case symbol_kind::S_or:                   // or
+                case symbol_kind::S_not:                  // not
+                case symbol_kind::S_literalEscapes:       // literalEscapes
+                case symbol_kind::S_const:                // const
+                case symbol_kind::S_literal:              // literal
+                case symbol_kind::S_stringExps:           // stringExps
+                case symbol_kind::S_concat:               // concat
+                case symbol_kind::S_dateFromString:       // dateFromString
+                case symbol_kind::S_dateToString:         // dateToString
+                case symbol_kind::S_indexOfBytes:         // indexOfBytes
+                case symbol_kind::S_indexOfCP:            // indexOfCP
+                case symbol_kind::S_ltrim:                // ltrim
+                case symbol_kind::S_regexFind:            // regexFind
+                case symbol_kind::S_regexFindAll:         // regexFindAll
+                case symbol_kind::S_regexMatch:           // regexMatch
+                case symbol_kind::S_regexArgs:            // regexArgs
+                case symbol_kind::S_replaceOne:           // replaceOne
+                case symbol_kind::S_replaceAll:           // replaceAll
+                case symbol_kind::S_rtrim:                // rtrim
+                case symbol_kind::S_split:                // split
+                case symbol_kind::S_strLenBytes:          // strLenBytes
+                case symbol_kind::S_strLenCP:             // strLenCP
+                case symbol_kind::S_strcasecmp:           // strcasecmp
+                case symbol_kind::S_substr:               // substr
+                case symbol_kind::S_substrBytes:          // substrBytes
+                case symbol_kind::S_substrCP:             // substrCP
+                case symbol_kind::S_toLower:              // toLower
+                case symbol_kind::S_toUpper:              // toUpper
+                case symbol_kind::S_trim:                 // trim
+                case symbol_kind::S_compExprs:            // compExprs
+                case symbol_kind::S_cmp:                  // cmp
+                case symbol_kind::S_eq:                   // eq
+                case symbol_kind::S_gt:                   // gt
+                case symbol_kind::S_gte:                  // gte
+                case symbol_kind::S_lt:                   // lt
+                case symbol_kind::S_lte:                  // lte
+                case symbol_kind::S_ne:                   // ne
+                case symbol_kind::S_typeExpression:       // typeExpression
+                case symbol_kind::S_convert:              // convert
+                case symbol_kind::S_toBool:               // toBool
+                case symbol_kind::S_toDate:               // toDate
+                case symbol_kind::S_toDecimal:            // toDecimal
+                case symbol_kind::S_toDouble:             // toDouble
+                case symbol_kind::S_toInt:                // toInt
+                case symbol_kind::S_toLong:               // toLong
+                case symbol_kind::S_toObjectId:           // toObjectId
+                case symbol_kind::S_toString:             // toString
+                case symbol_kind::S_type:                 // type
+                case symbol_kind::S_abs:                  // abs
+                case symbol_kind::S_ceil:                 // ceil
+                case symbol_kind::S_divide:               // divide
+                case symbol_kind::S_exponent:             // exponent
+                case symbol_kind::S_floor:                // floor
+                case symbol_kind::S_ln:                   // ln
+                case symbol_kind::S_log:                  // log
+                case symbol_kind::S_logten:               // logten
+                case symbol_kind::S_mod:                  // mod
+                case symbol_kind::S_multiply:             // multiply
+                case symbol_kind::S_pow:                  // pow
+                case symbol_kind::S_round:                // round
+                case symbol_kind::S_sqrt:                 // sqrt
+                case symbol_kind::S_subtract:             // subtract
+                case symbol_kind::S_trunc:                // trunc
+                case symbol_kind::S_matchExpression:      // matchExpression
+                case symbol_kind::S_filterFields:         // filterFields
+                case symbol_kind::S_filterVal:            // filterVal
+                case symbol_kind::S_sortSpecs:            // sortSpecs
+                case symbol_kind::S_specList:             // specList
+                case symbol_kind::S_metaSort:             // metaSort
+                case symbol_kind::S_oneOrNegOne:          // oneOrNegOne
+                case symbol_kind::S_metaSortKeyword:      // metaSortKeyword
                     yylhs.value.emplace<CNode>();
                     break;
 
-                case 122:  // projectionFieldname
-                case 123:  // expressionFieldname
-                case 124:  // stageAsUserFieldname
-                case 125:  // filterFieldname
-                case 126:  // argAsUserFieldname
-                case 127:  // aggExprAsUserFieldname
-                case 128:  // invariableUserFieldname
-                case 129:  // idAsUserFieldname
-                case 130:  // valueFieldname
+                case symbol_kind::S_projectionFieldname:      // projectionFieldname
+                case symbol_kind::S_expressionFieldname:      // expressionFieldname
+                case symbol_kind::S_stageAsUserFieldname:     // stageAsUserFieldname
+                case symbol_kind::S_filterFieldname:          // filterFieldname
+                case symbol_kind::S_argAsUserFieldname:       // argAsUserFieldname
+                case symbol_kind::S_aggExprAsUserFieldname:   // aggExprAsUserFieldname
+                case symbol_kind::S_invariableUserFieldname:  // invariableUserFieldname
+                case symbol_kind::S_idAsUserFieldname:        // idAsUserFieldname
+                case symbol_kind::S_valueFieldname:           // valueFieldname
                     yylhs.value.emplace<CNode::Fieldname>();
                     break;
 
-                case 102:  // "Date"
+                case symbol_kind::S_DATE_LITERAL:  // "Date"
                     yylhs.value.emplace<Date_t>();
                     break;
 
-                case 112:  // "non-zero decimal"
+                case symbol_kind::S_DECIMAL_OTHER:  // "arbitrary decimal"
                     yylhs.value.emplace<Decimal128>();
                     break;
 
-                case 101:  // "ObjectID"
+                case symbol_kind::S_OBJECT_ID:  // "ObjectID"
                     yylhs.value.emplace<OID>();
                     break;
 
-                case 113:  // "Timestamp"
+                case symbol_kind::S_TIMESTAMP:  // "Timestamp"
                     yylhs.value.emplace<Timestamp>();
                     break;
 
-                case 115:  // "maxKey"
+                case symbol_kind::S_MAX_KEY:  // "maxKey"
                     yylhs.value.emplace<UserMaxKey>();
                     break;
 
-                case 114:  // "minKey"
+                case symbol_kind::S_MIN_KEY:  // "minKey"
                     yylhs.value.emplace<UserMinKey>();
                     break;
 
-                case 103:  // "null"
+                case symbol_kind::S_JSNULL:  // "null"
                     yylhs.value.emplace<UserNull>();
                     break;
 
-                case 100:  // "undefined"
+                case symbol_kind::S_UNDEFINED:  // "undefined"
                     yylhs.value.emplace<UserUndefined>();
                     break;
 
-                case 111:  // "non-zero double"
+                case symbol_kind::S_DOUBLE_OTHER:  // "arbitrary double"
                     yylhs.value.emplace<double>();
                     break;
 
-                case 109:  // "non-zero integer"
+                case symbol_kind::S_INT_OTHER:  // "arbitrary integer"
                     yylhs.value.emplace<int>();
                     break;
 
-                case 110:  // "non-zero long"
+                case symbol_kind::S_LONG_OTHER:  // "arbitrary long"
                     yylhs.value.emplace<long long>();
                     break;
 
-                case 131:  // projectField
-                case 132:  // expressionField
-                case 133:  // valueField
-                case 134:  // filterField
-                case 248:  // onErrorArg
-                case 249:  // onNullArg
-                case 250:  // formatArg
-                case 251:  // timezoneArg
-                case 252:  // charsArg
-                case 253:  // optionsArg
+                case symbol_kind::S_projectField:     // projectField
+                case symbol_kind::S_expressionField:  // expressionField
+                case symbol_kind::S_valueField:       // valueField
+                case symbol_kind::S_filterField:      // filterField
+                case symbol_kind::S_onErrorArg:       // onErrorArg
+                case symbol_kind::S_onNullArg:        // onNullArg
+                case symbol_kind::S_formatArg:        // formatArg
+                case symbol_kind::S_timezoneArg:      // timezoneArg
+                case symbol_kind::S_charsArg:         // charsArg
+                case symbol_kind::S_optionsArg:       // optionsArg
+                case symbol_kind::S_sortSpec:         // sortSpec
                     yylhs.value.emplace<std::pair<CNode::Fieldname, CNode>>();
                     break;
 
-                case 97:   // "fieldname"
-                case 98:   // "string"
-                case 116:  // "$-prefixed string"
-                case 117:  // "$$-prefixed string"
-                case 118:  // "$-prefixed fieldname"
+                case symbol_kind::S_FIELDNAME:              // "fieldname"
+                case symbol_kind::S_STRING:                 // "string"
+                case symbol_kind::S_DOLLAR_STRING:          // "$-prefixed string"
+                case symbol_kind::S_DOLLAR_DOLLAR_STRING:   // "$$-prefixed string"
+                case symbol_kind::S_DOLLAR_PREF_FIELDNAME:  // "$-prefixed fieldname"
                     yylhs.value.emplace<std::string>();
                     break;
 
-                case 254:  // expressions
-                case 255:  // values
-                case 256:  // exprZeroToTwo
+                case symbol_kind::S_expressions:    // expressions
+                case symbol_kind::S_values:         // values
+                case symbol_kind::S_exprZeroToTwo:  // exprZeroToTwo
                     yylhs.value.emplace<std::vector<CNode>>();
                     break;
 
@@ -1643,106 +1644,114 @@ int PipelineParserGen::parse() {
 #endif  // YY_EXCEPTIONS
             {
                 switch (yyn) {
-                    case 2:
-#line 282 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 2:  // start: START_PIPELINE pipeline
+#line 297 "pipeline_grammar.yy"
                     {
                         invariant(cst);
                         *cst = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1720 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1719 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 3:
-#line 286 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 3:  // start: START_MATCH matchExpression
+#line 301 "pipeline_grammar.yy"
                     {
                         invariant(cst);
                         *cst = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1729 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1728 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 4:
-#line 294 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 4:  // start: START_SORT sortSpecs
+#line 305 "pipeline_grammar.yy"
+                    {
+                        *cst = CNode{YY_MOVE(yystack_[0].value.as<CNode>())};
+                    }
+#line 1736 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 5:  // pipeline: "array" stageList "end of array"
+#line 312 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[1].value.as<CNode>());
                     }
-#line 1737 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1744 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 5:
-#line 300 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 6:  // stageList: %empty
+#line 318 "pipeline_grammar.yy"
                     {
                     }
-#line 1743 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1750 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 6:
-#line 301 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 7:  // stageList: "object" stage "end of object" stageList
+#line 319 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{CNode::ArrayChildren{YY_MOVE(yystack_[2].value.as<CNode>())}};
                     }
-#line 1751 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1758 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 7:
-#line 309 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 8:  // $@1: %empty
+#line 327 "pipeline_grammar.yy"
                     {
                         lexer.sortObjTokens();
                     }
-#line 1757 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1764 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 9:
-#line 312 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 10:  // stage: inhibitOptimization
+#line 330 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1763 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1770 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 10:
-#line 312 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 11:  // stage: unionWith
+#line 330 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1769 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1776 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 11:
-#line 312 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 12:  // stage: skip
+#line 330 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1775 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1782 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 12:
-#line 312 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 13:  // stage: limit
+#line 330 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1781 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1788 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 13:
-#line 312 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 14:  // stage: project
+#line 330 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1787 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1794 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 14:
-#line 312 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 15:  // stage: sample
+#line 330 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1793 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1800 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 15:
-#line 315 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 16:  // sample: STAGE_SAMPLE "object" "size argument" num "end of object"
+#line 333 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{std::pair{
                             KeyFieldname::sample,
@@ -1750,20 +1759,22 @@ int PipelineParserGen::parse() {
                                 {KeyFieldname::sizeArg, YY_MOVE(yystack_[1].value.as<CNode>())},
                             }}}}};
                     }
-#line 1805 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1812 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 16:
-#line 325 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 17:  // inhibitOptimization: STAGE_INHIBIT_OPTIMIZATION "object" "end of
+                              // object"
+#line 343 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             std::pair{KeyFieldname::inhibitOptimization, CNode::noopLeaf()}}};
                     }
-#line 1813 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1820 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 17:
-#line 331 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 18:  // unionWith: STAGE_UNION_WITH START_ORDERED_OBJECT "coll argument"
+                              // string "pipeline argument" double "end of object"
+#line 349 "pipeline_grammar.yy"
                     {
                         auto pipeline = YY_MOVE(yystack_[1].value.as<CNode>());
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{std::pair{
@@ -1772,61 +1783,61 @@ int PipelineParserGen::parse() {
                                 {KeyFieldname::collArg, YY_MOVE(yystack_[3].value.as<CNode>())},
                                 {KeyFieldname::pipelineArg, std::move(pipeline)}}}}}};
                     }
-#line 1826 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1833 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 18:
-#line 341 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 19:  // num: int
+#line 359 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1832 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1839 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 19:
-#line 341 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 20:  // num: long
+#line 359 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1838 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1845 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 20:
-#line 341 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 21:  // num: double
+#line 359 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1844 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1851 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 21:
-#line 341 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 22:  // num: decimal
+#line 359 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1850 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1857 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 22:
-#line 345 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 23:  // skip: STAGE_SKIP num
+#line 363 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             std::pair{KeyFieldname::skip, YY_MOVE(yystack_[0].value.as<CNode>())}}};
                     }
-#line 1858 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1865 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 23:
-#line 350 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 24:  // limit: STAGE_LIMIT num
+#line 368 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{std::pair{
                             KeyFieldname::limit, YY_MOVE(yystack_[0].value.as<CNode>())}}};
                     }
-#line 1866 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1873 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 24:
-#line 355 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 25:  // project: STAGE_PROJECT "object" projectFields "end of object"
+#line 373 "pipeline_grammar.yy"
                     {
                         auto&& fields = YY_MOVE(yystack_[1].value.as<CNode>());
                         if (auto inclusion =
@@ -1842,244 +1853,308 @@ int PipelineParserGen::parse() {
                             // function.
                             error(yystack_[3].location, inclusion.getStatus().reason());
                     }
-#line 1884 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1891 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 25:
-#line 371 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 26:  // projectFields: %empty
+#line 389 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode::noopLeaf();
                     }
-#line 1892 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1899 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 26:
-#line 374 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 27:  // projectFields: projectFields projectField
+#line 392 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[1].value.as<CNode>());
                         yylhs.value.as<CNode>().objectChildren().emplace_back(
                             YY_MOVE(yystack_[0].value.as<std::pair<CNode::Fieldname, CNode>>()));
                     }
-#line 1901 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1908 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 27:
-#line 381 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 28:  // projectField: ID projection
+#line 399 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::pair<CNode::Fieldname, CNode>>() = {
                             KeyFieldname::id, YY_MOVE(yystack_[0].value.as<CNode>())};
                     }
-#line 1909 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1916 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 28:
-#line 384 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 29:  // projectField: projectionFieldname projection
+#line 402 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::pair<CNode::Fieldname, CNode>>() = {
                             YY_MOVE(yystack_[1].value.as<CNode::Fieldname>()),
                             YY_MOVE(yystack_[0].value.as<CNode>())};
                     }
-#line 1917 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1924 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 29:
-#line 390 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 30:  // projection: string
+#line 408 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1923 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1930 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 30:
-#line 391 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 31:  // projection: binary
+#line 409 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1929 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1936 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 31:
-#line 392 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 32:  // projection: undefined
+#line 410 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1935 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1942 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 32:
-#line 393 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 33:  // projection: objectId
+#line 411 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1941 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1948 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 33:
-#line 394 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 34:  // projection: date
+#line 412 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1947 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1954 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 34:
-#line 395 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 35:  // projection: null
+#line 413 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1953 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1960 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 35:
-#line 396 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 36:  // projection: regex
+#line 414 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1959 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1966 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 36:
-#line 397 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 37:  // projection: dbPointer
+#line 415 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1965 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1972 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 37:
-#line 398 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 38:  // projection: javascript
+#line 416 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1971 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1978 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 38:
-#line 399 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 39:  // projection: symbol
+#line 417 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1977 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1984 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 39:
-#line 400 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 40:  // projection: javascriptWScope
+#line 418 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 1983 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 1990 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 41:  // projection: "1 (int)"
+#line 419 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{NonZeroKey{1}};
+                    }
+#line 1998 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 42:  // projection: "-1 (int)"
+#line 422 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{NonZeroKey{-1}};
+                    }
+#line 2006 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 40:
-#line 401 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 43:  // projection: "arbitrary integer"
+#line 425 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{NonZeroKey{YY_MOVE(yystack_[0].value.as<int>())}};
                     }
-#line 1991 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2014 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 41:
-#line 404 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 44:  // projection: "zero (int)"
+#line 428 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{KeyValue::intZeroKey};
                     }
-#line 1999 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2022 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 42:
-#line 407 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 45:  // projection: "1 (long)"
+#line 431 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{NonZeroKey{1ll}};
+                    }
+#line 2030 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 46:  // projection: "-1 (long)"
+#line 434 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{NonZeroKey{-1ll}};
+                    }
+#line 2038 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 47:  // projection: "arbitrary long"
+#line 437 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{NonZeroKey{YY_MOVE(yystack_[0].value.as<long long>())}};
                     }
-#line 2007 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2046 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 43:
-#line 410 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 48:  // projection: "zero (long)"
+#line 440 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{KeyValue::longZeroKey};
                     }
-#line 2015 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2054 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 49:  // projection: "1 (double)"
+#line 443 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{NonZeroKey{1.0}};
+                    }
+#line 2062 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 50:  // projection: "-1 (double)"
+#line 446 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{NonZeroKey{-1.0}};
+                    }
+#line 2070 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 44:
-#line 413 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 51:  // projection: "arbitrary double"
+#line 449 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{NonZeroKey{YY_MOVE(yystack_[0].value.as<double>())}};
                     }
-#line 2023 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2078 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 45:
-#line 416 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 52:  // projection: "zero (double)"
+#line 452 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{KeyValue::doubleZeroKey};
                     }
-#line 2031 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2086 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 53:  // projection: "1 (decimal)"
+#line 455 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{NonZeroKey{1.0}};
+                    }
+#line 2094 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 54:  // projection: "-1 (decimal)"
+#line 458 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{NonZeroKey{-1.0}};
+                    }
+#line 2102 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 46:
-#line 419 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 55:  // projection: "arbitrary decimal"
+#line 461 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{NonZeroKey{YY_MOVE(yystack_[0].value.as<Decimal128>())}};
                     }
-#line 2039 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2110 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 47:
-#line 422 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 56:  // projection: "zero (decimal)"
+#line 464 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{KeyValue::decimalZeroKey};
                     }
-#line 2047 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2118 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 48:
-#line 425 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 57:  // projection: "true"
+#line 467 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{KeyValue::trueKey};
                     }
-#line 2055 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2126 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 49:
-#line 428 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 58:  // projection: "false"
+#line 470 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{KeyValue::falseKey};
                     }
-#line 2063 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2134 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 50:
-#line 431 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 59:  // projection: timestamp
+#line 473 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 2069 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2140 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 51:
-#line 432 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 60:  // projection: minKey
+#line 474 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 2075 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2146 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 52:
-#line 433 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 61:  // projection: maxKey
+#line 475 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 2081 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2152 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 53:
-#line 434 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 62:  // projection: compoundExpression
+#line 476 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             c_node_disambiguation::disambiguateCompoundProjection(
@@ -2091,801 +2166,825 @@ int PipelineParserGen::parse() {
                                       "object project field cannot contain both inclusion and "
                                       "exclusion indicators");
                     }
-#line 2092 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2163 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 54:
-#line 443 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 63:  // projectionFieldname: invariableUserFieldname
+#line 485 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() =
                             YY_MOVE(yystack_[0].value.as<CNode::Fieldname>());
                     }
-#line 2098 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2169 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 55:
-#line 443 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 64:  // projectionFieldname: stageAsUserFieldname
+#line 485 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() =
                             YY_MOVE(yystack_[0].value.as<CNode::Fieldname>());
                     }
-#line 2104 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2175 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 56:
-#line 443 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 65:  // projectionFieldname: argAsUserFieldname
+#line 485 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() =
                             YY_MOVE(yystack_[0].value.as<CNode::Fieldname>());
                     }
-#line 2110 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2181 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 57:
-#line 443 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 66:  // projectionFieldname: aggExprAsUserFieldname
+#line 485 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() =
                             YY_MOVE(yystack_[0].value.as<CNode::Fieldname>());
                     }
-#line 2116 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2187 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 58:
-#line 447 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 67:  // matchExpression: "object" filterFields "end of object"
+#line 489 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[1].value.as<CNode>());
                     }
-#line 2124 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2195 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 59:
-#line 453 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 68:  // filterFields: %empty
+#line 495 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode::noopLeaf();
                     }
-#line 2132 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2203 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 60:
-#line 456 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 69:  // filterFields: filterFields filterField
+#line 498 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[1].value.as<CNode>());
                         yylhs.value.as<CNode>().objectChildren().emplace_back(
                             YY_MOVE(yystack_[0].value.as<std::pair<CNode::Fieldname, CNode>>()));
                     }
-#line 2141 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2212 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 61:
-#line 462 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 70:  // filterField: filterFieldname filterVal
+#line 504 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::pair<CNode::Fieldname, CNode>>() = {
                             YY_MOVE(yystack_[1].value.as<CNode::Fieldname>()),
                             YY_MOVE(yystack_[0].value.as<CNode>())};
                     }
-#line 2149 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2220 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 62:
-#line 468 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 71:  // filterVal: value
+#line 510 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 2155 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2226 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 63:
-#line 473 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 72:  // filterFieldname: idAsUserFieldname
+#line 515 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() =
                             YY_MOVE(yystack_[0].value.as<CNode::Fieldname>());
                     }
-#line 2161 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2232 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 64:
-#line 473 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 73:  // filterFieldname: invariableUserFieldname
+#line 515 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() =
                             YY_MOVE(yystack_[0].value.as<CNode::Fieldname>());
                     }
-#line 2167 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2238 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 65:
-#line 473 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 74:  // filterFieldname: argAsUserFieldname
+#line 515 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() =
                             YY_MOVE(yystack_[0].value.as<CNode::Fieldname>());
                     }
-#line 2173 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2244 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 66:
-#line 477 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 75:  // invariableUserFieldname: "fieldname"
+#line 519 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() =
                             UserFieldname{YY_MOVE(yystack_[0].value.as<std::string>())};
                     }
-#line 2181 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2252 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 67:
-#line 485 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 76:  // stageAsUserFieldname: STAGE_INHIBIT_OPTIMIZATION
+#line 527 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() =
                             UserFieldname{"$_internalInhibitOptimization"};
                     }
-#line 2189 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2260 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 68:
-#line 488 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 77:  // stageAsUserFieldname: STAGE_UNION_WITH
+#line 530 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$unionWith"};
                     }
-#line 2197 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2268 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 69:
-#line 491 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 78:  // stageAsUserFieldname: STAGE_SKIP
+#line 533 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$skip"};
                     }
-#line 2205 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2276 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 70:
-#line 494 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 79:  // stageAsUserFieldname: STAGE_LIMIT
+#line 536 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$limit"};
                     }
-#line 2213 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2284 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 71:
-#line 497 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 80:  // stageAsUserFieldname: STAGE_PROJECT
+#line 539 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$project"};
                     }
-#line 2221 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2292 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 72:
-#line 500 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 81:  // stageAsUserFieldname: STAGE_SAMPLE
+#line 542 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$sample"};
                     }
-#line 2229 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2300 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 73:
-#line 509 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 82:  // argAsUserFieldname: "coll argument"
+#line 551 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"coll"};
                     }
-#line 2237 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2308 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 74:
-#line 512 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 83:  // argAsUserFieldname: "pipeline argument"
+#line 554 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"pipeline"};
                     }
-#line 2245 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2316 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 75:
-#line 515 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 84:  // argAsUserFieldname: "size argument"
+#line 557 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"size"};
                     }
-#line 2253 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2324 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 76:
-#line 518 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 85:  // argAsUserFieldname: "input argument"
+#line 560 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"input"};
                     }
-#line 2261 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2332 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 77:
-#line 521 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 86:  // argAsUserFieldname: "to argument"
+#line 563 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"to"};
                     }
-#line 2269 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2340 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 78:
-#line 524 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 87:  // argAsUserFieldname: "onError argument"
+#line 566 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"onError"};
                     }
-#line 2277 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2348 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 79:
-#line 527 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 88:  // argAsUserFieldname: "onNull argument"
+#line 569 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"onNull"};
                     }
-#line 2285 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2356 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 80:
-#line 530 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 89:  // argAsUserFieldname: "dateString argument"
+#line 572 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"dateString"};
                     }
-#line 2293 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2364 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 81:
-#line 533 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 90:  // argAsUserFieldname: "format argument"
+#line 575 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"format"};
                     }
-#line 2301 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2372 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 82:
-#line 536 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 91:  // argAsUserFieldname: "timezone argument"
+#line 578 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"timezone"};
                     }
-#line 2309 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2380 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 83:
-#line 539 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 92:  // argAsUserFieldname: "date argument"
+#line 581 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"date"};
                     }
-#line 2317 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2388 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 84:
-#line 542 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 93:  // argAsUserFieldname: "chars argument"
+#line 584 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"chars"};
                     }
-#line 2325 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2396 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 85:
-#line 545 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 94:  // argAsUserFieldname: "regex argument"
+#line 587 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"regex"};
                     }
-#line 2333 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2404 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 86:
-#line 548 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 95:  // argAsUserFieldname: "options argument"
+#line 590 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"options"};
                     }
-#line 2341 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2412 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 87:
-#line 551 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 96:  // argAsUserFieldname: "find argument"
+#line 593 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"find"};
                     }
-#line 2349 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2420 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 88:
-#line 554 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 97:  // argAsUserFieldname: "replacement argument"
+#line 596 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"replacement"};
                     }
-#line 2357 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2428 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 89:
-#line 562 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 98:  // aggExprAsUserFieldname: ADD
+#line 604 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$add"};
                     }
-#line 2365 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2436 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 90:
-#line 565 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 99:  // aggExprAsUserFieldname: ATAN2
+#line 607 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$atan2"};
                     }
-#line 2373 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2444 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 91:
-#line 568 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 100:  // aggExprAsUserFieldname: AND
+#line 610 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$and"};
                     }
-#line 2381 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2452 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 92:
-#line 571 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 101:  // aggExprAsUserFieldname: CONST_EXPR
+#line 613 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$const"};
                     }
-#line 2389 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2460 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 93:
-#line 574 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 102:  // aggExprAsUserFieldname: LITERAL
+#line 616 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$literal"};
                     }
-#line 2397 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2468 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 94:
-#line 577 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 103:  // aggExprAsUserFieldname: OR
+#line 619 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$or"};
                     }
-#line 2405 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2476 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 95:
-#line 580 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 104:  // aggExprAsUserFieldname: NOT
+#line 622 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$not"};
                     }
-#line 2413 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2484 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 96:
-#line 583 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 105:  // aggExprAsUserFieldname: CMP
+#line 625 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$cmp"};
                     }
-#line 2421 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2492 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 97:
-#line 586 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 106:  // aggExprAsUserFieldname: EQ
+#line 628 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$eq"};
                     }
-#line 2429 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2500 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 98:
-#line 589 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 107:  // aggExprAsUserFieldname: GT
+#line 631 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$gt"};
                     }
-#line 2437 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2508 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 99:
-#line 592 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 108:  // aggExprAsUserFieldname: GTE
+#line 634 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$gte"};
                     }
-#line 2445 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2516 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 100:
-#line 595 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 109:  // aggExprAsUserFieldname: LT
+#line 637 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$lt"};
                     }
-#line 2453 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2524 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 101:
-#line 598 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 110:  // aggExprAsUserFieldname: LTE
+#line 640 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$lte"};
                     }
-#line 2461 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2532 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 102:
-#line 601 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 111:  // aggExprAsUserFieldname: NE
+#line 643 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$ne"};
                     }
-#line 2469 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2540 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 103:
-#line 604 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 112:  // aggExprAsUserFieldname: CONVERT
+#line 646 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$convert"};
                     }
-#line 2477 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2548 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 104:
-#line 607 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 113:  // aggExprAsUserFieldname: TO_BOOL
+#line 649 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$toBool"};
                     }
-#line 2485 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2556 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 105:
-#line 610 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 114:  // aggExprAsUserFieldname: TO_DATE
+#line 652 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$toDate"};
                     }
-#line 2493 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2564 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 106:
-#line 613 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 115:  // aggExprAsUserFieldname: TO_DECIMAL
+#line 655 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$toDecimal"};
                     }
-#line 2501 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2572 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 107:
-#line 616 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 116:  // aggExprAsUserFieldname: TO_DOUBLE
+#line 658 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$toDouble"};
                     }
-#line 2509 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2580 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 108:
-#line 619 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 117:  // aggExprAsUserFieldname: TO_INT
+#line 661 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$toInt"};
                     }
-#line 2517 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2588 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 109:
-#line 622 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 118:  // aggExprAsUserFieldname: TO_LONG
+#line 664 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$toLong"};
                     }
-#line 2525 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2596 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 110:
-#line 625 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 119:  // aggExprAsUserFieldname: TO_OBJECT_ID
+#line 667 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$toObjectId"};
                     }
-#line 2533 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2604 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 111:
-#line 628 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 120:  // aggExprAsUserFieldname: TO_STRING
+#line 670 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$toString"};
                     }
-#line 2541 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2612 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 112:
-#line 631 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 121:  // aggExprAsUserFieldname: TYPE
+#line 673 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$type"};
                     }
-#line 2549 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2620 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 113:
-#line 634 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 122:  // aggExprAsUserFieldname: ABS
+#line 676 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$abs"};
                     }
-#line 2557 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2628 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 114:
-#line 637 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 123:  // aggExprAsUserFieldname: CEIL
+#line 679 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$ceil"};
                     }
-#line 2565 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2636 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 115:
-#line 640 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 124:  // aggExprAsUserFieldname: DIVIDE
+#line 682 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$divide"};
                     }
-#line 2573 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2644 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 116:
-#line 643 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 125:  // aggExprAsUserFieldname: EXPONENT
+#line 685 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$exp"};
                     }
-#line 2581 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2652 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 117:
-#line 646 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 126:  // aggExprAsUserFieldname: FLOOR
+#line 688 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$floor"};
                     }
-#line 2589 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2660 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 118:
-#line 649 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 127:  // aggExprAsUserFieldname: LN
+#line 691 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$ln"};
                     }
-#line 2597 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2668 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 119:
-#line 652 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 128:  // aggExprAsUserFieldname: LOG
+#line 694 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$log"};
                     }
-#line 2605 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2676 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 120:
-#line 655 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 129:  // aggExprAsUserFieldname: LOGTEN
+#line 697 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$log10"};
                     }
-#line 2613 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2684 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 121:
-#line 658 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 130:  // aggExprAsUserFieldname: MOD
+#line 700 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$mod"};
                     }
-#line 2621 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2692 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 122:
-#line 661 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 131:  // aggExprAsUserFieldname: MULTIPLY
+#line 703 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$multiply"};
                     }
-#line 2629 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2700 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 123:
-#line 664 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 132:  // aggExprAsUserFieldname: POW
+#line 706 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$pow"};
                     }
-#line 2637 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2708 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 124:
-#line 667 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 133:  // aggExprAsUserFieldname: ROUND
+#line 709 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$round"};
                     }
-#line 2645 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2716 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 125:
-#line 670 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 134:  // aggExprAsUserFieldname: SQRT
+#line 712 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$sqrt"};
                     }
-#line 2653 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2724 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 126:
-#line 673 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 135:  // aggExprAsUserFieldname: SUBTRACT
+#line 715 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$subtract"};
                     }
-#line 2661 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2732 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 127:
-#line 676 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 136:  // aggExprAsUserFieldname: TRUNC
+#line 718 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$trunc"};
                     }
-#line 2669 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2740 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 128:
-#line 679 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 137:  // aggExprAsUserFieldname: CONCAT
+#line 721 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$concat"};
                     }
-#line 2677 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2748 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 129:
-#line 682 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 138:  // aggExprAsUserFieldname: DATE_FROM_STRING
+#line 724 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$dateFromString"};
                     }
-#line 2685 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2756 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 130:
-#line 685 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 139:  // aggExprAsUserFieldname: DATE_TO_STRING
+#line 727 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$dateToString"};
                     }
-#line 2693 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2764 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 131:
-#line 688 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 140:  // aggExprAsUserFieldname: INDEX_OF_BYTES
+#line 730 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$indexOfBytes"};
                     }
-#line 2701 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2772 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 132:
-#line 691 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 141:  // aggExprAsUserFieldname: INDEX_OF_CP
+#line 733 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$indexOfCP"};
                     }
-#line 2709 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2780 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 133:
-#line 694 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 142:  // aggExprAsUserFieldname: LTRIM
+#line 736 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$ltrim"};
                     }
-#line 2717 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2788 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 143:  // aggExprAsUserFieldname: META
+#line 739 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$meta"};
+                    }
+#line 2796 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 134:
-#line 697 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 144:  // aggExprAsUserFieldname: REGEX_FIND
+#line 742 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$regexFind"};
                     }
-#line 2725 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2804 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 135:
-#line 700 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 145:  // aggExprAsUserFieldname: REGEX_FIND_ALL
+#line 745 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$regexFindAll"};
                     }
-#line 2733 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2812 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 136:
-#line 703 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 146:  // aggExprAsUserFieldname: REGEX_MATCH
+#line 748 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$regexMatch"};
                     }
-#line 2741 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2820 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 137:
-#line 706 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 147:  // aggExprAsUserFieldname: REPLACE_ONE
+#line 751 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$replaceOne"};
                     }
-#line 2749 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2828 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 138:
-#line 709 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 148:  // aggExprAsUserFieldname: REPLACE_ALL
+#line 754 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$replaceAll"};
                     }
-#line 2757 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2836 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 139:
-#line 712 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 149:  // aggExprAsUserFieldname: RTRIM
+#line 757 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$rtrim"};
                     }
-#line 2765 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2844 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 140:
-#line 715 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 150:  // aggExprAsUserFieldname: SPLIT
+#line 760 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$split"};
                     }
-#line 2773 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2852 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 141:
-#line 718 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 151:  // aggExprAsUserFieldname: STR_LEN_BYTES
+#line 763 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$strLenBytes"};
                     }
-#line 2781 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2860 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 142:
-#line 721 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 152:  // aggExprAsUserFieldname: STR_LEN_CP
+#line 766 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$strLenCP"};
                     }
-#line 2789 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2868 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 143:
-#line 724 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 153:  // aggExprAsUserFieldname: STR_CASE_CMP
+#line 769 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$strcasecmp"};
                     }
-#line 2797 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2876 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 144:
-#line 727 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 154:  // aggExprAsUserFieldname: SUBSTR
+#line 772 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$substr"};
                     }
-#line 2805 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2884 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 145:
-#line 730 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 155:  // aggExprAsUserFieldname: SUBSTR_BYTES
+#line 775 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$substrBytes"};
                     }
-#line 2813 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2892 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 146:
-#line 733 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 156:  // aggExprAsUserFieldname: SUBSTR_CP
+#line 778 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$substrCP"};
                     }
-#line 2821 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2900 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 147:
-#line 736 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 157:  // aggExprAsUserFieldname: TO_LOWER
+#line 781 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$toLower"};
                     }
-#line 2829 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2908 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 148:
-#line 739 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 158:  // aggExprAsUserFieldname: TRIM
+#line 784 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$trim"};
                     }
-#line 2837 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2916 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 149:
-#line 742 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 159:  // aggExprAsUserFieldname: TO_UPPER
+#line 787 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"$toUpper"};
                     }
-#line 2845 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2924 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 150:
-#line 749 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 160:  // string: "string"
+#line 794 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{UserString{YY_MOVE(yystack_[0].value.as<std::string>())}};
                     }
-#line 2853 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2932 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 161:  // string: "randVal"
+#line 799 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{UserString{"randVal"}};
+                    }
+#line 2940 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 151:
-#line 754 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 162:  // string: "textScore"
+#line 802 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{UserString{"textScore"}};
+                    }
+#line 2948 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 163:  // fieldPath: "$-prefixed string"
+#line 808 "pipeline_grammar.yy"
                     {
                         std::string str = YY_MOVE(yystack_[0].value.as<std::string>());
                         if (str.size() == 1) {
@@ -2893,11 +2992,11 @@ int PipelineParserGen::parse() {
                         }
                         yylhs.value.as<CNode>() = CNode{UserFieldPath{str.substr(1), false}};
                     }
-#line 2865 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2960 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 152:
-#line 762 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 164:  // variable: "$$-prefixed string"
+#line 816 "pipeline_grammar.yy"
                     {
                         std::string str = YY_MOVE(yystack_[0].value.as<std::string>()).substr(2);
                         auto status = c_node_validation::validateVariableName(str);
@@ -2906,815 +3005,883 @@ int PipelineParserGen::parse() {
                         }
                         yylhs.value.as<CNode>() = CNode{UserFieldPath{str, true}};
                     }
-#line 2878 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2973 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 153:
-#line 771 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 165:  // binary: "BinData"
+#line 825 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{UserBinary{YY_MOVE(yystack_[0].value.as<BSONBinData>())}};
                     }
-#line 2886 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2981 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 154:
-#line 777 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 166:  // undefined: "undefined"
+#line 831 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{UserUndefined{}};
                     }
-#line 2894 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2989 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 155:
-#line 783 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 167:  // objectId: "ObjectID"
+#line 837 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{UserObjectId{}};
                     }
-#line 2902 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 2997 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 156:
-#line 789 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 168:  // date: "Date"
+#line 843 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{UserDate{YY_MOVE(yystack_[0].value.as<Date_t>())}};
                     }
-#line 2910 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3005 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 157:
-#line 795 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 169:  // null: "null"
+#line 849 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{UserNull{}};
                     }
-#line 2918 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3013 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 158:
-#line 801 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 170:  // regex: "regex"
+#line 855 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{UserRegex{YY_MOVE(yystack_[0].value.as<BSONRegEx>())}};
                     }
-#line 2926 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3021 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 159:
-#line 807 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 171:  // dbPointer: "dbPointer"
+#line 861 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{UserDBPointer{YY_MOVE(yystack_[0].value.as<BSONDBRef>())}};
                     }
-#line 2934 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3029 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 160:
-#line 813 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 172:  // javascript: "Code"
+#line 867 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{UserJavascript{YY_MOVE(yystack_[0].value.as<BSONCode>())}};
                     }
-#line 2942 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3037 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 161:
-#line 819 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 173:  // symbol: "Symbol"
+#line 873 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{UserSymbol{YY_MOVE(yystack_[0].value.as<BSONSymbol>())}};
                     }
-#line 2950 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3045 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 162:
-#line 825 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 174:  // javascriptWScope: "CodeWScope"
+#line 879 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{UserJavascriptWithScope{
                             YY_MOVE(yystack_[0].value.as<BSONCodeWScope>())}};
                     }
-#line 2958 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3053 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 163:
-#line 831 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 175:  // timestamp: "Timestamp"
+#line 885 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{UserTimestamp{YY_MOVE(yystack_[0].value.as<Timestamp>())}};
                     }
-#line 2966 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3061 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 164:
-#line 837 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 176:  // minKey: "minKey"
+#line 891 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{UserMinKey{YY_MOVE(yystack_[0].value.as<UserMinKey>())}};
                     }
-#line 2974 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3069 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 165:
-#line 843 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 177:  // maxKey: "maxKey"
+#line 897 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{UserMaxKey{YY_MOVE(yystack_[0].value.as<UserMaxKey>())}};
                     }
-#line 2982 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3077 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 166:
-#line 849 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 178:  // int: "arbitrary integer"
+#line 903 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{UserInt{YY_MOVE(yystack_[0].value.as<int>())}};
                     }
-#line 2990 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3085 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 167:
-#line 852 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 179:  // int: "zero (int)"
+#line 906 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{UserInt{0}};
                     }
-#line 2998 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3093 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 168:
-#line 858 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 180:  // int: "1 (int)"
+#line 909 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{UserInt{1}};
+                    }
+#line 3101 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 181:  // int: "-1 (int)"
+#line 912 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{UserInt{-1}};
+                    }
+#line 3109 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 182:  // long: "arbitrary long"
+#line 918 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{UserLong{YY_MOVE(yystack_[0].value.as<long long>())}};
                     }
-#line 3006 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3117 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 169:
-#line 861 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 183:  // long: "zero (long)"
+#line 921 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{UserLong{0ll}};
                     }
-#line 3014 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3125 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 184:  // long: "1 (long)"
+#line 924 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{UserLong{1ll}};
+                    }
+#line 3133 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 170:
-#line 867 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 185:  // long: "-1 (long)"
+#line 927 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{UserLong{-1ll}};
+                    }
+#line 3141 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 186:  // double: "arbitrary double"
+#line 933 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{UserDouble{YY_MOVE(yystack_[0].value.as<double>())}};
                     }
-#line 3022 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3149 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 171:
-#line 870 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 187:  // double: "zero (double)"
+#line 936 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{UserDouble{0.0}};
                     }
-#line 3030 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3157 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 172:
-#line 876 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 188:  // double: "1 (double)"
+#line 939 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{UserDouble{1.0}};
+                    }
+#line 3165 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 189:  // double: "-1 (double)"
+#line 942 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{UserDouble{-1.0}};
+                    }
+#line 3173 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 190:  // decimal: "arbitrary decimal"
+#line 948 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{UserDecimal{YY_MOVE(yystack_[0].value.as<Decimal128>())}};
                     }
-#line 3038 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3181 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 173:
-#line 879 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 191:  // decimal: "zero (decimal)"
+#line 951 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{UserDecimal{0.0}};
                     }
-#line 3046 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3189 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 192:  // decimal: "1 (decimal)"
+#line 954 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{UserDecimal{1.0}};
+                    }
+#line 3197 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 193:  // decimal: "-1 (decimal)"
+#line 957 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{UserDecimal{-1.0}};
+                    }
+#line 3205 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 174:
-#line 885 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 194:  // bool: "true"
+#line 963 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{UserBoolean{true}};
                     }
-#line 3054 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3213 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 175:
-#line 888 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 195:  // bool: "false"
+#line 966 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{UserBoolean{false}};
                     }
-#line 3062 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3221 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 176:
-#line 894 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 196:  // simpleValue: string
+#line 972 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3068 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3227 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 177:
-#line 895 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 197:  // simpleValue: fieldPath
+#line 973 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3074 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3233 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 178:
-#line 896 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 198:  // simpleValue: variable
+#line 974 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3080 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3239 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 179:
-#line 897 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 199:  // simpleValue: binary
+#line 975 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3086 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3245 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 180:
-#line 898 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 200:  // simpleValue: undefined
+#line 976 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3092 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3251 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 181:
-#line 899 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 201:  // simpleValue: objectId
+#line 977 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3098 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3257 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 182:
-#line 900 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 202:  // simpleValue: date
+#line 978 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3104 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3263 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 183:
-#line 901 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 203:  // simpleValue: null
+#line 979 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3110 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3269 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 184:
-#line 902 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 204:  // simpleValue: regex
+#line 980 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3116 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3275 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 185:
-#line 903 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 205:  // simpleValue: dbPointer
+#line 981 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3122 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3281 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 186:
-#line 904 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 206:  // simpleValue: javascript
+#line 982 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3128 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3287 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 187:
-#line 905 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 207:  // simpleValue: symbol
+#line 983 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3134 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3293 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 188:
-#line 906 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 208:  // simpleValue: javascriptWScope
+#line 984 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3140 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3299 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 189:
-#line 907 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 209:  // simpleValue: int
+#line 985 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3146 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3305 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 190:
-#line 908 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 210:  // simpleValue: long
+#line 986 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3152 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3311 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 191:
-#line 909 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 211:  // simpleValue: double
+#line 987 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3158 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3317 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 192:
-#line 910 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 212:  // simpleValue: decimal
+#line 988 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3164 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3323 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 193:
-#line 911 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 213:  // simpleValue: bool
+#line 989 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3170 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3329 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 194:
-#line 912 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 214:  // simpleValue: timestamp
+#line 990 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3176 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3335 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 195:
-#line 913 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 215:  // simpleValue: minKey
+#line 991 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3182 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3341 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 196:
-#line 914 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 216:  // simpleValue: maxKey
+#line 992 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3188 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3347 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 197:
-#line 921 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 217:  // expressions: %empty
+#line 999 "pipeline_grammar.yy"
                     {
                     }
-#line 3194 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3353 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 198:
-#line 922 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 218:  // expressions: expression expressions
+#line 1000 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::vector<CNode>>() =
                             YY_MOVE(yystack_[0].value.as<std::vector<CNode>>());
                         yylhs.value.as<std::vector<CNode>>().emplace_back(
                             YY_MOVE(yystack_[1].value.as<CNode>()));
                     }
-#line 3203 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3362 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 199:
-#line 929 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 219:  // expression: simpleValue
+#line 1007 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3209 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3368 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 200:
-#line 929 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 220:  // expression: compoundExpression
+#line 1007 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3215 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3374 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 201:
-#line 933 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 221:  // exprFixedTwoArg: "array" expression expression "end of array"
+#line 1011 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{CNode::ArrayChildren{YY_MOVE(yystack_[2].value.as<CNode>()),
                                                        YY_MOVE(yystack_[1].value.as<CNode>())}};
                     }
-#line 3223 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3382 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 202:
-#line 938 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 222:  // compoundExpression: expressionArray
+#line 1016 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3229 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3388 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 203:
-#line 938 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 223:  // compoundExpression: expressionObject
+#line 1016 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3235 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3394 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 204:
-#line 938 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 224:  // compoundExpression: maths
+#line 1016 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3241 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3400 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 205:
-#line 938 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 225:  // compoundExpression: boolExps
+#line 1016 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3247 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3406 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 206:
-#line 938 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 226:  // compoundExpression: literalEscapes
+#line 1016 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3253 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3412 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 207:
-#line 938 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 227:  // compoundExpression: compExprs
+#line 1016 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3259 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3418 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 208:
-#line 939 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 228:  // compoundExpression: typeExpression
+#line 1017 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3265 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3424 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 209:
-#line 939 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 229:  // compoundExpression: stringExps
+#line 1017 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3271 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3430 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 210:
-#line 945 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 230:  // expressionArray: "array" expressions "end of array"
+#line 1023 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{YY_MOVE(yystack_[1].value.as<std::vector<CNode>>())};
                     }
-#line 3279 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3438 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 211:
-#line 953 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 231:  // expressionObject: "object" expressionFields "end of object"
+#line 1031 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[1].value.as<CNode>());
                     }
-#line 3287 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3446 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 212:
-#line 959 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 232:  // expressionFields: %empty
+#line 1037 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode::noopLeaf();
                     }
-#line 3295 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3454 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 213:
-#line 962 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 233:  // expressionFields: expressionFields expressionField
+#line 1040 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[1].value.as<CNode>());
                         yylhs.value.as<CNode>().objectChildren().emplace_back(
                             YY_MOVE(yystack_[0].value.as<std::pair<CNode::Fieldname, CNode>>()));
                     }
-#line 3304 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3463 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 214:
-#line 969 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 234:  // expressionField: expressionFieldname expression
+#line 1047 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::pair<CNode::Fieldname, CNode>>() = {
                             YY_MOVE(yystack_[1].value.as<CNode::Fieldname>()),
                             YY_MOVE(yystack_[0].value.as<CNode>())};
                     }
-#line 3312 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3471 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 215:
-#line 976 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 235:  // expressionFieldname: invariableUserFieldname
+#line 1054 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() =
                             YY_MOVE(yystack_[0].value.as<CNode::Fieldname>());
                     }
-#line 3318 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3477 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 216:
-#line 976 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 236:  // expressionFieldname: stageAsUserFieldname
+#line 1054 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() =
                             YY_MOVE(yystack_[0].value.as<CNode::Fieldname>());
                     }
-#line 3324 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3483 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 217:
-#line 976 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 237:  // expressionFieldname: argAsUserFieldname
+#line 1054 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() =
                             YY_MOVE(yystack_[0].value.as<CNode::Fieldname>());
                     }
-#line 3330 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3489 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 218:
-#line 976 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 238:  // expressionFieldname: idAsUserFieldname
+#line 1054 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() =
                             YY_MOVE(yystack_[0].value.as<CNode::Fieldname>());
                     }
-#line 3336 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3495 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 219:
-#line 980 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 239:  // idAsUserFieldname: ID
+#line 1058 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() = UserFieldname{"_id"};
                     }
-#line 3344 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3503 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 220:
-#line 986 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 240:  // maths: add
+#line 1064 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3350 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3509 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 221:
-#line 986 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 241:  // maths: atan2
+#line 1064 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3356 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3515 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 222:
-#line 986 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 242:  // maths: abs
+#line 1064 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3362 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3521 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 223:
-#line 986 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 243:  // maths: ceil
+#line 1064 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3368 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3527 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 224:
-#line 986 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 244:  // maths: divide
+#line 1064 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3374 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3533 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 225:
-#line 986 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 245:  // maths: exponent
+#line 1064 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3380 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3539 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 226:
-#line 986 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 246:  // maths: floor
+#line 1064 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3386 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3545 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 227:
-#line 986 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 247:  // maths: ln
+#line 1064 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3392 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3551 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 228:
-#line 986 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 248:  // maths: log
+#line 1064 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3398 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3557 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 229:
-#line 986 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 249:  // maths: logten
+#line 1064 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3404 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3563 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 230:
-#line 986 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 250:  // maths: mod
+#line 1064 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3410 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3569 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 231:
-#line 986 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 251:  // maths: multiply
+#line 1064 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3416 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3575 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 232:
-#line 986 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 252:  // maths: pow
+#line 1064 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3422 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3581 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 233:
-#line 987 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 253:  // maths: round
+#line 1065 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3428 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3587 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 234:
-#line 987 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 254:  // maths: sqrt
+#line 1065 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3434 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3593 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 235:
-#line 987 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 255:  // maths: subtract
+#line 1065 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3440 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3599 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 236:
-#line 987 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 256:  // maths: trunc
+#line 1065 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3446 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3605 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 237:
-#line 991 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 257:  // add: "object" ADD expressionArray "end of object"
+#line 1069 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::add, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 3455 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3614 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 238:
-#line 998 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 258:  // atan2: "object" ATAN2 exprFixedTwoArg "end of object"
+#line 1076 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::atan2, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 3464 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3623 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 239:
-#line 1004 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 259:  // abs: "object" ABS expression "end of object"
+#line 1082 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::abs, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 3472 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3631 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 240:
-#line 1009 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 260:  // ceil: "object" CEIL expression "end of object"
+#line 1087 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::ceil, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 3480 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3639 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 241:
-#line 1014 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 261:  // divide: "object" DIVIDE "array" expression expression "end of
+                               // array" "end of object"
+#line 1092 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::divide,
                              CNode{CNode::ArrayChildren{YY_MOVE(yystack_[3].value.as<CNode>()),
                                                         YY_MOVE(yystack_[2].value.as<CNode>())}}}}};
                     }
-#line 3489 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3648 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 242:
-#line 1020 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 262:  // exponent: "object" EXPONENT expression "end of object"
+#line 1098 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::exponent, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 3497 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3656 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 243:
-#line 1025 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 263:  // floor: "object" FLOOR expression "end of object"
+#line 1103 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::floor, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 3505 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3664 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 244:
-#line 1030 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 264:  // ln: "object" LN expression "end of object"
+#line 1108 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::ln, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 3513 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3672 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 245:
-#line 1035 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 265:  // log: "object" LOG "array" expression expression "end of array"
+                               // "end of object"
+#line 1113 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::log,
                              CNode{CNode::ArrayChildren{YY_MOVE(yystack_[3].value.as<CNode>()),
                                                         YY_MOVE(yystack_[2].value.as<CNode>())}}}}};
                     }
-#line 3522 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3681 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 246:
-#line 1041 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 266:  // logten: "object" LOGTEN expression "end of object"
+#line 1119 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::logten, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 3530 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3689 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 247:
-#line 1046 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 267:  // mod: "object" MOD "array" expression expression "end of array"
+                               // "end of object"
+#line 1124 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::mod,
                              CNode{CNode::ArrayChildren{YY_MOVE(yystack_[3].value.as<CNode>()),
                                                         YY_MOVE(yystack_[2].value.as<CNode>())}}}}};
                     }
-#line 3539 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3698 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 248:
-#line 1052 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 268:  // multiply: "object" MULTIPLY "array" expression expression
+                               // expressions "end of array" "end of object"
+#line 1130 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::multiply,
@@ -3725,292 +3892,298 @@ int PipelineParserGen::parse() {
                             yylhs.value.as<CNode>().objectChildren()[0].second.arrayChildren();
                         array.insert(array.end(), others.begin(), others.end());
                     }
-#line 3551 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3710 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 249:
-#line 1061 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 269:  // pow: "object" POW "array" expression expression "end of array"
+                               // "end of object"
+#line 1139 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::pow,
                              CNode{CNode::ArrayChildren{YY_MOVE(yystack_[3].value.as<CNode>()),
                                                         YY_MOVE(yystack_[2].value.as<CNode>())}}}}};
                     }
-#line 3560 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3719 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 250:
-#line 1067 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 270:  // round: "object" ROUND "array" expression expression "end of array"
+                               // "end of object"
+#line 1145 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::round,
                              CNode{CNode::ArrayChildren{YY_MOVE(yystack_[3].value.as<CNode>()),
                                                         YY_MOVE(yystack_[2].value.as<CNode>())}}}}};
                     }
-#line 3569 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3728 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 251:
-#line 1073 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 271:  // sqrt: "object" SQRT expression "end of object"
+#line 1151 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::sqrt, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 3577 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3736 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 252:
-#line 1078 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 272:  // subtract: "object" SUBTRACT "array" expression expression "end of
+                               // array" "end of object"
+#line 1156 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::subtract,
                              CNode{CNode::ArrayChildren{YY_MOVE(yystack_[3].value.as<CNode>()),
                                                         YY_MOVE(yystack_[2].value.as<CNode>())}}}}};
                     }
-#line 3586 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3745 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 253:
-#line 1084 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 273:  // trunc: "object" TRUNC "array" expression expression "end of array"
+                               // "end of object"
+#line 1162 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::trunc,
                              CNode{CNode::ArrayChildren{YY_MOVE(yystack_[3].value.as<CNode>()),
                                                         YY_MOVE(yystack_[2].value.as<CNode>())}}}}};
                     }
-#line 3595 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3754 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 254:
-#line 1090 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 274:  // boolExps: and
+#line 1168 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3601 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3760 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 255:
-#line 1090 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 275:  // boolExps: or
+#line 1168 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3607 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3766 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 256:
-#line 1090 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 276:  // boolExps: not
+#line 1168 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3613 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3772 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 257:
-#line 1094 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 277:  // and: "object" AND expressionArray "end of object"
+#line 1172 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::andExpr, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 3622 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3781 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 258:
-#line 1101 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 278:  // or: "object" OR expressionArray "end of object"
+#line 1179 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::orExpr, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 3631 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3790 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 259:
-#line 1108 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 279:  // not: "object" NOT "array" expression "end of array" "end of
+                               // object"
+#line 1186 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::notExpr,
                              CNode{CNode::ArrayChildren{YY_MOVE(yystack_[2].value.as<CNode>())}}}}};
                     }
-#line 3640 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3799 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 260:
-#line 1115 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 280:  // stringExps: concat
+#line 1193 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3646 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3805 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 261:
-#line 1115 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 281:  // stringExps: dateFromString
+#line 1193 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3652 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3811 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 262:
-#line 1115 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 282:  // stringExps: dateToString
+#line 1193 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3658 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3817 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 263:
-#line 1115 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 283:  // stringExps: indexOfBytes
+#line 1193 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3664 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3823 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 264:
-#line 1115 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 284:  // stringExps: indexOfCP
+#line 1193 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3670 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3829 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 265:
-#line 1115 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 285:  // stringExps: ltrim
+#line 1193 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3676 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3835 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 266:
-#line 1115 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 286:  // stringExps: regexFind
+#line 1193 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3682 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3841 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 267:
-#line 1116 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 287:  // stringExps: regexFindAll
+#line 1194 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3688 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3847 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 268:
-#line 1116 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 288:  // stringExps: regexMatch
+#line 1194 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3694 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3853 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 269:
-#line 1116 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 289:  // stringExps: replaceOne
+#line 1194 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3700 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3859 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 270:
-#line 1116 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 290:  // stringExps: replaceAll
+#line 1194 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3706 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3865 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 271:
-#line 1116 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 291:  // stringExps: rtrim
+#line 1194 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3712 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3871 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 272:
-#line 1116 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 292:  // stringExps: split
+#line 1194 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3718 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3877 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 273:
-#line 1116 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 293:  // stringExps: strLenBytes
+#line 1194 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3724 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3883 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 274:
-#line 1116 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 294:  // stringExps: strLenCP
+#line 1194 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3730 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3889 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 275:
-#line 1117 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 295:  // stringExps: strcasecmp
+#line 1195 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3736 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3895 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 276:
-#line 1117 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 296:  // stringExps: substr
+#line 1195 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3742 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3901 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 277:
-#line 1117 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 297:  // stringExps: substrBytes
+#line 1195 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3748 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3907 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 278:
-#line 1117 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 298:  // stringExps: substrCP
+#line 1195 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3754 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3913 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 279:
-#line 1117 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 299:  // stringExps: toLower
+#line 1195 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3760 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3919 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 280:
-#line 1117 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 300:  // stringExps: trim
+#line 1195 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3766 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3925 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 281:
-#line 1117 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 301:  // stringExps: toUpper
+#line 1195 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 3772 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3931 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 282:
-#line 1121 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 302:  // concat: "object" CONCAT "array" expressions "end of array" "end of
+                               // object"
+#line 1199 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::concat, CNode{CNode::ArrayChildren{}}}}};
@@ -4019,47 +4192,49 @@ int PipelineParserGen::parse() {
                             yylhs.value.as<CNode>().objectChildren()[0].second.arrayChildren();
                         array.insert(array.end(), others.begin(), others.end());
                     }
-#line 3784 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3943 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 283:
-#line 1131 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 303:  // formatArg: %empty
+#line 1209 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::pair<CNode::Fieldname, CNode>>() =
                             std::pair{KeyFieldname::formatArg, CNode{KeyValue::absentKey}};
                     }
-#line 3792 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3951 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 284:
-#line 1134 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 304:  // formatArg: "format argument" expression
+#line 1212 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::pair<CNode::Fieldname, CNode>>() = std::pair{
                             KeyFieldname::formatArg, YY_MOVE(yystack_[0].value.as<CNode>())};
                     }
-#line 3800 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3959 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 285:
-#line 1140 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 305:  // timezoneArg: %empty
+#line 1218 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::pair<CNode::Fieldname, CNode>>() =
                             std::pair{KeyFieldname::timezoneArg, CNode{KeyValue::absentKey}};
                     }
-#line 3808 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3967 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 286:
-#line 1143 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 306:  // timezoneArg: "timezone argument" expression
+#line 1221 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::pair<CNode::Fieldname, CNode>>() = std::pair{
                             KeyFieldname::timezoneArg, YY_MOVE(yystack_[0].value.as<CNode>())};
                     }
-#line 3816 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3975 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 287:
-#line 1150 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 307:  // dateFromString: "object" DATE_FROM_STRING START_ORDERED_OBJECT
+                               // "dateString argument" expression formatArg timezoneArg onErrorArg
+                               // onNullArg "end of object" "end of object"
+#line 1228 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::dateFromString,
@@ -4075,11 +4250,13 @@ int PipelineParserGen::parse() {
                                  YY_MOVE(yystack_[2]
                                              .value.as<std::pair<CNode::Fieldname, CNode>>())}}}}};
                     }
-#line 3826 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3985 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 288:
-#line 1159 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 308:  // dateToString: "object" DATE_TO_STRING START_ORDERED_OBJECT "date
+                               // argument" expression formatArg timezoneArg onNullArg "end of
+                               // object" "end of object"
+#line 1237 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::dateToString,
@@ -4092,38 +4269,39 @@ int PipelineParserGen::parse() {
                                  YY_MOVE(yystack_[2]
                                              .value.as<std::pair<CNode::Fieldname, CNode>>())}}}}};
                     }
-#line 3836 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 3995 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 289:
-#line 1167 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 309:  // exprZeroToTwo: %empty
+#line 1245 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::vector<CNode>>() = CNode::ArrayChildren{};
                     }
-#line 3844 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4003 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 290:
-#line 1170 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 310:  // exprZeroToTwo: expression
+#line 1248 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::vector<CNode>>() =
                             CNode::ArrayChildren{YY_MOVE(yystack_[0].value.as<CNode>())};
                     }
-#line 3852 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4011 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 291:
-#line 1173 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 311:  // exprZeroToTwo: expression expression
+#line 1251 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::vector<CNode>>() =
                             CNode::ArrayChildren{YY_MOVE(yystack_[1].value.as<CNode>()),
                                                  YY_MOVE(yystack_[0].value.as<CNode>())};
                     }
-#line 3860 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4019 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 292:
-#line 1180 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 312:  // indexOfBytes: "object" INDEX_OF_BYTES "array" expression
+                               // expression exprZeroToTwo "end of array" "end of object"
+#line 1258 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::indexOfBytes,
@@ -4134,11 +4312,12 @@ int PipelineParserGen::parse() {
                             yylhs.value.as<CNode>().objectChildren()[0].second.arrayChildren();
                         array.insert(array.end(), others.begin(), others.end());
                     }
-#line 3872 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4031 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 293:
-#line 1191 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 313:  // indexOfCP: "object" INDEX_OF_CP "array" expression expression
+                               // exprZeroToTwo "end of array" "end of object"
+#line 1269 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::indexOfCP,
@@ -4149,29 +4328,30 @@ int PipelineParserGen::parse() {
                             yylhs.value.as<CNode>().objectChildren()[0].second.arrayChildren();
                         array.insert(array.end(), others.begin(), others.end());
                     }
-#line 3884 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4043 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 294:
-#line 1201 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 314:  // charsArg: %empty
+#line 1279 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::pair<CNode::Fieldname, CNode>>() =
                             std::pair{KeyFieldname::charsArg, CNode{KeyValue::absentKey}};
                     }
-#line 3892 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4051 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 295:
-#line 1204 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 315:  // charsArg: "chars argument" expression
+#line 1282 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::pair<CNode::Fieldname, CNode>>() = std::pair{
                             KeyFieldname::charsArg, YY_MOVE(yystack_[0].value.as<CNode>())};
                     }
-#line 3900 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4059 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 296:
-#line 1210 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 316:  // ltrim: "object" LTRIM START_ORDERED_OBJECT charsArg "input
+                               // argument" expression "end of object" "end of object"
+#line 1288 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::ltrim,
@@ -4180,11 +4360,12 @@ int PipelineParserGen::parse() {
                                  YY_MOVE(yystack_[4]
                                              .value.as<std::pair<CNode::Fieldname, CNode>>())}}}}};
                     }
-#line 3910 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4069 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 297:
-#line 1218 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 317:  // rtrim: "object" RTRIM START_ORDERED_OBJECT charsArg "input
+                               // argument" expression "end of object" "end of object"
+#line 1296 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::rtrim,
@@ -4193,11 +4374,12 @@ int PipelineParserGen::parse() {
                                  YY_MOVE(yystack_[4]
                                              .value.as<std::pair<CNode::Fieldname, CNode>>())}}}}};
                     }
-#line 3920 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4079 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 298:
-#line 1226 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 318:  // trim: "object" TRIM START_ORDERED_OBJECT charsArg "input argument"
+                               // expression "end of object" "end of object"
+#line 1304 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::trim,
@@ -4206,29 +4388,30 @@ int PipelineParserGen::parse() {
                                  YY_MOVE(yystack_[4]
                                              .value.as<std::pair<CNode::Fieldname, CNode>>())}}}}};
                     }
-#line 3930 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4089 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 299:
-#line 1234 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 319:  // optionsArg: %empty
+#line 1312 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::pair<CNode::Fieldname, CNode>>() =
                             std::pair{KeyFieldname::optionsArg, CNode{KeyValue::absentKey}};
                     }
-#line 3938 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4097 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 300:
-#line 1237 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 320:  // optionsArg: "options argument" expression
+#line 1315 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::pair<CNode::Fieldname, CNode>>() = std::pair{
                             KeyFieldname::optionsArg, YY_MOVE(yystack_[0].value.as<CNode>())};
                     }
-#line 3946 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4105 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 301:
-#line 1242 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 321:  // regexArgs: START_ORDERED_OBJECT "input argument" expression
+                               // optionsArg "regex argument" expression "end of object"
+#line 1320 "pipeline_grammar.yy"
                     {
                         // Note that the order of these arguments must match the constructor for the
                         // regex expression.
@@ -4237,38 +4420,40 @@ int PipelineParserGen::parse() {
                             {KeyFieldname::regexArg, YY_MOVE(yystack_[1].value.as<CNode>())},
                             YY_MOVE(yystack_[3].value.as<std::pair<CNode::Fieldname, CNode>>())}};
                     }
-#line 3958 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4117 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 302:
-#line 1251 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 322:  // regexFind: "object" REGEX_FIND regexArgs "end of object"
+#line 1329 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::regexFind, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 3966 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4125 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 303:
-#line 1257 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 323:  // regexFindAll: "object" REGEX_FIND_ALL regexArgs "end of object"
+#line 1335 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::regexFindAll, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 3974 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4133 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 304:
-#line 1263 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 324:  // regexMatch: "object" REGEX_MATCH regexArgs "end of object"
+#line 1341 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::regexMatch, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 3982 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4141 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 305:
-#line 1270 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 325:  // replaceOne: "object" REPLACE_ONE START_ORDERED_OBJECT "find
+                               // argument" expression "input argument" expression "replacement
+                               // argument" expression "end of object" "end of object"
+#line 1348 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::replaceOne,
@@ -4278,11 +4463,13 @@ int PipelineParserGen::parse() {
                                  {KeyFieldname::replacementArg,
                                   YY_MOVE(yystack_[2].value.as<CNode>())}}}}}};
                     }
-#line 3993 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4152 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 306:
-#line 1280 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 326:  // replaceAll: "object" REPLACE_ALL START_ORDERED_OBJECT "find
+                               // argument" expression "input argument" expression "replacement
+                               // argument" expression "end of object" "end of object"
+#line 1358 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::replaceAll,
@@ -4292,51 +4479,54 @@ int PipelineParserGen::parse() {
                                  {KeyFieldname::replacementArg,
                                   YY_MOVE(yystack_[2].value.as<CNode>())}}}}}};
                     }
-#line 4004 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4163 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 307:
-#line 1289 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 327:  // split: "object" SPLIT "array" expression expression "end of array"
+                               // "end of object"
+#line 1367 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::split,
                              CNode{CNode::ArrayChildren{YY_MOVE(yystack_[3].value.as<CNode>()),
                                                         YY_MOVE(yystack_[2].value.as<CNode>())}}}}};
                     }
-#line 4013 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4172 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 308:
-#line 1296 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 328:  // strLenBytes: "object" STR_LEN_BYTES expression "end of object"
+#line 1374 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::strLenBytes, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 4022 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4181 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 309:
-#line 1303 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 329:  // strLenCP: "object" STR_LEN_CP expression "end of object"
+#line 1381 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::strLenCP, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 4031 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4190 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 310:
-#line 1311 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 330:  // strcasecmp: "object" STR_CASE_CMP "array" expression expression
+                               // "end of array" "end of object"
+#line 1389 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::strcasecmp,
                              CNode{CNode::ArrayChildren{YY_MOVE(yystack_[3].value.as<CNode>()),
                                                         YY_MOVE(yystack_[2].value.as<CNode>())}}}}};
                     }
-#line 4040 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4199 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 311:
-#line 1319 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 331:  // substr: "object" SUBSTR "array" expression expression expression
+                               // "end of array" "end of object"
+#line 1397 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::substr,
@@ -4344,11 +4534,12 @@ int PipelineParserGen::parse() {
                                                         YY_MOVE(yystack_[3].value.as<CNode>()),
                                                         YY_MOVE(yystack_[2].value.as<CNode>())}}}}};
                     }
-#line 4049 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4208 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 312:
-#line 1327 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 332:  // substrBytes: "object" SUBSTR_BYTES "array" expression expression
+                               // expression "end of array" "end of object"
+#line 1405 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::substrBytes,
@@ -4356,11 +4547,12 @@ int PipelineParserGen::parse() {
                                                         YY_MOVE(yystack_[3].value.as<CNode>()),
                                                         YY_MOVE(yystack_[2].value.as<CNode>())}}}}};
                     }
-#line 4058 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4217 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 313:
-#line 1335 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 333:  // substrCP: "object" SUBSTR_CP "array" expression expression
+                               // expression "end of array" "end of object"
+#line 1413 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::substrCP,
@@ -4368,440 +4560,579 @@ int PipelineParserGen::parse() {
                                                         YY_MOVE(yystack_[3].value.as<CNode>()),
                                                         YY_MOVE(yystack_[2].value.as<CNode>())}}}}};
                     }
-#line 4067 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4226 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 314:
-#line 1342 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 334:  // toLower: "object" TO_LOWER expression "end of object"
+#line 1420 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::toLower, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 4075 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4234 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 315:
-#line 1348 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 335:  // toUpper: "object" TO_UPPER expression "end of object"
+#line 1426 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::toUpper, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 4083 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4242 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 316:
-#line 1354 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 336:  // metaSortKeyword: "randVal"
+#line 1432 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{KeyValue::randVal};
+                    }
+#line 4250 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 337:  // metaSortKeyword: "textScore"
+#line 1435 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{KeyValue::textScore};
+                    }
+#line 4258 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 338:  // metaSort: "object" META metaSortKeyword "end of object"
+#line 1441 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
+                            {KeyFieldname::meta, YY_MOVE(yystack_[1].value.as<CNode>())}}};
+                    }
+#line 4266 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 339:  // sortSpecs: "object" specList "end of object"
+#line 1447 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = YY_MOVE(yystack_[1].value.as<CNode>());
+                    }
+#line 4274 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 340:  // specList: %empty
+#line 1452 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode::noopLeaf();
+                    }
+#line 4282 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 341:  // specList: specList sortSpec
+#line 1455 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = YY_MOVE(yystack_[1].value.as<CNode>());
+                        yylhs.value.as<CNode>().objectChildren().emplace_back(
+                            YY_MOVE(yystack_[0].value.as<std::pair<CNode::Fieldname, CNode>>()));
+                    }
+#line 4291 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 342:  // oneOrNegOne: "1 (int)"
+#line 1462 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{KeyValue::intOneKey};
+                    }
+#line 4299 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 343:  // oneOrNegOne: "-1 (int)"
+#line 1465 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{KeyValue::intNegOneKey};
+                    }
+#line 4307 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 344:  // oneOrNegOne: "1 (long)"
+#line 1468 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{KeyValue::longOneKey};
+                    }
+#line 4315 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 345:  // oneOrNegOne: "-1 (long)"
+#line 1471 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{KeyValue::longNegOneKey};
+                    }
+#line 4323 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 346:  // oneOrNegOne: "1 (double)"
+#line 1474 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{KeyValue::doubleOneKey};
+                    }
+#line 4331 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 347:  // oneOrNegOne: "-1 (double)"
+#line 1477 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{KeyValue::doubleNegOneKey};
+                    }
+#line 4339 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 348:  // oneOrNegOne: "1 (decimal)"
+#line 1480 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{KeyValue::decimalOneKey};
+                    }
+#line 4347 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 349:  // oneOrNegOne: "-1 (decimal)"
+#line 1483 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<CNode>() = CNode{KeyValue::decimalNegOneKey};
+                    }
+#line 4355 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 350:  // sortSpec: valueFieldname metaSort
+#line 1488 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<std::pair<CNode::Fieldname, CNode>>() = {
+                            YY_MOVE(yystack_[1].value.as<CNode::Fieldname>()),
+                            YY_MOVE(yystack_[0].value.as<CNode>())};
+                    }
+#line 4363 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 351:  // sortSpec: valueFieldname oneOrNegOne
+#line 1490 "pipeline_grammar.yy"
+                    {
+                        yylhs.value.as<std::pair<CNode::Fieldname, CNode>>() = {
+                            YY_MOVE(yystack_[1].value.as<CNode::Fieldname>()),
+                            YY_MOVE(yystack_[0].value.as<CNode>())};
+                    }
+#line 4371 "pipeline_parser_gen.cpp"
+                    break;
+
+                    case 352:  // literalEscapes: const
+#line 1496 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4089 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4377 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 317:
-#line 1354 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 353:  // literalEscapes: literal
+#line 1496 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4095 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4383 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 318:
-#line 1358 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 354:  // const: "object" CONST_EXPR "array" value "end of array" "end of
+                               // object"
+#line 1500 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::constExpr,
                              CNode{CNode::ArrayChildren{YY_MOVE(yystack_[2].value.as<CNode>())}}}}};
                     }
-#line 4104 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4392 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 319:
-#line 1365 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 355:  // literal: "object" LITERAL "array" value "end of array" "end of
+                               // object"
+#line 1507 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::literal,
                              CNode{CNode::ArrayChildren{YY_MOVE(yystack_[2].value.as<CNode>())}}}}};
                     }
-#line 4113 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4401 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 320:
-#line 1372 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 356:  // value: simpleValue
+#line 1514 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4119 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4407 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 321:
-#line 1372 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 357:  // value: compoundValue
+#line 1514 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4125 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4413 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 322:
-#line 1376 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 358:  // compoundValue: valueArray
+#line 1518 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4131 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4419 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 323:
-#line 1376 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 359:  // compoundValue: valueObject
+#line 1518 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4137 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4425 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 324:
-#line 1380 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 360:  // valueArray: "array" values "end of array"
+#line 1522 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() =
                             CNode{YY_MOVE(yystack_[1].value.as<std::vector<CNode>>())};
                     }
-#line 4145 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4433 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 325:
-#line 1386 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 361:  // values: %empty
+#line 1528 "pipeline_grammar.yy"
                     {
                     }
-#line 4151 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4439 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 326:
-#line 1387 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 362:  // values: value values
+#line 1529 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::vector<CNode>>() =
                             YY_MOVE(yystack_[0].value.as<std::vector<CNode>>());
                         yylhs.value.as<std::vector<CNode>>().emplace_back(
                             YY_MOVE(yystack_[1].value.as<CNode>()));
                     }
-#line 4160 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4448 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 327:
-#line 1394 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 363:  // valueObject: "object" valueFields "end of object"
+#line 1536 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[1].value.as<CNode>());
                     }
-#line 4168 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4456 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 328:
-#line 1400 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 364:  // valueFields: %empty
+#line 1542 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode::noopLeaf();
                     }
-#line 4176 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4464 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 329:
-#line 1403 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 365:  // valueFields: valueFields valueField
+#line 1545 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[1].value.as<CNode>());
                         yylhs.value.as<CNode>().objectChildren().emplace_back(
                             YY_MOVE(yystack_[0].value.as<std::pair<CNode::Fieldname, CNode>>()));
                     }
-#line 4185 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4473 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 330:
-#line 1410 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 366:  // valueField: valueFieldname value
+#line 1552 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::pair<CNode::Fieldname, CNode>>() = {
                             YY_MOVE(yystack_[1].value.as<CNode::Fieldname>()),
                             YY_MOVE(yystack_[0].value.as<CNode>())};
                     }
-#line 4193 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4481 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 331:
-#line 1417 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 367:  // valueFieldname: invariableUserFieldname
+#line 1559 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() =
                             YY_MOVE(yystack_[0].value.as<CNode::Fieldname>());
                     }
-#line 4199 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4487 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 332:
-#line 1418 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 368:  // valueFieldname: stageAsUserFieldname
+#line 1560 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() =
                             YY_MOVE(yystack_[0].value.as<CNode::Fieldname>());
                     }
-#line 4205 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4493 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 333:
-#line 1419 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 369:  // valueFieldname: argAsUserFieldname
+#line 1561 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() =
                             YY_MOVE(yystack_[0].value.as<CNode::Fieldname>());
                     }
-#line 4211 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4499 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 334:
-#line 1420 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 370:  // valueFieldname: aggExprAsUserFieldname
+#line 1562 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() =
                             YY_MOVE(yystack_[0].value.as<CNode::Fieldname>());
                     }
-#line 4217 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4505 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 335:
-#line 1421 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 371:  // valueFieldname: idAsUserFieldname
+#line 1563 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode::Fieldname>() =
                             YY_MOVE(yystack_[0].value.as<CNode::Fieldname>());
                     }
-#line 4223 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4511 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 336:
-#line 1424 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 372:  // compExprs: cmp
+#line 1566 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4229 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4517 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 337:
-#line 1424 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 373:  // compExprs: eq
+#line 1566 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4235 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4523 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 338:
-#line 1424 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 374:  // compExprs: gt
+#line 1566 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4241 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4529 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 339:
-#line 1424 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 375:  // compExprs: gte
+#line 1566 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4247 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4535 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 340:
-#line 1424 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 376:  // compExprs: lt
+#line 1566 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4253 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4541 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 341:
-#line 1424 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 377:  // compExprs: lte
+#line 1566 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4259 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4547 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 342:
-#line 1424 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 378:  // compExprs: ne
+#line 1566 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4265 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4553 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 343:
-#line 1426 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 379:  // cmp: "object" CMP exprFixedTwoArg "end of object"
+#line 1568 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::cmp, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 4274 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4562 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 344:
-#line 1431 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 380:  // eq: "object" EQ exprFixedTwoArg "end of object"
+#line 1573 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::eq, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 4283 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4571 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 345:
-#line 1436 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 381:  // gt: "object" GT exprFixedTwoArg "end of object"
+#line 1578 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::gt, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 4292 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4580 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 346:
-#line 1441 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 382:  // gte: "object" GTE exprFixedTwoArg "end of object"
+#line 1583 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::gte, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 4301 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4589 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 347:
-#line 1446 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 383:  // lt: "object" LT exprFixedTwoArg "end of object"
+#line 1588 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::lt, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 4310 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4598 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 348:
-#line 1451 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 384:  // lte: "object" LTE exprFixedTwoArg "end of object"
+#line 1593 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::lte, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 4319 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4607 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 349:
-#line 1456 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 385:  // ne: "object" NE exprFixedTwoArg "end of object"
+#line 1598 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::ne, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 4328 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4616 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 350:
-#line 1462 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 386:  // typeExpression: convert
+#line 1604 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4334 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4622 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 351:
-#line 1463 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 387:  // typeExpression: toBool
+#line 1605 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4340 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4628 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 352:
-#line 1464 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 388:  // typeExpression: toDate
+#line 1606 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4346 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4634 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 353:
-#line 1465 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 389:  // typeExpression: toDecimal
+#line 1607 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4352 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4640 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 354:
-#line 1466 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 390:  // typeExpression: toDouble
+#line 1608 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4358 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4646 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 355:
-#line 1467 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 391:  // typeExpression: toInt
+#line 1609 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4364 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4652 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 356:
-#line 1468 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 392:  // typeExpression: toLong
+#line 1610 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4370 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4658 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 357:
-#line 1469 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 393:  // typeExpression: toObjectId
+#line 1611 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4376 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4664 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 358:
-#line 1470 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 394:  // typeExpression: toString
+#line 1612 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4382 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4670 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 359:
-#line 1471 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 395:  // typeExpression: type
+#line 1613 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = YY_MOVE(yystack_[0].value.as<CNode>());
                     }
-#line 4388 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4676 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 360:
-#line 1476 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 396:  // onErrorArg: %empty
+#line 1618 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::pair<CNode::Fieldname, CNode>>() =
                             std::pair{KeyFieldname::onErrorArg, CNode{KeyValue::absentKey}};
                     }
-#line 4396 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4684 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 361:
-#line 1479 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 397:  // onErrorArg: "onError argument" expression
+#line 1621 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::pair<CNode::Fieldname, CNode>>() = std::pair{
                             KeyFieldname::onErrorArg, YY_MOVE(yystack_[0].value.as<CNode>())};
                     }
-#line 4404 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4692 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 362:
-#line 1486 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 398:  // onNullArg: %empty
+#line 1628 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::pair<CNode::Fieldname, CNode>>() =
                             std::pair{KeyFieldname::onNullArg, CNode{KeyValue::absentKey}};
                     }
-#line 4412 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4700 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 363:
-#line 1489 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 399:  // onNullArg: "onNull argument" expression
+#line 1631 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<std::pair<CNode::Fieldname, CNode>>() = std::pair{
                             KeyFieldname::onNullArg, YY_MOVE(yystack_[0].value.as<CNode>())};
                     }
-#line 4420 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4708 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 364:
-#line 1496 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 400:  // convert: "object" CONVERT START_ORDERED_OBJECT "input argument"
+                               // expression onErrorArg onNullArg "to argument" expression "end of
+                               // object" "end of object"
+#line 1638 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::convert,
@@ -4813,92 +5144,92 @@ int PipelineParserGen::parse() {
                                  YY_MOVE(yystack_[4]
                                              .value.as<std::pair<CNode::Fieldname, CNode>>())}}}}};
                     }
-#line 4431 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4719 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 365:
-#line 1505 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 401:  // toBool: "object" TO_BOOL expression "end of object"
+#line 1647 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::toBool, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 4439 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4727 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 366:
-#line 1510 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 402:  // toDate: "object" TO_DATE expression "end of object"
+#line 1652 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::toDate, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 4447 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4735 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 367:
-#line 1515 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 403:  // toDecimal: "object" TO_DECIMAL expression "end of object"
+#line 1657 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::toDecimal, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 4455 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4743 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 368:
-#line 1520 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 404:  // toDouble: "object" TO_DOUBLE expression "end of object"
+#line 1662 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::toDouble, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 4463 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4751 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 369:
-#line 1525 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 405:  // toInt: "object" TO_INT expression "end of object"
+#line 1667 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::toInt, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 4471 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4759 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 370:
-#line 1530 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 406:  // toLong: "object" TO_LONG expression "end of object"
+#line 1672 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::toLong, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 4479 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4767 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 371:
-#line 1535 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 407:  // toObjectId: "object" TO_OBJECT_ID expression "end of object"
+#line 1677 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::toObjectId, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 4487 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4775 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 372:
-#line 1540 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 408:  // toString: "object" TO_STRING expression "end of object"
+#line 1682 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::toString, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 4495 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4783 "pipeline_parser_gen.cpp"
                     break;
 
-                    case 373:
-#line 1545 "src/mongo/db/cst/pipeline_grammar.yy"
+                    case 409:  // type: "object" TYPE expression "end of object"
+#line 1687 "pipeline_grammar.yy"
                     {
                         yylhs.value.as<CNode>() = CNode{CNode::ObjectChildren{
                             {KeyFieldname::type, YY_MOVE(yystack_[1].value.as<CNode>())}}};
                     }
-#line 4503 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4791 "pipeline_parser_gen.cpp"
                     break;
 
 
-#line 4507 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 4795 "pipeline_parser_gen.cpp"
 
                     default:
                         break;
@@ -4914,7 +5245,6 @@ int PipelineParserGen::parse() {
             YY_SYMBOL_PRINT("-> $$ =", yylhs);
             yypop_(yylen);
             yylen = 0;
-            YY_STACK_PRINT();
 
             // Shift the result of the reduction.
             yypush_(YY_NULLPTR, YY_MOVE(yylhs));
@@ -4929,7 +5259,9 @@ int PipelineParserGen::parse() {
         // If not already recovering from an error, report this error.
         if (!yyerrstatus_) {
             ++yynerrs_;
-            error(yyla.location, yysyntax_error_(yystack_[0].state, yyla));
+            context yyctx(*this, yyla);
+            std::string msg = yysyntax_error_(yyctx);
+            error(yyla.location, YY_MOVE(msg));
         }
 
 
@@ -4939,7 +5271,7 @@ int PipelineParserGen::parse() {
                error, discard it.  */
 
             // Return failure if at end of input.
-            if (yyla.type_get() == yyeof_)
+            if (yyla.kind() == symbol_kind::S_YYEOF)
                 YYABORT;
             else if (!yyla.empty()) {
                 yy_destroy_("Error: discarding", yyla);
@@ -4964,6 +5296,7 @@ int PipelineParserGen::parse() {
            this YYERROR.  */
         yypop_(yylen);
         yylen = 0;
+        YY_STACK_PRINT();
         goto yyerrlab1;
 
 
@@ -4972,28 +5305,29 @@ int PipelineParserGen::parse() {
     `-------------------------------------------------------------*/
     yyerrlab1:
         yyerrstatus_ = 3;  // Each real token shifted decrements this.
-        {
-            stack_symbol_type error_token;
-            for (;;) {
-                yyn = yypact_[+yystack_[0].state];
-                if (!yy_pact_value_is_default_(yyn)) {
-                    yyn += yy_error_token_;
-                    if (0 <= yyn && yyn <= yylast_ && yycheck_[yyn] == yy_error_token_) {
-                        yyn = yytable_[yyn];
-                        if (0 < yyn)
-                            break;
-                    }
+        // Pop stack until we find a state that shifts the error token.
+        for (;;) {
+            yyn = yypact_[+yystack_[0].state];
+            if (!yy_pact_value_is_default_(yyn)) {
+                yyn += symbol_kind::S_YYerror;
+                if (0 <= yyn && yyn <= yylast_ && yycheck_[yyn] == symbol_kind::S_YYerror) {
+                    yyn = yytable_[yyn];
+                    if (0 < yyn)
+                        break;
                 }
+            }
 
-                // Pop the current state because it cannot handle the error token.
-                if (yystack_.size() == 1)
-                    YYABORT;
+            // Pop the current state because it cannot handle the error token.
+            if (yystack_.size() == 1)
+                YYABORT;
 
-                yyerror_range[1].location = yystack_[0].location;
-                yy_destroy_("Error: popping", yystack_[0]);
-                yypop_();
-                YY_STACK_PRINT();
-            }
+            yyerror_range[1].location = yystack_[0].location;
+            yy_destroy_("Error: popping", yystack_[0]);
+            yypop_();
+            YY_STACK_PRINT();
+        }
+        {
+            stack_symbol_type error_token;
 
             yyerror_range[2].location = yyla.location;
             YYLLOC_DEFAULT(error_token.location, yyerror_range, 2);
@@ -5031,6 +5365,7 @@ int PipelineParserGen::parse() {
         /* Do not reclaim the symbols of the rule whose action triggered
            this YYABORT or YYACCEPT.  */
         yypop_(yylen);
+        YY_STACK_PRINT();
         while (1 < yystack_.size()) {
             yy_destroy_("Cleanup: popping", yystack_[0]);
             yypop_();
@@ -5059,16 +5394,85 @@ void PipelineParserGen::error(const syntax_error& yyexc) {
     error(yyexc.location, yyexc.what());
 }
 
-// Generate an error message.
-std::string PipelineParserGen::yysyntax_error_(state_type yystate, const symbol_type& yyla) const {
-    // Number of reported tokens (one for the "unexpected", one per
-    // "expected").
-    std::ptrdiff_t yycount = 0;
-    // Its maximum.
-    enum { YYERROR_VERBOSE_ARGS_MAXIMUM = 5 };
-    // Arguments of yyformat.
-    char const* yyarg[YYERROR_VERBOSE_ARGS_MAXIMUM];
+/* Return YYSTR after stripping away unnecessary quotes and
+   backslashes, so that it's suitable for yyerror.  The heuristic is
+   that double-quoting is unnecessary unless the string contains an
+   apostrophe, a comma, or backslash (other than backslash-backslash).
+   YYSTR is taken from yytname.  */
+std::string PipelineParserGen::yytnamerr_(const char* yystr) {
+    if (*yystr == '"') {
+        std::string yyr;
+        char const* yyp = yystr;
+
+        for (;;)
+            switch (*++yyp) {
+                case '\'':
+                case ',':
+                    goto do_not_strip_quotes;
+
+                case '\\':
+                    if (*++yyp != '\\')
+                        goto do_not_strip_quotes;
+                    else
+                        goto append;
+
+                append:
+                default:
+                    yyr += *yyp;
+                    break;
 
+                case '"':
+                    return yyr;
+            }
+    do_not_strip_quotes:;
+    }
+
+    return yystr;
+}
+
+std::string PipelineParserGen::symbol_name(symbol_kind_type yysymbol) {
+    return yytnamerr_(yytname_[yysymbol]);
+}
+
+
+// PipelineParserGen::context.
+PipelineParserGen::context::context(const PipelineParserGen& yyparser, const symbol_type& yyla)
+    : yyparser_(yyparser), yyla_(yyla) {}
+
+int PipelineParserGen::context::expected_tokens(symbol_kind_type yyarg[], int yyargn) const {
+    // Actual number of expected tokens
+    int yycount = 0;
+
+    int yyn = yypact_[+yyparser_.yystack_[0].state];
+    if (!yy_pact_value_is_default_(yyn)) {
+        /* Start YYX at -YYN if negative to avoid negative indexes in
+           YYCHECK.  In other words, skip the first -YYN actions for
+           this state because they are default actions.  */
+        int yyxbegin = yyn < 0 ? -yyn : 0;
+        // Stay within bounds of both yycheck and yytname.
+        int yychecklim = yylast_ - yyn + 1;
+        int yyxend = yychecklim < YYNTOKENS ? yychecklim : YYNTOKENS;
+        for (int yyx = yyxbegin; yyx < yyxend; ++yyx)
+            if (yycheck_[yyx + yyn] == yyx && yyx != symbol_kind::S_YYerror &&
+                !yy_table_value_is_error_(yytable_[yyx + yyn])) {
+                if (!yyarg)
+                    ++yycount;
+                else if (yycount == yyargn)
+                    return 0;
+                else
+                    yyarg[yycount++] = YY_CAST(symbol_kind_type, yyx);
+            }
+    }
+
+    if (yyarg && yycount == 0 && 0 < yyargn)
+        yyarg[0] = symbol_kind::S_YYEMPTY;
+    return yycount;
+}
+
+
+int PipelineParserGen::yy_syntax_error_arguments_(const context& yyctx,
+                                                  symbol_kind_type yyarg[],
+                                                  int yyargn) const {
     /* There are many possibilities here to consider:
        - If this state is a consistent state with a default action, then
          the only way this function was invoked is if the default action
@@ -5093,30 +5497,23 @@ std::string PipelineParserGen::yysyntax_error_(state_type yystate, const symbol_
          one exception: it will still contain any token that will not be
          accepted due to an error action in a later state.
     */
-    if (!yyla.empty()) {
-        symbol_number_type yytoken = yyla.type_get();
-        yyarg[yycount++] = yytname_[yytoken];
-
-        int yyn = yypact_[+yystate];
-        if (!yy_pact_value_is_default_(yyn)) {
-            /* Start YYX at -YYN if negative to avoid negative indexes in
-               YYCHECK.  In other words, skip the first -YYN actions for
-               this state because they are default actions.  */
-            int yyxbegin = yyn < 0 ? -yyn : 0;
-            // Stay within bounds of both yycheck and yytname.
-            int yychecklim = yylast_ - yyn + 1;
-            int yyxend = yychecklim < yyntokens_ ? yychecklim : yyntokens_;
-            for (int yyx = yyxbegin; yyx < yyxend; ++yyx)
-                if (yycheck_[yyx + yyn] == yyx && yyx != yy_error_token_ &&
-                    !yy_table_value_is_error_(yytable_[yyx + yyn])) {
-                    if (yycount == YYERROR_VERBOSE_ARGS_MAXIMUM) {
-                        yycount = 1;
-                        break;
-                    } else
-                        yyarg[yycount++] = yytname_[yyx];
-                }
-        }
+
+    if (!yyctx.lookahead().empty()) {
+        if (yyarg)
+            yyarg[0] = yyctx.token();
+        int yyn = yyctx.expected_tokens(yyarg ? yyarg + 1 : yyarg, yyargn - 1);
+        return yyn + 1;
     }
+    return 0;
+}
+
+// Generate an error message.
+std::string PipelineParserGen::yysyntax_error_(const context& yyctx) const {
+    // Its maximum.
+    enum { YYARGS_MAX = 5 };
+    // Arguments of yyformat.
+    symbol_kind_type yyarg[YYARGS_MAX];
+    int yycount = yy_syntax_error_arguments_(yyctx, yyarg, YYARGS_MAX);
 
     char const* yyformat = YY_NULLPTR;
     switch (yycount) {
@@ -5139,7 +5536,7 @@ std::string PipelineParserGen::yysyntax_error_(state_type yystate, const symbol_
     std::ptrdiff_t yyi = 0;
     for (char const* yyp = yyformat; *yyp; ++yyp)
         if (yyp[0] == '%' && yyp[1] == 's' && yyi < yycount) {
-            yyres += yytnamerr_(yyarg[yyi++]);
+            yyres += symbol_name(yyarg[yyi++]);
             ++yyp;
         } else
             yyres += *yyp;
@@ -5147,295 +5544,344 @@ std::string PipelineParserGen::yysyntax_error_(state_type yystate, const symbol_
 }
 
 
-const short PipelineParserGen::yypact_ninf_ = -557;
+const short PipelineParserGen::yypact_ninf_ = -550;
 
 const signed char PipelineParserGen::yytable_ninf_ = -1;
 
 const short PipelineParserGen::yypact_[] = {
-    -56,  -40,  -38,  45,   -6,   -557, -557, -557, -557, 119,  37,   854,  -2,   -8,   0,    3,
-    -8,   -557, 47,   -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557,
-    -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, 529,  -557, -557,
-    -557, -557, 51,   -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557,
-    -557, 73,   -557, 88,   24,   -6,   -557, -557, 529,  -557, -557, -557, -557, -557, -557, -557,
-    -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557,
-    -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557,
-    -557, -557, -557, -557, -557, -557, 359,  -8,   8,    -557, -557, 529,  85,   454,  -557, -557,
-    -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557,
-    738,  -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557,
-    -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557,
-    -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557,
-    -557, -557, -557, 738,  -557, -557, -557, -557, -557, 72,   113,  -557, -557, -557, -557, -557,
-    -557, -557, -557, 529,  -557, -557, -557, -557, -557, -557, -557, 549,  664,  -557, -557, -557,
-    -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557,
-    -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557,
-    -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557,
-    -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557,
-    -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557,
-    -557, -557, -557, -557, -557, -557, -557, -557, -22,  -557, -557, 549,  -557, 100,  549,  61,
-    61,   62,   549,  62,   63,   64,   -557, -557, -557, 67,   62,   549,  549,  62,   62,   68,
-    75,   76,   549,  79,   549,  62,   62,   -557, 83,   86,   62,   87,   61,   89,   -557, -557,
-    -557, -557, -557, 92,   -557, 96,   549,  98,   549,  549,  99,   103,  105,  107,  549,  549,
-    549,  549,  549,  549,  549,  549,  549,  549,  -557, 108,  549,  785,  124,  -557, -557, 158,
-    159,  160,  549,  161,  162,  164,  549,  529,  189,  193,  195,  549,  168,  169,  170,  171,
-    172,  549,  549,  529,  175,  549,  176,  177,  179,  210,  549,  549,  181,  549,  182,  549,
-    183,  208,  185,  186,  214,  215,  549,  210,  549,  196,  549,  197,  198,  549,  549,  549,
-    549,  200,  202,  203,  204,  206,  207,  209,  211,  212,  213,  210,  549,  216,  -557, 549,
-    -557, -557, -557, -557, -557, -557, -557, -557, -557, 549,  -557, -557, -557, 220,  221,  549,
-    549,  549,  549,  -557, -557, -557, -557, -557, 549,  549,  222,  -557, 549,  -557, -557, -557,
-    549,  219,  549,  549,  -557, 223,  -557, 549,  -557, 549,  -557, -557, 549,  549,  549,  232,
-    549,  -557, 549,  -557, -557, 549,  549,  549,  549,  -557, -557, -557, -557, -557, -557, -557,
-    -557, -557, -557, 234,  549,  -557, -557, 224,  225,  227,  237,  249,  249,  230,  549,  549,
-    235,  233,  -557, 549,  238,  549,  236,  239,  260,  264,  265,  243,  549,  244,  245,  549,
-    549,  549,  246,  549,  248,  -557, -557, -557, 549,  270,  549,  266,  266,  251,  549,  250,
-    253,  -557, 254,  255,  256,  258,  -557, 259,  549,  272,  549,  549,  261,  262,  263,  268,
-    267,  273,  277,  271,  278,  279,  -557, 549,  280,  -557, 549,  237,  270,  -557, -557, 281,
-    282,  -557, 283,  -557, 284,  -557, -557, 549,  276,  295,  -557, 285,  -557, -557, 286,  287,
-    288,  -557, 289,  -557, -557, 549,  -557, 270,  291,  -557, -557, -557, -557, 292,  549,  549,
-    -557, -557, -557, -557, -557, 293,  294,  296,  -557, 297,  298,  299,  302,  -557, 304,  305,
-    -557, -557, -557, -557};
+    -108, -65,  -69,  -61,  57,   -27,  -550, -550, -550, -550, -550, -550, 56,   53,   135,  23,
+    -24,  136,  81,   85,   136,  -550, 142,  -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, 760,  -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    127,  -550, 169,  -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, -550, -550, -550, -550, -550, -550, -550, -550, 196,  -550, 237,  166,  -27,  -550, -550,
+    -550, 760,  -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, -550, -550, -550, -550, -550, -550, 207,  -550, -550, -550, 220,  136,  -48,  -550, -550,
+    760,  238,  674,  40,   -550, 1077, 1077, -550, -550, -550, -550, -550, 236,  262,  -550, -550,
+    -550, 760,  -550, -550, -550, 249,  -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, -550, -550, -550, 866,  992,  -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, 36,   -550, -550, -550, 866,  -550, 266,  866,  221,  221,  229,  866,  229,  244,  246,
+    -550, -550, -550, 247,  229,  866,  866,  229,  229,  248,  250,  251,  866,  253,  866,  229,
+    229,  -550, 254,  257,  229,  259,  221,  260,  -550, -550, -550, -550, -550, 261,  -550, 269,
+    866,  270,  866,  866,  271,  272,  273,  274,  866,  866,  866,  866,  866,  866,  866,  866,
+    866,  866,  -550, 275,  866,  1198, 294,  -550, -550, 307,  321,  322,  866,  323,  324,  325,
+    866,  760,  354,  359,  361,  866,  330,  332,  333,  334,  336,  866,  866,  760,  339,  866,
+    341,  342,  343,  380,  866,  866,  347,  866,  348,  866,  352,  382,  355,  356,  387,  388,
+    866,  380,  866,  363,  866,  364,  365,  866,  866,  866,  866,  366,  370,  372,  375,  376,
+    377,  378,  389,  390,  392,  380,  866,  393,  -550, 866,  -550, -550, -550, -550, -550, -550,
+    -550, -550, -550, 866,  -550, -550, -550, 360,  395,  866,  866,  866,  866,  -550, -550, -550,
+    -550, -550, 866,  866,  396,  -550, 866,  -550, -550, -550, 866,  424,  866,  866,  -550, 398,
+    -550, 866,  -550, 866,  -550, -550, 866,  866,  866,  426,  866,  -550, 866,  -550, -550, 866,
+    866,  866,  866,  -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, 428,  866,  -550,
+    -550, 402,  403,  404,  429,  434,  434,  407,  866,  866,  409,  408,  -550, 866,  411,  866,
+    412,  414,  436,  444,  445,  420,  866,  421,  422,  866,  866,  866,  423,  866,  430,  -550,
+    -550, -550, 866,  451,  866,  447,  447,  431,  866,  433,  435,  -550, 438,  440,  441,  437,
+    -550, 446,  866,  453,  866,  866,  448,  449,  450,  452,  454,  455,  456,  458,  459,  461,
+    -550, 866,  466,  -550, 866,  429,  451,  -550, -550, 462,  463,  -550, 464,  -550, 465,  -550,
+    -550, 866,  473,  478,  -550, 467,  -550, -550, 468,  469,  471,  -550, 472,  -550, -550, 866,
+    -550, 451,  474,  -550, -550, -550, -550, 475,  866,  866,  -550, -550, -550, -550, -550, 480,
+    481,  482,  -550, 483,  484,  487,  488,  -550, 490,  491,  -550, -550, -550, -550};
 
 const short PipelineParserGen::yydefact_[] = {
-    0,   0,   0,   0,   5,   2,   59,  3,   1,   0,   0,   0,   0,   0,   0,   0,   0,   7,   0,
-    9,   10,  11,  12,  13,  14,  4,   84,  73,  83,  80,  87,  81,  76,  78,  79,  86,  74,  85,
-    88,  75,  82,  77,  58,  219, 66,  0,   65,  64,  63,  60,  0,   173, 171, 167, 169, 166, 168,
-    170, 172, 18,  19,  20,  21,  23,  25,  0,   22,  0,   0,   5,   175, 174, 325, 328, 150, 153,
-    154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 151, 152, 185, 186, 187, 188, 189,
-    194, 190, 191, 192, 195, 196, 62,  176, 177, 179, 180, 181, 193, 182, 183, 184, 320, 321, 322,
-    323, 178, 61,  16,  0,   0,   0,   8,   6,   325, 0,   0,   113, 89,  91,  90,  114, 96,  128,
-    92,  103, 129, 130, 115, 24,  97,  116, 117, 98,  99,  0,   131, 132, 93,  118, 119, 120, 100,
-    101, 133, 121, 122, 102, 95,  94,  123, 134, 135, 136, 138, 137, 124, 139, 140, 125, 67,  70,
-    71,  72,  69,  68,  143, 141, 142, 144, 145, 146, 126, 104, 105, 106, 107, 108, 109, 147, 110,
-    111, 149, 148, 127, 112, 0,   55,  56,  57,  54,  26,  0,   0,   326, 324, 327, 332, 333, 334,
-    331, 335, 0,   329, 49,  48,  47,  45,  41,  43,  197, 212, 40,  42,  44,  46,  36,  37,  38,
-    39,  50,  51,  52,  29,  30,  31,  32,  33,  34,  35,  27,  53,  202, 203, 204, 220, 221, 205,
-    254, 255, 256, 206, 316, 317, 209, 260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271,
-    272, 273, 274, 275, 276, 277, 278, 279, 281, 280, 207, 336, 337, 338, 339, 340, 341, 342, 208,
-    350, 351, 352, 353, 354, 355, 356, 357, 358, 359, 222, 223, 224, 225, 226, 227, 228, 229, 230,
-    231, 232, 233, 234, 235, 236, 28,  15,  0,   330, 199, 197, 200, 0,   0,   0,   0,   0,   0,
-    0,   0,   0,   7,   7,   7,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
-    0,   7,   0,   0,   0,   0,   0,   0,   7,   7,   7,   7,   7,   0,   7,   0,   0,   0,   0,
-    0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   7,   0,   0,   0,
-    0,   198, 210, 0,   0,   0,   0,   0,   0,   0,   197, 0,   0,   0,   0,   0,   0,   0,   0,
-    0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   294, 0,   0,   0,   0,   0,   0,   0,   0,
-    0,   0,   0,   0,   0,   294, 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
-    0,   0,   0,   0,   0,   0,   294, 0,   0,   211, 0,   216, 217, 215, 218, 213, 17,  239, 237,
-    257, 0,   238, 240, 343, 0,   0,   0,   0,   0,   0,   344, 242, 243, 345, 346, 0,   0,   0,
-    244, 0,   246, 347, 348, 0,   0,   0,   0,   349, 0,   258, 0,   302, 0,   303, 304, 0,   0,
-    0,   0,   0,   251, 0,   308, 309, 0,   0,   0,   0,   365, 366, 367, 368, 369, 370, 314, 371,
-    372, 315, 0,   0,   373, 214, 0,   0,   0,   360, 283, 283, 0,   289, 289, 0,   0,   295, 0,
-    0,   197, 0,   0,   299, 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   201, 282,
-    318, 0,   362, 0,   285, 285, 0,   290, 0,   0,   319, 0,   0,   0,   0,   259, 0,   0,   0,
-    0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   361, 0,   0,   284, 0,   360, 362,
-    241, 291, 0,   0,   245, 0,   247, 0,   249, 300, 0,   0,   0,   250, 0,   307, 310, 0,   0,
-    0,   252, 0,   253, 363, 0,   286, 362, 0,   292, 293, 296, 248, 0,   0,   0,   297, 311, 312,
-    313, 298, 0,   0,   0,   301, 0,   0,   0,   0,   288, 0,   0,   364, 287, 306, 305};
+    0,   0,   0,   0,   0,   6,   2,   68,  3,   340, 4,   1,   0,   0,   0,   0,   0,   0,   0,
+    0,   0,   8,   0,   10,  11,  12,  13,  14,  15,  5,   93,  82,  92,  89,  96,  90,  85,  87,
+    88,  95,  83,  94,  97,  84,  91,  86,  67,  239, 75,  0,   74,  73,  72,  69,  122, 98,  100,
+    99,  123, 105, 137, 101, 112, 138, 139, 124, 339, 106, 125, 126, 107, 108, 140, 141, 102, 127,
+    128, 129, 109, 110, 142, 143, 130, 131, 111, 104, 103, 132, 144, 145, 146, 148, 147, 133, 149,
+    150, 134, 76,  79,  80,  81,  78,  77,  153, 151, 152, 154, 155, 156, 135, 113, 114, 115, 116,
+    117, 118, 157, 119, 120, 159, 158, 136, 121, 368, 369, 370, 367, 371, 0,   341, 0,   193, 192,
+    191, 189, 188, 187, 181, 180, 179, 185, 184, 183, 178, 182, 186, 190, 19,  20,  21,  22,  24,
+    26,  0,   23,  0,   0,   6,   195, 194, 161, 361, 364, 162, 160, 165, 166, 167, 168, 169, 170,
+    171, 172, 173, 174, 175, 176, 177, 163, 164, 205, 206, 207, 208, 209, 214, 210, 211, 212, 215,
+    216, 71,  196, 197, 199, 200, 201, 213, 202, 203, 204, 356, 357, 358, 359, 198, 70,  349, 348,
+    347, 346, 343, 342, 345, 344, 0,   350, 351, 17,  0,   0,   0,   9,   7,   361, 0,   0,   0,
+    25,  0,   0,   64,  65,  66,  63,  27,  0,   0,   362, 360, 363, 0,   365, 336, 337, 0,   58,
+    57,  54,  53,  56,  50,  49,  52,  42,  41,  44,  46,  45,  48,  217, 232, 43,  47,  51,  55,
+    37,  38,  39,  40,  59,  60,  61,  30,  31,  32,  33,  34,  35,  36,  28,  62,  222, 223, 224,
+    240, 241, 225, 274, 275, 276, 226, 352, 353, 229, 280, 281, 282, 283, 284, 285, 286, 287, 288,
+    289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299, 301, 300, 227, 372, 373, 374, 375, 376,
+    377, 378, 228, 386, 387, 388, 389, 390, 391, 392, 393, 394, 395, 242, 243, 244, 245, 246, 247,
+    248, 249, 250, 251, 252, 253, 254, 255, 256, 29,  16,  0,   366, 338, 219, 217, 220, 0,   0,
+    0,   0,   0,   0,   0,   0,   0,   8,   8,   8,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+    0,   0,   0,   0,   0,   8,   0,   0,   0,   0,   0,   0,   8,   8,   8,   8,   8,   0,   8,
+    0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+    8,   0,   0,   0,   0,   218, 230, 0,   0,   0,   0,   0,   0,   0,   217, 0,   0,   0,   0,
+    0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   314, 0,   0,   0,   0,
+    0,   0,   0,   0,   0,   0,   0,   0,   0,   314, 0,   0,   0,   0,   0,   0,   0,   0,   0,
+    0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   314, 0,   0,   231, 0,   236, 237, 235, 238,
+    233, 18,  259, 257, 277, 0,   258, 260, 379, 0,   0,   0,   0,   0,   0,   380, 262, 263, 381,
+    382, 0,   0,   0,   264, 0,   266, 383, 384, 0,   0,   0,   0,   385, 0,   278, 0,   322, 0,
+    323, 324, 0,   0,   0,   0,   0,   271, 0,   328, 329, 0,   0,   0,   0,   401, 402, 403, 404,
+    405, 406, 334, 407, 408, 335, 0,   0,   409, 234, 0,   0,   0,   396, 303, 303, 0,   309, 309,
+    0,   0,   315, 0,   0,   217, 0,   0,   319, 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+    0,   0,   221, 302, 354, 0,   398, 0,   305, 305, 0,   310, 0,   0,   355, 0,   0,   0,   0,
+    279, 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   397, 0,   0,
+    304, 0,   396, 398, 261, 311, 0,   0,   265, 0,   267, 0,   269, 320, 0,   0,   0,   270, 0,
+    327, 330, 0,   0,   0,   272, 0,   273, 399, 0,   306, 398, 0,   312, 313, 316, 268, 0,   0,
+    0,   317, 331, 332, 333, 318, 0,   0,   0,   321, 0,   0,   0,   0,   308, 0,   0,   400, 307,
+    326, 325};
 
 const short PipelineParserGen::yypgoto_[] = {
-    -557, -557, -557, -117, -557, -112, 191,  -109, -115, -557, -557, -557, -557, -557, -114, -113,
-    -105, -104, 4,    -98,  6,    -9,   12,   -96,  -79,  -42,  -84,  -557, -78,  -77,  -76,  -557,
-    -73,  -71,  -69,  -43,  -557, -557, -557, -557, -557, -557, 231,  -557, -557, -557, -557, -557,
-    -557, -557, -557, 136,  2,    -317, -67,  -189, -286, -557, -557, -557, -557, -557, -557, -557,
-    -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -219,
-    -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557,
-    -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557,
-    -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -557, -245,
-    -556, -181, -212, -396, -557, -304, 228,  -182, -557, -557, -557, -557, -17,  -557};
+    -550, -550, -550, -204, -550, -14,  287,  -13,  -12,  306,  -550, -550, -550, -550, -174,
+    -97,  -68,  -51,  -9,   -41,  -8,   -10,  -4,   -39,  -34,  -43,  -64,  -550, -30,  -28,
+    -26,  -550, -22,  -11,  24,   -44,  -550, -550, -550, -550, -550, -550, 316,  -550, -550,
+    -550, -550, -550, -550, -550, -550, 283,  -6,   11,   41,   -35,  -343, -550, -550, -550,
+    -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, -550, -550, -550, -173, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -550,
+    -550, -550, -550, -550, -550, -550, -550, -95,  -549, -29,  -60,  -405, -550, -353, 315,
+    -25,  -550, -550, -550, -550, -550, -550, -550, -550, -550, -550, -18,  -550};
 
 const short PipelineParserGen::yydefgoto_[] = {
-    -1,  195, 447, 196, 45,  46,  198, 47,  48,  211, 200, 452, 212, 49,  90,  91,  92,  93,
-    94,  95,  96,  97,  98,  99,  100, 123, 102, 103, 104, 105, 106, 107, 108, 109, 110, 314,
-    112, 113, 114, 125, 115, 5,   10,  18,  19,  20,  21,  22,  23,  24,  118, 239, 63,  315,
-    316, 387, 241, 242, 379, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255,
-    256, 257, 258, 259, 260, 261, 262, 416, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272,
-    273, 274, 275, 276, 277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 288, 289, 290,
-    291, 292, 293, 294, 295, 296, 297, 298, 299, 300, 301, 302, 303, 304, 305, 306, 307, 308,
-    309, 553, 584, 555, 587, 481, 569, 317, 124, 559, 7,   11,  116, 3,   417, 68};
+    -1,  230, 489, 123, 49,  124, 125, 126, 127, 128, 235, 494, 242, 53,  180, 181, 182, 183, 184,
+    185, 186, 187, 188, 189, 190, 224, 192, 193, 194, 195, 196, 197, 198, 199, 200, 356, 202, 203,
+    204, 226, 205, 6,   13,  22,  23,  24,  25,  26,  27,  28,  219, 280, 151, 357, 358, 429, 282,
+    283, 421, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299, 300,
+    301, 302, 303, 458, 304, 305, 306, 307, 308, 309, 310, 311, 312, 313, 314, 315, 316, 317, 318,
+    319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337,
+    338, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349, 350, 595, 626, 597, 629, 523, 611,
+    359, 225, 601, 8,   14,  206, 10,  15,  216, 217, 245, 129, 4,   459, 156};
 
 const short PipelineParserGen::yytable_[] = {
-    67,  383, 111, 101, 61,  388, 197, 61,  206, 199, 210, 381, 52,  207, 397, 398, 209, 59,  66,
-    60,  59,  404, 60,  406, 51,  62,  52,  495, 62,  111, 225, 226, 616, 384, 385, 4,   202, 53,
-    6,   227, 228, 425, 54,  427, 428, 8,   229, 515, 230, 433, 434, 435, 436, 437, 438, 439, 440,
-    441, 442, 630, 232, 445, 414, 1,   2,   231, 233, 234, 235, 457, 9,   236, 25,  237, 50,  238,
-    64,  240, 466, 65,  111, 225, 226, 69,  472, 473, 461, 117, 476, 57,  227, 228, 119, 482, 483,
-    120, 485, 229, 487, 230, 121, 55,  56,  57,  58,  494, 74,  496, 311, 498, 61,  232, 501, 502,
-    503, 504, 231, 233, 234, 235, 204, 201, 236, 59,  237, 60,  238, 516, 240, 312, 518, 62,  418,
-    419, 389, 382, 219, 386, 390, 391, 519, 396, 395, 401, 399, 400, 522, 523, 524, 525, 402, 403,
-    407, 408, 405, 526, 527, 412, 410, 529, 453, 411, 413, 530, 415, 532, 533, 422, 111, 313, 535,
-    424, 536, 426, 429, 537, 538, 539, 430, 541, 431, 542, 432, 444, 543, 544, 545, 546, 12,  13,
-    14,  15,  16,  17,  454, 455, 456, 458, 459, 548, 460, 463, 464, 465, 467, 468, 469, 470, 471,
-    558, 558, 475, 477, 478, 563, 479, 480, 484, 486, 488, 489, 490, 491, 573, 492, 493, 576, 577,
-    578, 565, 580, 531, 497, 499, 500, 582, 505, 585, 506, 507, 508, 590, 509, 510, 540, 511, 547,
-    512, 513, 514, 552, 598, 517, 600, 601, 520, 521, 528, 534, 549, 554, 550, 448, 551, 451, 557,
-    612, 449, 562, 614, 450, 561, 566, 564, 567, 568, 570, 571, 572, 574, 575, 579, 621, 581, 583,
-    591, 586, 589, 592, 599, 593, 594, 595, 596, 622, 597, 629, 602, 603, 604, 122, 613, 606, 380,
-    605, 633, 634, 609, 607, 392, 393, 394, 608, 623, 610, 611, 208, 617, 618, 619, 620, 624, 625,
-    626, 627, 628, 409, 631, 632, 635, 636, 310, 637, 638, 639, 640, 420, 421, 641, 423, 642, 643,
-    615, 556, 588, 560, 0,   0,   111, 462, 0,   203, 0,   0,   0,   0,   0,   0,   0,   443, 111,
-    474, 126, 127, 128, 26,  27,  28,  29,  30,  31,  32,  33,  34,  35,  36,  37,  38,  39,  40,
-    41,  129, 0,   0,   130, 131, 132, 133, 134, 135, 136, 0,   137, 0,   0,   138, 139, 140, 141,
-    142, 143, 144, 145, 146, 0,   147, 148, 149, 150, 0,   151, 152, 153, 154, 155, 156, 157, 158,
-    159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 0,   0,   175,
-    176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194,
-    44,  126, 127, 128, 26,  27,  28,  29,  30,  31,  32,  33,  34,  35,  36,  37,  38,  39,  40,
-    41,  129, 0,   0,   130, 131, 132, 133, 134, 135, 136, 0,   137, 0,   0,   205, 139, 140, 141,
-    142, 143, 43,  145, 146, 0,   147, 148, 149, 150, 0,   151, 152, 153, 154, 155, 156, 157, 158,
-    159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 0,   0,   175,
-    176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194,
-    44,  70,  71,  0,   0,   0,   0,   0,   0,   0,   51,  0,   52,  0,   0,   0,   0,   0,   0,
-    0,   0,   70,  71,  53,  0,   0,   0,   0,   54,  0,   51,  0,   52,  0,   0,   0,   0,   0,
-    0,   0,   0,   0,   0,   53,  0,   0,   0,   0,   54,  0,   0,   0,   0,   72,  73,  0,   0,
-    0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   219, 220, 0,
-    74,  75,  76,  77,  78,  79,  80,  81,  82,  83,  84,  55,  56,  57,  58,  85,  86,  87,  88,
-    89,  74,  75,  76,  77,  78,  79,  80,  81,  82,  83,  84,  55,  56,  57,  58,  85,  86,  87,
-    88,  89,  318, 319, 320, 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
-    0,   0,   321, 0,   0,   322, 323, 324, 325, 326, 327, 328, 0,   329, 0,   0,   0,   330, 331,
-    332, 333, 334, 0,   335, 336, 0,   337, 338, 339, 340, 0,   341, 342, 343, 344, 345, 346, 347,
-    348, 349, 350, 351, 352, 353, 354, 355, 356, 357, 358, 0,   0,   0,   0,   0,   0,   0,   0,
-    359, 360, 361, 362, 363, 364, 365, 366, 367, 368, 369, 370, 371, 372, 373, 374, 375, 376, 377,
-    378, 213, 214, 0,   0,   0,   0,   0,   0,   0,   215, 0,   216, 0,   0,   0,   0,   0,   0,
-    0,   0,   0,   0,   217, 0,   0,   0,   0,   218, 0,   0,   26,  27,  28,  29,  30,  31,  32,
-    33,  34,  35,  36,  37,  38,  39,  40,  41,  0,   0,   0,   0,   0,   0,   219, 220, 0,   0,
-    0,   0,   0,   0,   446, 0,   0,   0,   0,   0,   43,  0,   0,   0,   0,   0,   0,   0,   0,
-    74,  75,  76,  77,  78,  79,  80,  81,  82,  83,  84,  221, 222, 223, 224, 85,  86,  87,  169,
-    170, 171, 172, 173, 174, 26,  27,  28,  29,  30,  31,  32,  33,  34,  35,  36,  37,  38,  39,
-    40,  41,  0,   0,   0,   0,   0,   0,   44,  0,   0,   0,   0,   0,   0,   0,   42,  0,   0,
-    0,   0,   0,   43,  0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+    50,  51,  52,  155, 423, 201, 191, 149, 147, 148, 149, 147, 148, 150, 154, 231, 150, 7,   426,
+    427, 5,   160, 1,   2,   3,   9,   54,  55,  56,  30,  31,  32,  33,  34,  35,  36,  37,  38,
+    39,  40,  41,  42,  43,  44,  45,  57,  163, 456, 58,  59,  60,  61,  62,  63,  64,  266, 266,
+    11,  65,  12,  537, 164, 130, 66,  67,  68,  69,  70,  71,  47,  72,  73,  134, 135, 136, 74,
+    75,  76,  77,  503, 557, 658, 78,  79,  80,  81,  82,  83,  84,  85,  86,  87,  29,  88,  89,
+    90,  91,  92,  93,  94,  95,  96,  97,  98,  99,  100, 101, 102, 672, 243, 103, 104, 105, 106,
+    107, 108, 109, 201, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 48,  267,
+    267, 244, 16,  17,  18,  19,  20,  21,  30,  31,  32,  33,  34,  35,  36,  37,  38,  39,  40,
+    41,  42,  43,  44,  45,  237, 145, 207, 208, 268, 268, 209, 210, 273, 273, 152, 131, 132, 133,
+    153, 134, 135, 136, 46,  211, 212, 269, 269, 201, 47,  157, 213, 214, 137, 138, 139, 270, 270,
+    271, 271, 140, 141, 142, 272, 272, 201, 354, 274, 274, 275, 275, 276, 276, 232, 234, 277, 277,
+    218, 149, 147, 148, 215, 236, 220, 150, 490, 278, 278, 460, 461, 607, 54,  55,  56,  30,  31,
+    32,  33,  34,  35,  36,  37,  38,  39,  40,  41,  42,  43,  44,  45,  57,  48,  221, 58,  59,
+    60,  61,  62,  63,  64,  222, 279, 279, 65,  143, 144, 145, 146, 228, 67,  68,  69,  70,  71,
+    229, 72,  73,  227, 281, 281, 74,  75,  76,  77,  352, 239, 353, 78,  79,  80,  81,  82,  83,
+    84,  85,  86,  87,  355, 88,  89,  90,  91,  92,  93,  94,  95,  96,  97,  98,  99,  100, 101,
+    102, 424, 260, 103, 104, 105, 106, 107, 108, 109, 428, 110, 111, 112, 113, 114, 115, 116, 117,
+    118, 119, 120, 121, 122, 48,  432, 431, 433, 437, 443, 495, 444, 445, 438, 447, 452, 441, 442,
+    453, 422, 455, 457, 464, 496, 449, 450, 434, 435, 436, 454, 466, 468, 471, 472, 473, 474, 486,
+    497, 498, 500, 501, 502, 505, 451, 506, 507, 509, 425, 510, 511, 512, 430, 513, 462, 463, 517,
+    465, 519, 520, 521, 439, 440, 522, 526, 528, 201, 504, 446, 530, 448, 531, 532, 533, 534, 535,
+    562, 485, 201, 516, 539, 541, 542, 547, 491, 492, 493, 548, 467, 549, 469, 470, 550, 551, 552,
+    553, 475, 476, 477, 478, 479, 480, 481, 482, 483, 484, 554, 555, 487, 556, 559, 563, 570, 573,
+    576, 582, 499, 589, 591, 594, 592, 593, 596, 599, 604, 508, 603, 606, 610, 608, 609, 514, 515,
+    612, 613, 518, 614, 616, 617, 621, 524, 525, 625, 527, 628, 529, 623, 641, 631, 633, 223, 634,
+    536, 638, 538, 635, 540, 636, 637, 543, 544, 545, 546, 639, 655, 644, 645, 646, 664, 647, 648,
+    649, 650, 665, 558, 651, 652, 560, 653, 659, 660, 661, 662, 233, 666, 667, 668, 561, 669, 670,
+    351, 673, 674, 564, 565, 566, 567, 677, 678, 679, 680, 681, 568, 569, 682, 683, 571, 684, 685,
+    241, 572, 657, 574, 575, 598, 630, 238, 577, 0,   578, 0,   602, 579, 580, 581, 0,   583, 0,
+    584, 0,   0,   585, 586, 587, 588, 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   590,
+    0,   0,   0,   0,   0,   0,   0,   0,   0,   600, 600, 0,   0,   0,   605, 0,   0,   0,   0,
+    0,   0,   0,   0,   615, 0,   0,   618, 619, 620, 0,   622, 0,   0,   0,   0,   624, 0,   627,
+    0,   0,   0,   632, 0,   0,   0,   0,   0,   0,   0,   0,   0,   640, 0,   642, 643, 0,   0,
+    0,   0,   0,   0,   0,   0,   0,   0,   0,   654, 0,   0,   656, 0,   0,   0,   0,   0,   0,
+    0,   0,   0,   0,   0,   0,   663, 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+    0,   671, 0,   0,   0,   0,   0,   0,   0,   0,   675, 676, 54,  55,  56,  30,  31,  32,  33,
+    34,  35,  36,  37,  38,  39,  40,  41,  42,  43,  44,  45,  57,  0,   0,   58,  59,  60,  61,
+    62,  63,  64,  0,   0,   0,   65,  0,   0,   0,   0,   240, 67,  68,  69,  70,  71,  47,  72,
+    73,  0,   0,   0,   74,  75,  76,  77,  0,   0,   0,   78,  79,  80,  81,  82,  83,  84,  85,
+    86,  87,  0,   88,  89,  90,  91,  92,  93,  94,  95,  96,  97,  98,  99,  100, 101, 102, 0,
+    0,   103, 104, 105, 106, 107, 108, 109, 0,   110, 111, 112, 113, 114, 115, 116, 117, 118, 119,
+    120, 121, 122, 48,  158, 159, 0,   0,   0,   0,   0,   0,   0,   131, 132, 133, 0,   134, 135,
+    136, 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   137, 138, 139, 0,   0,   0,   0,   140,
+    141, 142, 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   160, 0,   0,   0,   0,   0,   0,
+    0,   0,   0,   0,   0,   0,   0,   0,   0,   161, 162, 0,   0,   0,   0,   0,   0,   0,   163,
+    0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   164, 165, 166, 167, 168,
+    169, 170, 171, 172, 173, 174, 143, 144, 145, 146, 175, 176, 177, 178, 179, 158, 159, 0,   0,
+    0,   0,   0,   0,   0,   131, 132, 133, 0,   134, 135, 136, 0,   0,   0,   0,   0,   0,   0,
+    0,   0,   0,   137, 138, 139, 0,   0,   0,   0,   140, 141, 142, 0,   0,   0,   0,   0,   0,
+    0,   0,   0,   0,   160, 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+    0,   260, 261, 0,   0,   0,   0,   0,   0,   0,   163, 0,   0,   0,   0,   0,   0,   0,   0,
+    0,   0,   0,   0,   0,   0,   164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 143, 144,
+    145, 146, 175, 176, 177, 178, 179, 360, 361, 362, 0,   0,   0,   0,   0,   0,   0,   0,   0,
+    0,   0,   0,   0,   0,   0,   0,   363, 0,   0,   364, 365, 366, 367, 368, 369, 370, 0,   0,
+    0,   371, 0,   0,   0,   0,   0,   372, 373, 374, 375, 376, 0,   377, 378, 0,   0,   0,   379,
+    380, 381, 382, 0,   0,   0,   383, 384, 385, 0,   386, 387, 388, 389, 390, 391, 0,   392, 393,
+    394, 395, 396, 397, 398, 399, 400, 0,   0,   0,   0,   0,   0,   0,   0,   401, 402, 403, 404,
+    405, 406, 407, 0,   408, 409, 410, 411, 412, 413, 414, 415, 416, 417, 418, 419, 420, 246, 247,
+    0,   0,   0,   0,   0,   0,   0,   248, 249, 250, 0,   251, 252, 253, 0,   0,   0,   0,   0,
+    0,   0,   0,   0,   0,   254, 255, 256, 0,   0,   0,   0,   257, 258, 259, 0,   0,   0,   0,
+    0,   0,   0,   0,   0,   0,   160, 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+    0,   0,   0,   260, 261, 0,   0,   0,   0,   0,   0,   0,   163, 0,   0,   0,   0,   0,   0,
+    0,   0,   0,   0,   0,   0,   0,   0,   164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174,
+    262, 263, 264, 265, 175, 176, 177, 30,  31,  32,  33,  34,  35,  36,  37,  38,  39,  40,  41,
+    42,  43,  44,  45,  0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+    0,   0,   0,   488, 0,   0,   0,   0,   0,   47,  0,   0,   0,   0,   0,   0,   0,   0,   0,
     0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
-    0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
-    0,   44};
+    0,   0,   0,   0,   97,  98,  99,  100, 101, 102, 0,   0,   0,   0,   0,   0,   0,   0,   0,
+    0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   48};
 
 const short PipelineParserGen::yycheck_[] = {
-    17,  318, 45,  45,  13,  322, 118, 16,  125, 118, 125, 315, 34,  125, 331, 332, 125, 13,  16,
-    13,  16,  338, 16,  340, 32,  13,  34,  423, 16,  72,  144, 144, 588, 319, 320, 75,  120, 45,
-    76,  144, 144, 358, 50,  360, 361, 0,   144, 443, 144, 366, 367, 368, 369, 370, 371, 372, 373,
-    374, 375, 615, 144, 378, 348, 119, 120, 144, 144, 144, 144, 386, 76,  144, 35,  144, 76,  144,
-    76,  144, 395, 76,  123, 195, 195, 36,  401, 402, 390, 36,  405, 111, 195, 195, 19,  410, 411,
-    7,   413, 195, 415, 195, 76,  109, 110, 111, 112, 422, 98,  424, 36,  426, 119, 195, 429, 430,
-    431, 432, 195, 195, 195, 195, 35,  119, 195, 119, 195, 119, 195, 444, 195, 16,  447, 119, 351,
-    352, 323, 35,  75,  75,  75,  75,  457, 330, 75,  75,  333, 334, 463, 464, 465, 466, 75,  75,
-    341, 342, 75,  472, 473, 346, 75,  476, 36,  75,  75,  480, 75,  482, 483, 75,  211, 211, 487,
-    75,  489, 75,  75,  492, 493, 494, 75,  496, 75,  498, 75,  75,  501, 502, 503, 504, 69,  70,
-    71,  72,  73,  74,  36,  36,  36,  36,  36,  516, 36,  12,  9,   8,   36,  36,  36,  36,  36,
-    526, 527, 36,  36,  36,  531, 36,  6,   36,  36,  36,  12,  36,  36,  540, 10,  10,  543, 544,
-    545, 533, 547, 12,  36,  36,  36,  552, 36,  554, 36,  36,  36,  558, 36,  36,  12,  36,  12,
-    36,  36,  36,  13,  568, 36,  570, 571, 35,  35,  35,  35,  35,  11,  36,  379, 36,  379, 35,
-    583, 379, 35,  586, 379, 36,  36,  35,  35,  15,  12,  12,  35,  35,  35,  35,  599, 35,  14,
-    35,  20,  36,  35,  17,  36,  36,  36,  35,  18,  36,  613, 36,  36,  36,  69,  21,  35,  312,
-    36,  622, 623, 36,  35,  326, 327, 328, 35,  18,  36,  36,  125, 36,  36,  36,  36,  36,  36,
-    36,  36,  36,  343, 36,  36,  36,  36,  195, 36,  36,  36,  36,  353, 354, 36,  356, 36,  36,
-    587, 524, 556, 527, -1,  -1,  391, 391, -1,  123, -1,  -1,  -1,  -1,  -1,  -1,  -1,  376, 403,
-    403, 3,   4,   5,   6,   7,   8,   9,   10,  11,  12,  13,  14,  15,  16,  17,  18,  19,  20,
-    21,  22,  -1,  -1,  25,  26,  27,  28,  29,  30,  31,  -1,  33,  -1,  -1,  36,  37,  38,  39,
-    40,  41,  42,  43,  44,  -1,  46,  47,  48,  49,  -1,  51,  52,  53,  54,  55,  56,  57,  58,
-    59,  60,  61,  62,  63,  64,  65,  66,  67,  68,  69,  70,  71,  72,  73,  74,  -1,  -1,  77,
-    78,  79,  80,  81,  82,  83,  84,  85,  86,  87,  88,  89,  90,  91,  92,  93,  94,  95,  96,
-    97,  3,   4,   5,   6,   7,   8,   9,   10,  11,  12,  13,  14,  15,  16,  17,  18,  19,  20,
-    21,  22,  -1,  -1,  25,  26,  27,  28,  29,  30,  31,  -1,  33,  -1,  -1,  36,  37,  38,  39,
-    40,  41,  42,  43,  44,  -1,  46,  47,  48,  49,  -1,  51,  52,  53,  54,  55,  56,  57,  58,
-    59,  60,  61,  62,  63,  64,  65,  66,  67,  68,  69,  70,  71,  72,  73,  74,  -1,  -1,  77,
-    78,  79,  80,  81,  82,  83,  84,  85,  86,  87,  88,  89,  90,  91,  92,  93,  94,  95,  96,
-    97,  23,  24,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  32,  -1,  34,  -1,  -1,  -1,  -1,  -1,  -1,
-    -1,  -1,  23,  24,  45,  -1,  -1,  -1,  -1,  50,  -1,  32,  -1,  34,  -1,  -1,  -1,  -1,  -1,
-    -1,  -1,  -1,  -1,  -1,  45,  -1,  -1,  -1,  -1,  50,  -1,  -1,  -1,  -1,  75,  76,  -1,  -1,
-    -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  75,  76,  -1,
-    98,  99,  100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116,
-    117, 98,  99,  100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115,
-    116, 117, 3,   4,   5,   -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,
-    -1,  -1,  22,  -1,  -1,  25,  26,  27,  28,  29,  30,  31,  -1,  33,  -1,  -1,  -1,  37,  38,
-    39,  40,  41,  -1,  43,  44,  -1,  46,  47,  48,  49,  -1,  51,  52,  53,  54,  55,  56,  57,
-    58,  59,  60,  61,  62,  63,  64,  65,  66,  67,  68,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,
-    77,  78,  79,  80,  81,  82,  83,  84,  85,  86,  87,  88,  89,  90,  91,  92,  93,  94,  95,
-    96,  23,  24,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  32,  -1,  34,  -1,  -1,  -1,  -1,  -1,  -1,
-    -1,  -1,  -1,  -1,  45,  -1,  -1,  -1,  -1,  50,  -1,  -1,  6,   7,   8,   9,   10,  11,  12,
-    13,  14,  15,  16,  17,  18,  19,  20,  21,  -1,  -1,  -1,  -1,  -1,  -1,  75,  76,  -1,  -1,
-    -1,  -1,  -1,  -1,  36,  -1,  -1,  -1,  -1,  -1,  42,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,
-    98,  99,  100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 69,
-    70,  71,  72,  73,  74,  6,   7,   8,   9,   10,  11,  12,  13,  14,  15,  16,  17,  18,  19,
-    20,  21,  -1,  -1,  -1,  -1,  -1,  -1,  97,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  36,  -1,  -1,
-    -1,  -1,  -1,  42,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,
-    -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,
+    14,  14,  14,  21,  357, 49,  49,  17,  17,  17,  20,  20,  20,  17,  20,  219, 20,  86,  361,
+    362, 85,  69,  130, 131, 132, 86,  3,   4,   5,   6,   7,   8,   9,   10,  11,  12,  13,  14,
+    15,  16,  17,  18,  19,  20,  21,  22,  94,  390, 25,  26,  27,  28,  29,  30,  31,  229, 230,
+    0,   35,  86,  465, 109, 86,  40,  41,  42,  43,  44,  45,  46,  47,  48,  36,  37,  38,  52,
+    53,  54,  55,  432, 485, 630, 59,  60,  61,  62,  63,  64,  65,  66,  67,  68,  39,  70,  71,
+    72,  73,  74,  75,  76,  77,  78,  79,  80,  81,  82,  83,  84,  657, 69,  87,  88,  89,  90,
+    91,  92,  93,  161, 95,  96,  97,  98,  99,  100, 101, 102, 103, 104, 105, 106, 107, 108, 229,
+    230, 94,  79,  80,  81,  82,  83,  84,  6,   7,   8,   9,   10,  11,  12,  13,  14,  15,  16,
+    17,  18,  19,  20,  21,  221, 122, 32,  33,  229, 230, 36,  37,  229, 230, 86,  32,  33,  34,
+    86,  36,  37,  38,  40,  49,  50,  229, 230, 224, 46,  40,  56,  57,  49,  50,  51,  229, 230,
+    229, 230, 56,  57,  58,  229, 230, 241, 241, 229, 230, 229, 230, 229, 230, 219, 219, 229, 230,
+    40,  220, 220, 220, 86,  220, 19,  220, 421, 229, 230, 393, 394, 575, 3,   4,   5,   6,   7,
+    8,   9,   10,  11,  12,  13,  14,  15,  16,  17,  18,  19,  20,  21,  22,  108, 7,   25,  26,
+    27,  28,  29,  30,  31,  86,  229, 230, 35,  120, 121, 122, 123, 40,  41,  42,  43,  44,  45,
+    46,  47,  48,  62,  229, 230, 52,  53,  54,  55,  40,  39,  16,  59,  60,  61,  62,  63,  64,
+    65,  66,  67,  68,  40,  70,  71,  72,  73,  74,  75,  76,  77,  78,  79,  80,  81,  82,  83,
+    84,  39,  85,  87,  88,  89,  90,  91,  92,  93,  85,  95,  96,  97,  98,  99,  100, 101, 102,
+    103, 104, 105, 106, 107, 108, 85,  365, 85,  85,  85,  40,  85,  85,  372, 85,  85,  375, 376,
+    85,  353, 85,  85,  85,  40,  383, 384, 368, 369, 370, 388, 85,  85,  85,  85,  85,  85,  85,
+    40,  40,  40,  40,  40,  12,  385, 9,   8,   40,  360, 40,  40,  40,  364, 40,  395, 396, 40,
+    398, 40,  40,  40,  373, 374, 6,   40,  40,  433, 433, 380, 40,  382, 12,  40,  40,  10,  10,
+    39,  418, 445, 445, 40,  40,  40,  40,  421, 421, 421, 40,  400, 40,  402, 403, 40,  40,  40,
+    40,  408, 409, 410, 411, 412, 413, 414, 415, 416, 417, 40,  40,  420, 40,  40,  39,  39,  12,
+    39,  12,  428, 12,  39,  13,  40,  40,  11,  39,  39,  437, 40,  39,  15,  40,  39,  443, 444,
+    12,  12,  447, 39,  39,  39,  39,  452, 453, 14,  455, 20,  457, 39,  17,  40,  39,  157, 39,
+    464, 39,  466, 40,  468, 40,  40,  471, 472, 473, 474, 40,  21,  40,  40,  40,  18,  40,  39,
+    39,  39,  18,  486, 40,  40,  489, 40,  40,  40,  40,  40,  219, 40,  40,  40,  499, 40,  40,
+    230, 40,  40,  505, 506, 507, 508, 40,  40,  40,  40,  40,  514, 515, 40,  40,  518, 40,  40,
+    226, 522, 629, 524, 525, 566, 598, 224, 529, -1,  531, -1,  569, 534, 535, 536, -1,  538, -1,
+    540, -1,  -1,  543, 544, 545, 546, -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  558,
+    -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  568, 569, -1,  -1,  -1,  573, -1,  -1,  -1,  -1,
+    -1,  -1,  -1,  -1,  582, -1,  -1,  585, 586, 587, -1,  589, -1,  -1,  -1,  -1,  594, -1,  596,
+    -1,  -1,  -1,  600, -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  610, -1,  612, 613, -1,  -1,
+    -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  625, -1,  -1,  628, -1,  -1,  -1,  -1,  -1,  -1,
+    -1,  -1,  -1,  -1,  -1,  -1,  641, -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,
+    -1,  655, -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  664, 665, 3,   4,   5,   6,   7,   8,   9,
+    10,  11,  12,  13,  14,  15,  16,  17,  18,  19,  20,  21,  22,  -1,  -1,  25,  26,  27,  28,
+    29,  30,  31,  -1,  -1,  -1,  35,  -1,  -1,  -1,  -1,  40,  41,  42,  43,  44,  45,  46,  47,
+    48,  -1,  -1,  -1,  52,  53,  54,  55,  -1,  -1,  -1,  59,  60,  61,  62,  63,  64,  65,  66,
+    67,  68,  -1,  70,  71,  72,  73,  74,  75,  76,  77,  78,  79,  80,  81,  82,  83,  84,  -1,
+    -1,  87,  88,  89,  90,  91,  92,  93,  -1,  95,  96,  97,  98,  99,  100, 101, 102, 103, 104,
+    105, 106, 107, 108, 23,  24,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  32,  33,  34,  -1,  36,  37,
+    38,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  49,  50,  51,  -1,  -1,  -1,  -1,  56,
+    57,  58,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  69,  -1,  -1,  -1,  -1,  -1,  -1,
+    -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  85,  86,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  94,
+    -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  109, 110, 111, 112, 113,
+    114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 23,  24,  -1,  -1,
+    -1,  -1,  -1,  -1,  -1,  32,  33,  34,  -1,  36,  37,  38,  -1,  -1,  -1,  -1,  -1,  -1,  -1,
+    -1,  -1,  -1,  49,  50,  51,  -1,  -1,  -1,  -1,  56,  57,  58,  -1,  -1,  -1,  -1,  -1,  -1,
+    -1,  -1,  -1,  -1,  69,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,
+    -1,  85,  86,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  94,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,
+    -1,  -1,  -1,  -1,  -1,  -1,  109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121,
+    122, 123, 124, 125, 126, 127, 128, 3,   4,   5,   -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,
+    -1,  -1,  -1,  -1,  -1,  -1,  -1,  22,  -1,  -1,  25,  26,  27,  28,  29,  30,  31,  -1,  -1,
+    -1,  35,  -1,  -1,  -1,  -1,  -1,  41,  42,  43,  44,  45,  -1,  47,  48,  -1,  -1,  -1,  52,
+    53,  54,  55,  -1,  -1,  -1,  59,  60,  61,  -1,  63,  64,  65,  66,  67,  68,  -1,  70,  71,
+    72,  73,  74,  75,  76,  77,  78,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  87,  88,  89,  90,
+    91,  92,  93,  -1,  95,  96,  97,  98,  99,  100, 101, 102, 103, 104, 105, 106, 107, 23,  24,
+    -1,  -1,  -1,  -1,  -1,  -1,  -1,  32,  33,  34,  -1,  36,  37,  38,  -1,  -1,  -1,  -1,  -1,
+    -1,  -1,  -1,  -1,  -1,  49,  50,  51,  -1,  -1,  -1,  -1,  56,  57,  58,  -1,  -1,  -1,  -1,
+    -1,  -1,  -1,  -1,  -1,  -1,  69,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,
+    -1,  -1,  -1,  85,  86,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  94,  -1,  -1,  -1,  -1,  -1,  -1,
+    -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119,
+    120, 121, 122, 123, 124, 125, 126, 6,   7,   8,   9,   10,  11,  12,  13,  14,  15,  16,  17,
+    18,  19,  20,  21,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,
+    -1,  -1,  -1,  40,  -1,  -1,  -1,  -1,  -1,  46,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,
     -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,
-    -1,  97};
+    -1,  -1,  -1,  -1,  79,  80,  81,  82,  83,  84,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,
+    -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  108};
 
 const short PipelineParserGen::yystos_[] = {
-    0,   119, 120, 260, 75,  162, 76,  257, 0,   76,  163, 258, 69,  70,  71,  72,  73,  74,  164,
-    165, 166, 167, 168, 169, 170, 35,  6,   7,   8,   9,   10,  11,  12,  13,  14,  15,  16,  17,
-    18,  19,  20,  21,  36,  42,  97,  125, 126, 128, 129, 134, 76,  32,  34,  45,  50,  109, 110,
-    111, 112, 139, 141, 142, 143, 173, 76,  76,  173, 261, 262, 36,  23,  24,  75,  76,  98,  99,
-    100, 101, 102, 103, 104, 105, 106, 107, 108, 113, 114, 115, 116, 117, 135, 136, 137, 138, 139,
-    140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158,
-    159, 161, 259, 36,  171, 19,  7,   76,  163, 146, 255, 160, 3,   4,   5,   22,  25,  26,  27,
-    28,  29,  30,  31,  33,  36,  37,  38,  39,  40,  41,  42,  43,  44,  46,  47,  48,  49,  51,
-    52,  53,  54,  55,  56,  57,  58,  59,  60,  61,  62,  63,  64,  65,  66,  67,  68,  69,  70,
-    71,  72,  73,  74,  77,  78,  79,  80,  81,  82,  83,  84,  85,  86,  87,  88,  89,  90,  91,
-    92,  93,  94,  95,  96,  122, 124, 126, 127, 128, 131, 173, 147, 255, 35,  36,  124, 126, 127,
-    128, 129, 130, 133, 23,  24,  32,  34,  45,  50,  75,  76,  109, 110, 111, 112, 135, 136, 137,
-    138, 140, 144, 145, 147, 149, 150, 151, 153, 154, 155, 172, 175, 177, 178, 180, 181, 182, 183,
-    184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 201, 202, 203,
-    204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222,
-    223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241,
-    242, 243, 244, 245, 246, 247, 172, 36,  16,  146, 156, 174, 175, 254, 3,   4,   5,   22,  25,
-    26,  27,  28,  29,  30,  31,  33,  37,  38,  39,  40,  41,  43,  44,  46,  47,  48,  49,  51,
-    52,  53,  54,  55,  56,  57,  58,  59,  60,  61,  62,  63,  64,  65,  66,  67,  68,  77,  78,
-    79,  80,  81,  82,  83,  84,  85,  86,  87,  88,  89,  90,  91,  92,  93,  94,  95,  96,  179,
-    142, 254, 35,  174, 177, 177, 75,  176, 174, 176, 75,  75,  261, 261, 261, 75,  176, 174, 174,
-    176, 176, 75,  75,  75,  174, 75,  174, 176, 176, 261, 75,  75,  176, 75,  177, 75,  200, 261,
-    200, 200, 261, 261, 75,  261, 75,  174, 75,  174, 174, 75,  75,  75,  75,  174, 174, 174, 174,
-    174, 174, 174, 174, 174, 174, 261, 75,  174, 36,  123, 124, 126, 128, 129, 132, 36,  36,  36,
-    36,  174, 36,  36,  36,  254, 146, 12,  9,   8,   174, 36,  36,  36,  36,  36,  174, 174, 146,
-    36,  174, 36,  36,  36,  6,   252, 174, 174, 36,  174, 36,  174, 36,  12,  36,  36,  10,  10,
-    174, 252, 174, 36,  174, 36,  36,  174, 174, 174, 174, 36,  36,  36,  36,  36,  36,  36,  36,
-    36,  36,  252, 174, 36,  174, 174, 35,  35,  174, 174, 174, 174, 174, 174, 35,  174, 174, 12,
-    174, 174, 35,  174, 174, 174, 174, 174, 12,  174, 174, 174, 174, 174, 174, 12,  174, 35,  36,
-    36,  13,  248, 11,  250, 250, 35,  174, 256, 256, 36,  35,  174, 35,  254, 36,  35,  15,  253,
-    12,  12,  35,  174, 35,  35,  174, 174, 174, 35,  174, 35,  174, 14,  249, 174, 20,  251, 251,
-    36,  174, 35,  35,  36,  36,  36,  35,  36,  174, 17,  174, 174, 36,  36,  36,  36,  35,  35,
-    35,  36,  36,  36,  174, 21,  174, 248, 249, 36,  36,  36,  36,  174, 18,  18,  36,  36,  36,
-    36,  36,  174, 249, 36,  36,  174, 174, 36,  36,  36,  36,  36,  36,  36,  36,  36};
+    0,   130, 131, 132, 278, 85,  174, 86,  269, 86,  272, 0,   86,  175, 270, 273, 79,  80,  81,
+    82,  83,  84,  176, 177, 178, 179, 180, 181, 182, 39,  6,   7,   8,   9,   10,  11,  12,  13,
+    14,  15,  16,  17,  18,  19,  20,  21,  40,  46,  108, 137, 138, 140, 141, 146, 3,   4,   5,
+    22,  25,  26,  27,  28,  29,  30,  31,  35,  40,  41,  42,  43,  44,  45,  47,  48,  52,  53,
+    54,  55,  59,  60,  61,  62,  63,  64,  65,  66,  67,  68,  70,  71,  72,  73,  74,  75,  76,
+    77,  78,  79,  80,  81,  82,  83,  84,  87,  88,  89,  90,  91,  92,  93,  95,  96,  97,  98,
+    99,  100, 101, 102, 103, 104, 105, 106, 107, 136, 138, 139, 140, 141, 142, 277, 86,  32,  33,
+    34,  36,  37,  38,  49,  50,  51,  56,  57,  58,  120, 121, 122, 123, 151, 153, 154, 155, 185,
+    86,  86,  185, 279, 280, 40,  23,  24,  69,  85,  86,  94,  109, 110, 111, 112, 113, 114, 115,
+    116, 117, 118, 119, 124, 125, 126, 127, 128, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156,
+    157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 173, 271, 32,  33,
+    36,  37,  49,  50,  56,  57,  86,  274, 275, 40,  183, 19,  7,   86,  175, 158, 267, 172, 62,
+    40,  46,  134, 136, 138, 139, 140, 143, 185, 159, 267, 39,  40,  142, 145, 69,  94,  276, 23,
+    24,  32,  33,  34,  36,  37,  38,  49,  50,  51,  56,  57,  58,  85,  86,  120, 121, 122, 123,
+    147, 148, 149, 150, 152, 156, 157, 159, 161, 162, 163, 165, 166, 167, 184, 187, 189, 190, 192,
+    193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211,
+    213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231,
+    232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250,
+    251, 252, 253, 254, 255, 256, 257, 258, 259, 184, 40,  16,  158, 40,  168, 186, 187, 266, 3,
+    4,   5,   22,  25,  26,  27,  28,  29,  30,  31,  35,  41,  42,  43,  44,  45,  47,  48,  52,
+    53,  54,  55,  59,  60,  61,  63,  64,  65,  66,  67,  68,  70,  71,  72,  73,  74,  75,  76,
+    77,  78,  87,  88,  89,  90,  91,  92,  93,  95,  96,  97,  98,  99,  100, 101, 102, 103, 104,
+    105, 106, 107, 191, 154, 266, 39,  186, 189, 189, 85,  188, 186, 188, 85,  85,  279, 279, 279,
+    85,  188, 186, 186, 188, 188, 85,  85,  85,  186, 85,  186, 188, 188, 279, 85,  85,  188, 85,
+    189, 85,  212, 279, 212, 212, 279, 279, 85,  279, 85,  186, 85,  186, 186, 85,  85,  85,  85,
+    186, 186, 186, 186, 186, 186, 186, 186, 186, 186, 279, 85,  186, 40,  135, 136, 138, 140, 141,
+    144, 40,  40,  40,  40,  186, 40,  40,  40,  266, 158, 12,  9,   8,   186, 40,  40,  40,  40,
+    40,  186, 186, 158, 40,  186, 40,  40,  40,  6,   264, 186, 186, 40,  186, 40,  186, 40,  12,
+    40,  40,  10,  10,  186, 264, 186, 40,  186, 40,  40,  186, 186, 186, 186, 40,  40,  40,  40,
+    40,  40,  40,  40,  40,  40,  264, 186, 40,  186, 186, 39,  39,  186, 186, 186, 186, 186, 186,
+    39,  186, 186, 12,  186, 186, 39,  186, 186, 186, 186, 186, 12,  186, 186, 186, 186, 186, 186,
+    12,  186, 39,  40,  40,  13,  260, 11,  262, 262, 39,  186, 268, 268, 40,  39,  186, 39,  266,
+    40,  39,  15,  265, 12,  12,  39,  186, 39,  39,  186, 186, 186, 39,  186, 39,  186, 14,  261,
+    186, 20,  263, 263, 40,  186, 39,  39,  40,  40,  40,  39,  40,  186, 17,  186, 186, 40,  40,
+    40,  40,  39,  39,  39,  40,  40,  40,  186, 21,  186, 260, 261, 40,  40,  40,  40,  186, 18,
+    18,  40,  40,  40,  40,  40,  186, 261, 40,  40,  186, 186, 40,  40,  40,  40,  40,  40,  40,
+    40,  40};
 
 const short PipelineParserGen::yyr1_[] = {
-    0,   121, 260, 260, 162, 163, 163, 262, 261, 164, 164, 164, 164, 164, 164, 170, 165, 166, 173,
-    173, 173, 173, 167, 168, 169, 171, 171, 131, 131, 172, 172, 172, 172, 172, 172, 172, 172, 172,
-    172, 172, 172, 172, 172, 172, 172, 172, 172, 172, 172, 172, 172, 172, 172, 172, 122, 122, 122,
-    122, 257, 258, 258, 134, 259, 125, 125, 125, 128, 124, 124, 124, 124, 124, 124, 126, 126, 126,
-    126, 126, 126, 126, 126, 126, 126, 126, 126, 126, 126, 126, 126, 127, 127, 127, 127, 127, 127,
-    127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
-    127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
-    127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 147, 148,
-    161, 149, 150, 151, 153, 154, 155, 135, 136, 137, 138, 140, 144, 145, 139, 139, 141, 141, 142,
-    142, 143, 143, 152, 152, 156, 156, 156, 156, 156, 156, 156, 156, 156, 156, 156, 156, 156, 156,
-    156, 156, 156, 156, 156, 156, 156, 254, 254, 174, 174, 176, 175, 175, 175, 175, 175, 175, 175,
-    175, 177, 178, 179, 179, 132, 123, 123, 123, 123, 129, 180, 180, 180, 180, 180, 180, 180, 180,
-    180, 180, 180, 180, 180, 180, 180, 180, 180, 181, 182, 233, 234, 235, 236, 237, 238, 239, 240,
-    241, 242, 243, 244, 245, 246, 247, 183, 183, 183, 184, 185, 186, 190, 190, 190, 190, 190, 190,
-    190, 190, 190, 190, 190, 190, 190, 190, 190, 190, 190, 190, 190, 190, 190, 190, 191, 250, 250,
-    251, 251, 192, 193, 256, 256, 256, 194, 195, 252, 252, 196, 203, 213, 253, 253, 200, 197, 198,
-    199, 201, 202, 204, 205, 206, 207, 208, 209, 210, 211, 212, 187, 187, 188, 189, 146, 146, 157,
-    157, 158, 255, 255, 159, 160, 160, 133, 130, 130, 130, 130, 130, 214, 214, 214, 214, 214, 214,
-    214, 215, 216, 217, 218, 219, 220, 221, 222, 222, 222, 222, 222, 222, 222, 222, 222, 222, 248,
-    248, 249, 249, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232};
+    0,   133, 278, 278, 278, 174, 175, 175, 280, 279, 176, 176, 176, 176, 176, 176, 182, 177, 178,
+    185, 185, 185, 185, 179, 180, 181, 183, 183, 143, 143, 184, 184, 184, 184, 184, 184, 184, 184,
+    184, 184, 184, 184, 184, 184, 184, 184, 184, 184, 184, 184, 184, 184, 184, 184, 184, 184, 184,
+    184, 184, 184, 184, 184, 184, 134, 134, 134, 134, 269, 270, 270, 146, 271, 137, 137, 137, 140,
+    136, 136, 136, 136, 136, 136, 138, 138, 138, 138, 138, 138, 138, 138, 138, 138, 138, 138, 138,
+    138, 138, 138, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139,
+    139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139,
+    139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139,
+    139, 139, 139, 139, 139, 139, 139, 139, 159, 159, 159, 160, 173, 161, 162, 163, 165, 166, 167,
+    147, 148, 149, 150, 152, 156, 157, 151, 151, 151, 151, 153, 153, 153, 153, 154, 154, 154, 154,
+    155, 155, 155, 155, 164, 164, 168, 168, 168, 168, 168, 168, 168, 168, 168, 168, 168, 168, 168,
+    168, 168, 168, 168, 168, 168, 168, 168, 266, 266, 186, 186, 188, 187, 187, 187, 187, 187, 187,
+    187, 187, 189, 190, 191, 191, 144, 135, 135, 135, 135, 141, 192, 192, 192, 192, 192, 192, 192,
+    192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 193, 194, 245, 246, 247, 248, 249, 250, 251,
+    252, 253, 254, 255, 256, 257, 258, 259, 195, 195, 195, 196, 197, 198, 202, 202, 202, 202, 202,
+    202, 202, 202, 202, 202, 202, 202, 202, 202, 202, 202, 202, 202, 202, 202, 202, 202, 203, 262,
+    262, 263, 263, 204, 205, 268, 268, 268, 206, 207, 264, 264, 208, 215, 225, 265, 265, 212, 209,
+    210, 211, 213, 214, 216, 217, 218, 219, 220, 221, 222, 223, 224, 276, 276, 274, 272, 273, 273,
+    275, 275, 275, 275, 275, 275, 275, 275, 277, 277, 199, 199, 200, 201, 158, 158, 169, 169, 170,
+    267, 267, 171, 172, 172, 145, 142, 142, 142, 142, 142, 226, 226, 226, 226, 226, 226, 226, 227,
+    228, 229, 230, 231, 232, 233, 234, 234, 234, 234, 234, 234, 234, 234, 234, 234, 260, 260, 261,
+    261, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244};
 
 const signed char PipelineParserGen::yyr2_[] = {
-    0, 2, 2, 2, 3, 0, 4, 0, 2, 1, 1, 1, 1, 1, 1, 5,  3,  7, 1, 1, 1, 1, 2, 2, 4, 0, 2,  2,  2,
-    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1,
-    3, 0, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1,
-    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1,
-    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1,
-    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1,
-    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1, 1, 1, 1, 1, 1, 0, 2, 1, 1,  4,  1,
-    1, 1, 1, 1, 1, 1, 1, 3, 3, 0, 2, 2, 1, 1, 1, 1,  1,  1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1,
-    1, 1, 1, 1, 1, 4, 4, 4, 4, 7, 4, 4, 4, 7, 4, 7,  8,  7, 7, 4, 7, 7, 1, 1, 1, 4, 4,  6,  1,
-    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1, 1, 1, 1, 6, 0, 2, 0, 2, 11, 10, 0,
-    1, 2, 8, 8, 0, 2, 8, 8, 8, 0, 2, 7, 4, 4, 4, 11, 11, 7, 4, 4, 7, 8, 8, 8, 4, 4, 1,  1,  6,
-    6, 1, 1, 1, 1, 3, 0, 2, 3, 0, 2, 2, 1, 1, 1, 1,  1,  1, 1, 1, 1, 1, 1, 1, 4, 4, 4,  4,  4,
-    4, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 2, 0, 2,  11, 4, 4, 4, 4, 4, 4, 4, 4, 4};
-
-
+    0, 2, 2, 2, 2, 3, 0, 4,  0,  2, 1,  1, 1, 1, 1, 1, 5, 3, 7, 1, 1, 1, 1, 2, 2, 4,  0,  2, 2, 2,
+    1, 1, 1, 1, 1, 1, 1, 1,  1,  1, 1,  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1, 1, 1,
+    1, 1, 1, 1, 1, 1, 1, 3,  0,  2, 2,  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1, 1, 1,
+    1, 1, 1, 1, 1, 1, 1, 1,  1,  1, 1,  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1, 1, 1,
+    1, 1, 1, 1, 1, 1, 1, 1,  1,  1, 1,  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1, 1, 1,
+    1, 1, 1, 1, 1, 1, 1, 1,  1,  1, 1,  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1, 1, 1,
+    1, 1, 1, 1, 1, 1, 1, 1,  1,  1, 1,  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1, 1, 1,
+    1, 1, 1, 1, 1, 1, 1, 0,  2,  1, 1,  4, 1, 1, 1, 1, 1, 1, 1, 1, 3, 3, 0, 2, 2, 1,  1,  1, 1, 1,
+    1, 1, 1, 1, 1, 1, 1, 1,  1,  1, 1,  1, 1, 1, 1, 1, 1, 4, 4, 4, 4, 7, 4, 4, 4, 7,  4,  7, 8, 7,
+    7, 4, 7, 7, 1, 1, 1, 4,  4,  6, 1,  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  1,  1, 1, 1,
+    1, 1, 6, 0, 2, 0, 2, 11, 10, 0, 1,  2, 8, 8, 0, 2, 8, 8, 8, 0, 2, 7, 4, 4, 4, 11, 11, 7, 4, 4,
+    7, 8, 8, 8, 4, 4, 1, 1,  4,  3, 0,  2, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 6, 6,  1,  1, 1, 1,
+    3, 0, 2, 3, 0, 2, 2, 1,  1,  1, 1,  1, 1, 1, 1, 1, 1, 1, 1, 4, 4, 4, 4, 4, 4, 4,  1,  1, 1, 1,
+    1, 1, 1, 1, 1, 1, 0, 2,  0,  2, 11, 4, 4, 4, 4, 4, 4, 4, 4, 4};
+
+
+#if YYDEBUG || 1
 // YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
-// First, the terminals, then, starting at \a yyntokens_, nonterminals.
+// First, the terminals, then, starting at \a YYNTOKENS, nonterminals.
 const char* const PipelineParserGen::yytname_[] = {"\"EOF\"",
                                                    "error",
-                                                   "$undefined",
+                                                   "\"invalid token\"",
                                                    "ABS",
                                                    "ADD",
                                                    "AND",
@@ -5465,8 +5911,12 @@ const char* const PipelineParserGen::yytname_[] = {"\"EOF\"",
                                                    "CONVERT",
                                                    "DATE_FROM_STRING",
                                                    "DATE_TO_STRING",
+                                                   "\"-1 (decimal)\"",
+                                                   "\"1 (decimal)\"",
                                                    "\"zero (decimal)\"",
                                                    "DIVIDE",
+                                                   "\"-1 (double)\"",
+                                                   "\"1 (double)\"",
                                                    "\"zero (double)\"",
                                                    "\"end of array\"",
                                                    "\"end of object\"",
@@ -5478,21 +5928,27 @@ const char* const PipelineParserGen::yytname_[] = {"\"EOF\"",
                                                    "ID",
                                                    "INDEX_OF_BYTES",
                                                    "INDEX_OF_CP",
+                                                   "\"-1 (int)\"",
+                                                   "\"1 (int)\"",
                                                    "\"zero (int)\"",
                                                    "LITERAL",
                                                    "LN",
                                                    "LOG",
                                                    "LOGTEN",
+                                                   "\"-1 (long)\"",
+                                                   "\"1 (long)\"",
                                                    "\"zero (long)\"",
                                                    "LT",
                                                    "LTE",
                                                    "LTRIM",
+                                                   "META",
                                                    "MOD",
                                                    "MULTIPLY",
                                                    "NE",
                                                    "NOT",
                                                    "OR",
                                                    "POW",
+                                                   "\"randVal\"",
                                                    "REGEX_FIND",
                                                    "REGEX_FIND_ALL",
                                                    "REGEX_MATCH",
@@ -5517,6 +5973,7 @@ const char* const PipelineParserGen::yytname_[] = {"\"EOF\"",
                                                    "SUBSTR_BYTES",
                                                    "SUBSTR_CP",
                                                    "SUBTRACT",
+                                                   "\"textScore\"",
                                                    "TO_BOOL",
                                                    "TO_DATE",
                                                    "TO_DECIMAL",
@@ -5542,10 +5999,10 @@ const char* const PipelineParserGen::yytname_[] = {"\"EOF\"",
                                                    "\"Code\"",
                                                    "\"Symbol\"",
                                                    "\"CodeWScope\"",
-                                                   "\"non-zero integer\"",
-                                                   "\"non-zero long\"",
-                                                   "\"non-zero double\"",
-                                                   "\"non-zero decimal\"",
+                                                   "\"arbitrary integer\"",
+                                                   "\"arbitrary long\"",
+                                                   "\"arbitrary double\"",
+                                                   "\"arbitrary decimal\"",
                                                    "\"Timestamp\"",
                                                    "\"minKey\"",
                                                    "\"maxKey\"",
@@ -5554,6 +6011,7 @@ const char* const PipelineParserGen::yytname_[] = {"\"EOF\"",
                                                    "\"$-prefixed fieldname\"",
                                                    "START_PIPELINE",
                                                    "START_MATCH",
+                                                   "START_SORT",
                                                    "$accept",
                                                    "projectionFieldname",
                                                    "expressionFieldname",
@@ -5693,48 +6151,56 @@ const char* const PipelineParserGen::yytname_[] = {"\"EOF\"",
                                                    "matchExpression",
                                                    "filterFields",
                                                    "filterVal",
+                                                   "sortSpecs",
+                                                   "specList",
+                                                   "metaSort",
+                                                   "oneOrNegOne",
+                                                   "metaSortKeyword",
+                                                   "sortSpec",
                                                    "start",
                                                    "START_ORDERED_OBJECT",
                                                    "$@1",
                                                    YY_NULLPTR};
+#endif
+
 
 #if YYDEBUG
 const short PipelineParserGen::yyrline_[] = {
-    0,    282,  282,  286,  294,  300,  301,  309,  309,  312,  312,  312,  312,  312,  312,  315,
-    325,  331,  341,  341,  341,  341,  345,  350,  355,  371,  374,  381,  384,  390,  391,  392,
-    393,  394,  395,  396,  397,  398,  399,  400,  401,  404,  407,  410,  413,  416,  419,  422,
-    425,  428,  431,  432,  433,  434,  443,  443,  443,  443,  447,  453,  456,  462,  468,  473,
-    473,  473,  477,  485,  488,  491,  494,  497,  500,  509,  512,  515,  518,  521,  524,  527,
-    530,  533,  536,  539,  542,  545,  548,  551,  554,  562,  565,  568,  571,  574,  577,  580,
-    583,  586,  589,  592,  595,  598,  601,  604,  607,  610,  613,  616,  619,  622,  625,  628,
-    631,  634,  637,  640,  643,  646,  649,  652,  655,  658,  661,  664,  667,  670,  673,  676,
-    679,  682,  685,  688,  691,  694,  697,  700,  703,  706,  709,  712,  715,  718,  721,  724,
-    727,  730,  733,  736,  739,  742,  749,  754,  762,  771,  777,  783,  789,  795,  801,  807,
-    813,  819,  825,  831,  837,  843,  849,  852,  858,  861,  867,  870,  876,  879,  885,  888,
-    894,  895,  896,  897,  898,  899,  900,  901,  902,  903,  904,  905,  906,  907,  908,  909,
-    910,  911,  912,  913,  914,  921,  922,  929,  929,  933,  938,  938,  938,  938,  938,  938,
-    939,  939,  945,  953,  959,  962,  969,  976,  976,  976,  976,  980,  986,  986,  986,  986,
-    986,  986,  986,  986,  986,  986,  986,  986,  986,  987,  987,  987,  987,  991,  998,  1004,
-    1009, 1014, 1020, 1025, 1030, 1035, 1041, 1046, 1052, 1061, 1067, 1073, 1078, 1084, 1090, 1090,
-    1090, 1094, 1101, 1108, 1115, 1115, 1115, 1115, 1115, 1115, 1115, 1116, 1116, 1116, 1116, 1116,
-    1116, 1116, 1116, 1117, 1117, 1117, 1117, 1117, 1117, 1117, 1121, 1131, 1134, 1140, 1143, 1149,
-    1158, 1167, 1170, 1173, 1179, 1190, 1201, 1204, 1210, 1218, 1226, 1234, 1237, 1242, 1251, 1257,
-    1263, 1269, 1279, 1289, 1296, 1303, 1310, 1318, 1326, 1334, 1342, 1348, 1354, 1354, 1358, 1365,
-    1372, 1372, 1376, 1376, 1380, 1386, 1387, 1394, 1400, 1403, 1410, 1417, 1418, 1419, 1420, 1421,
-    1424, 1424, 1424, 1424, 1424, 1424, 1424, 1426, 1431, 1436, 1441, 1446, 1451, 1456, 1462, 1463,
-    1464, 1465, 1466, 1467, 1468, 1469, 1470, 1471, 1476, 1479, 1486, 1489, 1495, 1505, 1510, 1515,
-    1520, 1525, 1530, 1535, 1540, 1545};
-
-// Print the state stack on the debug stream.
-void PipelineParserGen::yystack_print_() {
+    0,    297,  297,  301,  305,  312,  318,  319,  327,  327,  330,  330,  330,  330,  330,  330,
+    333,  343,  349,  359,  359,  359,  359,  363,  368,  373,  389,  392,  399,  402,  408,  409,
+    410,  411,  412,  413,  414,  415,  416,  417,  418,  419,  422,  425,  428,  431,  434,  437,
+    440,  443,  446,  449,  452,  455,  458,  461,  464,  467,  470,  473,  474,  475,  476,  485,
+    485,  485,  485,  489,  495,  498,  504,  510,  515,  515,  515,  519,  527,  530,  533,  536,
+    539,  542,  551,  554,  557,  560,  563,  566,  569,  572,  575,  578,  581,  584,  587,  590,
+    593,  596,  604,  607,  610,  613,  616,  619,  622,  625,  628,  631,  634,  637,  640,  643,
+    646,  649,  652,  655,  658,  661,  664,  667,  670,  673,  676,  679,  682,  685,  688,  691,
+    694,  697,  700,  703,  706,  709,  712,  715,  718,  721,  724,  727,  730,  733,  736,  739,
+    742,  745,  748,  751,  754,  757,  760,  763,  766,  769,  772,  775,  778,  781,  784,  787,
+    794,  799,  802,  808,  816,  825,  831,  837,  843,  849,  855,  861,  867,  873,  879,  885,
+    891,  897,  903,  906,  909,  912,  918,  921,  924,  927,  933,  936,  939,  942,  948,  951,
+    954,  957,  963,  966,  972,  973,  974,  975,  976,  977,  978,  979,  980,  981,  982,  983,
+    984,  985,  986,  987,  988,  989,  990,  991,  992,  999,  1000, 1007, 1007, 1011, 1016, 1016,
+    1016, 1016, 1016, 1016, 1017, 1017, 1023, 1031, 1037, 1040, 1047, 1054, 1054, 1054, 1054, 1058,
+    1064, 1064, 1064, 1064, 1064, 1064, 1064, 1064, 1064, 1064, 1064, 1064, 1064, 1065, 1065, 1065,
+    1065, 1069, 1076, 1082, 1087, 1092, 1098, 1103, 1108, 1113, 1119, 1124, 1130, 1139, 1145, 1151,
+    1156, 1162, 1168, 1168, 1168, 1172, 1179, 1186, 1193, 1193, 1193, 1193, 1193, 1193, 1193, 1194,
+    1194, 1194, 1194, 1194, 1194, 1194, 1194, 1195, 1195, 1195, 1195, 1195, 1195, 1195, 1199, 1209,
+    1212, 1218, 1221, 1227, 1236, 1245, 1248, 1251, 1257, 1268, 1279, 1282, 1288, 1296, 1304, 1312,
+    1315, 1320, 1329, 1335, 1341, 1347, 1357, 1367, 1374, 1381, 1388, 1396, 1404, 1412, 1420, 1426,
+    1432, 1435, 1441, 1447, 1452, 1455, 1462, 1465, 1468, 1471, 1474, 1477, 1480, 1483, 1488, 1490,
+    1496, 1496, 1500, 1507, 1514, 1514, 1518, 1518, 1522, 1528, 1529, 1536, 1542, 1545, 1552, 1559,
+    1560, 1561, 1562, 1563, 1566, 1566, 1566, 1566, 1566, 1566, 1566, 1568, 1573, 1578, 1583, 1588,
+    1593, 1598, 1604, 1605, 1606, 1607, 1608, 1609, 1610, 1611, 1612, 1613, 1618, 1621, 1628, 1631,
+    1637, 1647, 1652, 1657, 1662, 1667, 1672, 1677, 1682, 1687};
+
+void PipelineParserGen::yy_stack_print_() const {
     *yycdebug_ << "Stack now";
     for (stack_type::const_iterator i = yystack_.begin(), i_end = yystack_.end(); i != i_end; ++i)
         *yycdebug_ << ' ' << int(i->state);
     *yycdebug_ << '\n';
 }
 
-// Report on the debug stream that the rule \a yyrule is going to be reduced.
-void PipelineParserGen::yy_reduce_print_(int yyrule) {
+void PipelineParserGen::yy_reduce_print_(int yyrule) const {
     int yylno = yyrline_[yyrule];
     int yynrhs = yyr2_[yyrule];
     // Print the symbols being reduced, and their result.
@@ -5746,8 +6212,8 @@ void PipelineParserGen::yy_reduce_print_(int yyrule) {
 #endif  // YYDEBUG
 
 
-#line 58 "src/mongo/db/cst/pipeline_grammar.yy"
+#line 58 "pipeline_grammar.yy"
 }  // namespace mongo
-#line 5457 "src/mongo/db/cst/pipeline_parser_gen.cpp"
+#line 5920 "pipeline_parser_gen.cpp"
 
-#line 1549 "src/mongo/db/cst/pipeline_grammar.yy"
+#line 1691 "pipeline_grammar.yy"
diff --git a/src/mongo/db/cst/pipeline_parser_gen.hpp b/src/mongo/db/cst/pipeline_parser_gen.hpp
index 3e9f17bb5c0..9c9296172ee 100644
--- a/src/mongo/db/cst/pipeline_parser_gen.hpp
+++ b/src/mongo/db/cst/pipeline_parser_gen.hpp
@@ -1,4 +1,4 @@
-// A Bison parser, made by GNU Bison 3.5.4.
+// A Bison parser, made by GNU Bison 3.7.
 
 // Skeleton interface for Bison LALR(1) parsers in C++
 
@@ -32,19 +32,20 @@
 
 
 /**
- ** \file src/mongo/db/cst/pipeline_parser_gen.hpp
+ ** \file pipeline_parser_gen.hpp
  ** Define the mongo::parser class.
  */
 
 // C++ LALR(1) parser skeleton written by Akim Demaille.
 
-// Undocumented macros, especially those whose name start with YY_,
-// are private implementation details.  Do not rely on them.
+// DO NOT RELY ON FEATURES THAT ARE NOT DOCUMENTED in the manual,
+// especially those whose name start with YY_ or yy_.  They are
+// private implementation details that can be changed or removed.
 
-#ifndef YY_YY_SRC_MONGO_DB_CST_PIPELINE_PARSER_GEN_HPP_INCLUDED
-#define YY_YY_SRC_MONGO_DB_CST_PIPELINE_PARSER_GEN_HPP_INCLUDED
+#ifndef YY_YY_PIPELINE_PARSER_GEN_HPP_INCLUDED
+#define YY_YY_PIPELINE_PARSER_GEN_HPP_INCLUDED
 // "%code requires" blocks.
-#line 67 "src/mongo/db/cst/pipeline_grammar.yy"
+#line 67 "pipeline_grammar.yy"
 
 #include "mongo/db/cst/bson_location.h"
 #include "mongo/db/cst/c_node.h"
@@ -59,7 +60,7 @@ class BSONLexer;
 #pragma warning(disable : 4065)
 #endif
 
-#line 63 "src/mongo/db/cst/pipeline_parser_gen.hpp"
+#line 64 "pipeline_parser_gen.hpp"
 
 #include <cassert>
 #include <cstdlib>  // std::abort
@@ -188,9 +189,9 @@ class BSONLexer;
 #define YYDEBUG 0
 #endif
 
-#line 58 "src/mongo/db/cst/pipeline_grammar.yy"
+#line 58 "pipeline_grammar.yy"
 namespace mongo {
-#line 198 "src/mongo/db/cst/pipeline_parser_gen.hpp"
+#line 199 "pipeline_parser_gen.hpp"
 
 
 /// A Bison parser.
@@ -217,6 +218,13 @@ public:
             new (yyas_<T>()) T(YY_MOVE(t));
         }
 
+#if 201103L <= YY_CPLUSPLUS
+        /// Non copyable.
+        semantic_type(const self_type&) = delete;
+        /// Non copyable.
+        self_type& operator=(const self_type&) = delete;
+#endif
+
         /// Destruction, allowed only if empty.
         ~semantic_type() YY_NOEXCEPT {
             YY_ASSERT(!yytypeid_);
@@ -335,9 +343,12 @@ public:
         }
 
     private:
-        /// Prohibit blind copies.
-        self_type& operator=(const self_type&);
+#if YY_CPLUSPLUS < 201103L
+        /// Non copyable.
         semantic_type(const self_type&);
+        /// Non copyable.
+        self_type& operator=(const self_type&);
+#endif
 
         /// Accessor to raw memory as \a T.
         template <typename T>
@@ -489,6 +500,11 @@ public:
             // matchExpression
             // filterFields
             // filterVal
+            // sortSpecs
+            // specList
+            // metaSort
+            // oneOrNegOne
+            // metaSortKeyword
             char dummy7[sizeof(CNode)];
 
             // projectionFieldname
@@ -505,7 +521,7 @@ public:
             // "Date"
             char dummy9[sizeof(Date_t)];
 
-            // "non-zero decimal"
+            // "arbitrary decimal"
             char dummy10[sizeof(Decimal128)];
 
             // "ObjectID"
@@ -526,13 +542,13 @@ public:
             // "undefined"
             char dummy16[sizeof(UserUndefined)];
 
-            // "non-zero double"
+            // "arbitrary double"
             char dummy17[sizeof(double)];
 
-            // "non-zero integer"
+            // "arbitrary integer"
             char dummy18[sizeof(int)];
 
-            // "non-zero long"
+            // "arbitrary long"
             char dummy19[sizeof(long long)];
 
             // projectField
@@ -545,6 +561,7 @@ public:
             // timezoneArg
             // charsArg
             // optionsArg
+            // sortSpec
             char dummy20[sizeof(std::pair<CNode::Fieldname, CNode>)];
 
             // "fieldname"
@@ -593,147 +610,453 @@ public:
         location_type location;
     };
 
-    /// Tokens.
+    /// Token kinds.
     struct token {
-        enum yytokentype {
-            END_OF_FILE = 0,
-            ABS = 3,
-            ADD = 4,
-            AND = 5,
-            ARG_CHARS = 6,
-            ARG_COLL = 7,
-            ARG_DATE = 8,
-            ARG_DATE_STRING = 9,
-            ARG_FIND = 10,
-            ARG_FORMAT = 11,
-            ARG_INPUT = 12,
-            ARG_ON_ERROR = 13,
-            ARG_ON_NULL = 14,
-            ARG_OPTIONS = 15,
-            ARG_PIPELINE = 16,
-            ARG_REGEX = 17,
-            ARG_REPLACEMENT = 18,
-            ARG_SIZE = 19,
-            ARG_TIMEZONE = 20,
-            ARG_TO = 21,
-            ATAN2 = 22,
-            BOOL_FALSE = 23,
-            BOOL_TRUE = 24,
-            CEIL = 25,
-            CMP = 26,
-            CONCAT = 27,
-            CONST_EXPR = 28,
-            CONVERT = 29,
-            DATE_FROM_STRING = 30,
-            DATE_TO_STRING = 31,
-            DECIMAL_ZERO = 32,
-            DIVIDE = 33,
-            DOUBLE_ZERO = 34,
-            END_ARRAY = 35,
-            END_OBJECT = 36,
-            EQ = 37,
-            EXPONENT = 38,
-            FLOOR = 39,
-            GT = 40,
-            GTE = 41,
-            ID = 42,
-            INDEX_OF_BYTES = 43,
-            INDEX_OF_CP = 44,
-            INT_ZERO = 45,
-            LITERAL = 46,
-            LN = 47,
-            LOG = 48,
-            LOGTEN = 49,
-            LONG_ZERO = 50,
-            LT = 51,
-            LTE = 52,
-            LTRIM = 53,
-            MOD = 54,
-            MULTIPLY = 55,
-            NE = 56,
-            NOT = 57,
-            OR = 58,
-            POW = 59,
-            REGEX_FIND = 60,
-            REGEX_FIND_ALL = 61,
-            REGEX_MATCH = 62,
-            REPLACE_ALL = 63,
-            REPLACE_ONE = 64,
-            ROUND = 65,
-            RTRIM = 66,
-            SPLIT = 67,
-            SQRT = 68,
-            STAGE_INHIBIT_OPTIMIZATION = 69,
-            STAGE_LIMIT = 70,
-            STAGE_PROJECT = 71,
-            STAGE_SAMPLE = 72,
-            STAGE_SKIP = 73,
-            STAGE_UNION_WITH = 74,
-            START_ARRAY = 75,
-            START_OBJECT = 76,
-            STR_CASE_CMP = 77,
-            STR_LEN_BYTES = 78,
-            STR_LEN_CP = 79,
-            SUBSTR = 80,
-            SUBSTR_BYTES = 81,
-            SUBSTR_CP = 82,
-            SUBTRACT = 83,
-            TO_BOOL = 84,
-            TO_DATE = 85,
-            TO_DECIMAL = 86,
-            TO_DOUBLE = 87,
-            TO_INT = 88,
-            TO_LONG = 89,
-            TO_LOWER = 90,
-            TO_OBJECT_ID = 91,
-            TO_STRING = 92,
-            TO_UPPER = 93,
-            TRIM = 94,
-            TRUNC = 95,
-            TYPE = 96,
-            FIELDNAME = 97,
-            STRING = 98,
-            BINARY = 99,
-            UNDEFINED = 100,
-            OBJECT_ID = 101,
-            DATE_LITERAL = 102,
-            JSNULL = 103,
-            REGEX = 104,
-            DB_POINTER = 105,
-            JAVASCRIPT = 106,
-            SYMBOL = 107,
-            JAVASCRIPT_W_SCOPE = 108,
-            INT_NON_ZERO = 109,
-            LONG_NON_ZERO = 110,
-            DOUBLE_NON_ZERO = 111,
-            DECIMAL_NON_ZERO = 112,
-            TIMESTAMP = 113,
-            MIN_KEY = 114,
-            MAX_KEY = 115,
-            DOLLAR_STRING = 116,
-            DOLLAR_DOLLAR_STRING = 117,
-            DOLLAR_PREF_FIELDNAME = 118,
-            START_PIPELINE = 119,
-            START_MATCH = 120
+        enum token_kind_type {
+            YYEMPTY = -2,
+            END_OF_FILE = 0,                  // "EOF"
+            YYerror = 1,                      // error
+            YYUNDEF = 2,                      // "invalid token"
+            ABS = 3,                          // ABS
+            ADD = 4,                          // ADD
+            AND = 5,                          // AND
+            ARG_CHARS = 6,                    // "chars argument"
+            ARG_COLL = 7,                     // "coll argument"
+            ARG_DATE = 8,                     // "date argument"
+            ARG_DATE_STRING = 9,              // "dateString argument"
+            ARG_FIND = 10,                    // "find argument"
+            ARG_FORMAT = 11,                  // "format argument"
+            ARG_INPUT = 12,                   // "input argument"
+            ARG_ON_ERROR = 13,                // "onError argument"
+            ARG_ON_NULL = 14,                 // "onNull argument"
+            ARG_OPTIONS = 15,                 // "options argument"
+            ARG_PIPELINE = 16,                // "pipeline argument"
+            ARG_REGEX = 17,                   // "regex argument"
+            ARG_REPLACEMENT = 18,             // "replacement argument"
+            ARG_SIZE = 19,                    // "size argument"
+            ARG_TIMEZONE = 20,                // "timezone argument"
+            ARG_TO = 21,                      // "to argument"
+            ATAN2 = 22,                       // ATAN2
+            BOOL_FALSE = 23,                  // "false"
+            BOOL_TRUE = 24,                   // "true"
+            CEIL = 25,                        // CEIL
+            CMP = 26,                         // CMP
+            CONCAT = 27,                      // CONCAT
+            CONST_EXPR = 28,                  // CONST_EXPR
+            CONVERT = 29,                     // CONVERT
+            DATE_FROM_STRING = 30,            // DATE_FROM_STRING
+            DATE_TO_STRING = 31,              // DATE_TO_STRING
+            DECIMAL_NEGATIVE_ONE = 32,        // "-1 (decimal)"
+            DECIMAL_ONE = 33,                 // "1 (decimal)"
+            DECIMAL_ZERO = 34,                // "zero (decimal)"
+            DIVIDE = 35,                      // DIVIDE
+            DOUBLE_NEGATIVE_ONE = 36,         // "-1 (double)"
+            DOUBLE_ONE = 37,                  // "1 (double)"
+            DOUBLE_ZERO = 38,                 // "zero (double)"
+            END_ARRAY = 39,                   // "end of array"
+            END_OBJECT = 40,                  // "end of object"
+            EQ = 41,                          // EQ
+            EXPONENT = 42,                    // EXPONENT
+            FLOOR = 43,                       // FLOOR
+            GT = 44,                          // GT
+            GTE = 45,                         // GTE
+            ID = 46,                          // ID
+            INDEX_OF_BYTES = 47,              // INDEX_OF_BYTES
+            INDEX_OF_CP = 48,                 // INDEX_OF_CP
+            INT_NEGATIVE_ONE = 49,            // "-1 (int)"
+            INT_ONE = 50,                     // "1 (int)"
+            INT_ZERO = 51,                    // "zero (int)"
+            LITERAL = 52,                     // LITERAL
+            LN = 53,                          // LN
+            LOG = 54,                         // LOG
+            LOGTEN = 55,                      // LOGTEN
+            LONG_NEGATIVE_ONE = 56,           // "-1 (long)"
+            LONG_ONE = 57,                    // "1 (long)"
+            LONG_ZERO = 58,                   // "zero (long)"
+            LT = 59,                          // LT
+            LTE = 60,                         // LTE
+            LTRIM = 61,                       // LTRIM
+            META = 62,                        // META
+            MOD = 63,                         // MOD
+            MULTIPLY = 64,                    // MULTIPLY
+            NE = 65,                          // NE
+            NOT = 66,                         // NOT
+            OR = 67,                          // OR
+            POW = 68,                         // POW
+            RAND_VAL = 69,                    // "randVal"
+            REGEX_FIND = 70,                  // REGEX_FIND
+            REGEX_FIND_ALL = 71,              // REGEX_FIND_ALL
+            REGEX_MATCH = 72,                 // REGEX_MATCH
+            REPLACE_ALL = 73,                 // REPLACE_ALL
+            REPLACE_ONE = 74,                 // REPLACE_ONE
+            ROUND = 75,                       // ROUND
+            RTRIM = 76,                       // RTRIM
+            SPLIT = 77,                       // SPLIT
+            SQRT = 78,                        // SQRT
+            STAGE_INHIBIT_OPTIMIZATION = 79,  // STAGE_INHIBIT_OPTIMIZATION
+            STAGE_LIMIT = 80,                 // STAGE_LIMIT
+            STAGE_PROJECT = 81,               // STAGE_PROJECT
+            STAGE_SAMPLE = 82,                // STAGE_SAMPLE
+            STAGE_SKIP = 83,                  // STAGE_SKIP
+            STAGE_UNION_WITH = 84,            // STAGE_UNION_WITH
+            START_ARRAY = 85,                 // "array"
+            START_OBJECT = 86,                // "object"
+            STR_CASE_CMP = 87,                // STR_CASE_CMP
+            STR_LEN_BYTES = 88,               // STR_LEN_BYTES
+            STR_LEN_CP = 89,                  // STR_LEN_CP
+            SUBSTR = 90,                      // SUBSTR
+            SUBSTR_BYTES = 91,                // SUBSTR_BYTES
+            SUBSTR_CP = 92,                   // SUBSTR_CP
+            SUBTRACT = 93,                    // SUBTRACT
+            TEXT_SCORE = 94,                  // "textScore"
+            TO_BOOL = 95,                     // TO_BOOL
+            TO_DATE = 96,                     // TO_DATE
+            TO_DECIMAL = 97,                  // TO_DECIMAL
+            TO_DOUBLE = 98,                   // TO_DOUBLE
+            TO_INT = 99,                      // TO_INT
+            TO_LONG = 100,                    // TO_LONG
+            TO_LOWER = 101,                   // TO_LOWER
+            TO_OBJECT_ID = 102,               // TO_OBJECT_ID
+            TO_STRING = 103,                  // TO_STRING
+            TO_UPPER = 104,                   // TO_UPPER
+            TRIM = 105,                       // TRIM
+            TRUNC = 106,                      // TRUNC
+            TYPE = 107,                       // TYPE
+            FIELDNAME = 108,                  // "fieldname"
+            STRING = 109,                     // "string"
+            BINARY = 110,                     // "BinData"
+            UNDEFINED = 111,                  // "undefined"
+            OBJECT_ID = 112,                  // "ObjectID"
+            DATE_LITERAL = 113,               // "Date"
+            JSNULL = 114,                     // "null"
+            REGEX = 115,                      // "regex"
+            DB_POINTER = 116,                 // "dbPointer"
+            JAVASCRIPT = 117,                 // "Code"
+            SYMBOL = 118,                     // "Symbol"
+            JAVASCRIPT_W_SCOPE = 119,         // "CodeWScope"
+            INT_OTHER = 120,                  // "arbitrary integer"
+            LONG_OTHER = 121,                 // "arbitrary long"
+            DOUBLE_OTHER = 122,               // "arbitrary double"
+            DECIMAL_OTHER = 123,              // "arbitrary decimal"
+            TIMESTAMP = 124,                  // "Timestamp"
+            MIN_KEY = 125,                    // "minKey"
+            MAX_KEY = 126,                    // "maxKey"
+            DOLLAR_STRING = 127,              // "$-prefixed string"
+            DOLLAR_DOLLAR_STRING = 128,       // "$$-prefixed string"
+            DOLLAR_PREF_FIELDNAME = 129,      // "$-prefixed fieldname"
+            START_PIPELINE = 130,             // START_PIPELINE
+            START_MATCH = 131,                // START_MATCH
+            START_SORT = 132                  // START_SORT
         };
+        /// Backward compatibility alias (Bison 3.6).
+        typedef token_kind_type yytokentype;
     };
 
-    /// (External) token type, as returned by yylex.
-    typedef token::yytokentype token_type;
-
-    /// Symbol type: an internal symbol number.
-    typedef int symbol_number_type;
+    /// Token kind, as returned by yylex.
+    typedef token::yytokentype token_kind_type;
+
+    /// Backward compatibility alias (Bison 3.6).
+    typedef token_kind_type token_type;
+
+    /// Symbol kinds.
+    struct symbol_kind {
+        enum symbol_kind_type {
+            YYNTOKENS = 133,  ///< Number of tokens.
+            S_YYEMPTY = -2,
+            S_YYEOF = 0,                        // "EOF"
+            S_YYerror = 1,                      // error
+            S_YYUNDEF = 2,                      // "invalid token"
+            S_ABS = 3,                          // ABS
+            S_ADD = 4,                          // ADD
+            S_AND = 5,                          // AND
+            S_ARG_CHARS = 6,                    // "chars argument"
+            S_ARG_COLL = 7,                     // "coll argument"
+            S_ARG_DATE = 8,                     // "date argument"
+            S_ARG_DATE_STRING = 9,              // "dateString argument"
+            S_ARG_FIND = 10,                    // "find argument"
+            S_ARG_FORMAT = 11,                  // "format argument"
+            S_ARG_INPUT = 12,                   // "input argument"
+            S_ARG_ON_ERROR = 13,                // "onError argument"
+            S_ARG_ON_NULL = 14,                 // "onNull argument"
+            S_ARG_OPTIONS = 15,                 // "options argument"
+            S_ARG_PIPELINE = 16,                // "pipeline argument"
+            S_ARG_REGEX = 17,                   // "regex argument"
+            S_ARG_REPLACEMENT = 18,             // "replacement argument"
+            S_ARG_SIZE = 19,                    // "size argument"
+            S_ARG_TIMEZONE = 20,                // "timezone argument"
+            S_ARG_TO = 21,                      // "to argument"
+            S_ATAN2 = 22,                       // ATAN2
+            S_BOOL_FALSE = 23,                  // "false"
+            S_BOOL_TRUE = 24,                   // "true"
+            S_CEIL = 25,                        // CEIL
+            S_CMP = 26,                         // CMP
+            S_CONCAT = 27,                      // CONCAT
+            S_CONST_EXPR = 28,                  // CONST_EXPR
+            S_CONVERT = 29,                     // CONVERT
+            S_DATE_FROM_STRING = 30,            // DATE_FROM_STRING
+            S_DATE_TO_STRING = 31,              // DATE_TO_STRING
+            S_DECIMAL_NEGATIVE_ONE = 32,        // "-1 (decimal)"
+            S_DECIMAL_ONE = 33,                 // "1 (decimal)"
+            S_DECIMAL_ZERO = 34,                // "zero (decimal)"
+            S_DIVIDE = 35,                      // DIVIDE
+            S_DOUBLE_NEGATIVE_ONE = 36,         // "-1 (double)"
+            S_DOUBLE_ONE = 37,                  // "1 (double)"
+            S_DOUBLE_ZERO = 38,                 // "zero (double)"
+            S_END_ARRAY = 39,                   // "end of array"
+            S_END_OBJECT = 40,                  // "end of object"
+            S_EQ = 41,                          // EQ
+            S_EXPONENT = 42,                    // EXPONENT
+            S_FLOOR = 43,                       // FLOOR
+            S_GT = 44,                          // GT
+            S_GTE = 45,                         // GTE
+            S_ID = 46,                          // ID
+            S_INDEX_OF_BYTES = 47,              // INDEX_OF_BYTES
+            S_INDEX_OF_CP = 48,                 // INDEX_OF_CP
+            S_INT_NEGATIVE_ONE = 49,            // "-1 (int)"
+            S_INT_ONE = 50,                     // "1 (int)"
+            S_INT_ZERO = 51,                    // "zero (int)"
+            S_LITERAL = 52,                     // LITERAL
+            S_LN = 53,                          // LN
+            S_LOG = 54,                         // LOG
+            S_LOGTEN = 55,                      // LOGTEN
+            S_LONG_NEGATIVE_ONE = 56,           // "-1 (long)"
+            S_LONG_ONE = 57,                    // "1 (long)"
+            S_LONG_ZERO = 58,                   // "zero (long)"
+            S_LT = 59,                          // LT
+            S_LTE = 60,                         // LTE
+            S_LTRIM = 61,                       // LTRIM
+            S_META = 62,                        // META
+            S_MOD = 63,                         // MOD
+            S_MULTIPLY = 64,                    // MULTIPLY
+            S_NE = 65,                          // NE
+            S_NOT = 66,                         // NOT
+            S_OR = 67,                          // OR
+            S_POW = 68,                         // POW
+            S_RAND_VAL = 69,                    // "randVal"
+            S_REGEX_FIND = 70,                  // REGEX_FIND
+            S_REGEX_FIND_ALL = 71,              // REGEX_FIND_ALL
+            S_REGEX_MATCH = 72,                 // REGEX_MATCH
+            S_REPLACE_ALL = 73,                 // REPLACE_ALL
+            S_REPLACE_ONE = 74,                 // REPLACE_ONE
+            S_ROUND = 75,                       // ROUND
+            S_RTRIM = 76,                       // RTRIM
+            S_SPLIT = 77,                       // SPLIT
+            S_SQRT = 78,                        // SQRT
+            S_STAGE_INHIBIT_OPTIMIZATION = 79,  // STAGE_INHIBIT_OPTIMIZATION
+            S_STAGE_LIMIT = 80,                 // STAGE_LIMIT
+            S_STAGE_PROJECT = 81,               // STAGE_PROJECT
+            S_STAGE_SAMPLE = 82,                // STAGE_SAMPLE
+            S_STAGE_SKIP = 83,                  // STAGE_SKIP
+            S_STAGE_UNION_WITH = 84,            // STAGE_UNION_WITH
+            S_START_ARRAY = 85,                 // "array"
+            S_START_OBJECT = 86,                // "object"
+            S_STR_CASE_CMP = 87,                // STR_CASE_CMP
+            S_STR_LEN_BYTES = 88,               // STR_LEN_BYTES
+            S_STR_LEN_CP = 89,                  // STR_LEN_CP
+            S_SUBSTR = 90,                      // SUBSTR
+            S_SUBSTR_BYTES = 91,                // SUBSTR_BYTES
+            S_SUBSTR_CP = 92,                   // SUBSTR_CP
+            S_SUBTRACT = 93,                    // SUBTRACT
+            S_TEXT_SCORE = 94,                  // "textScore"
+            S_TO_BOOL = 95,                     // TO_BOOL
+            S_TO_DATE = 96,                     // TO_DATE
+            S_TO_DECIMAL = 97,                  // TO_DECIMAL
+            S_TO_DOUBLE = 98,                   // TO_DOUBLE
+            S_TO_INT = 99,                      // TO_INT
+            S_TO_LONG = 100,                    // TO_LONG
+            S_TO_LOWER = 101,                   // TO_LOWER
+            S_TO_OBJECT_ID = 102,               // TO_OBJECT_ID
+            S_TO_STRING = 103,                  // TO_STRING
+            S_TO_UPPER = 104,                   // TO_UPPER
+            S_TRIM = 105,                       // TRIM
+            S_TRUNC = 106,                      // TRUNC
+            S_TYPE = 107,                       // TYPE
+            S_FIELDNAME = 108,                  // "fieldname"
+            S_STRING = 109,                     // "string"
+            S_BINARY = 110,                     // "BinData"
+            S_UNDEFINED = 111,                  // "undefined"
+            S_OBJECT_ID = 112,                  // "ObjectID"
+            S_DATE_LITERAL = 113,               // "Date"
+            S_JSNULL = 114,                     // "null"
+            S_REGEX = 115,                      // "regex"
+            S_DB_POINTER = 116,                 // "dbPointer"
+            S_JAVASCRIPT = 117,                 // "Code"
+            S_SYMBOL = 118,                     // "Symbol"
+            S_JAVASCRIPT_W_SCOPE = 119,         // "CodeWScope"
+            S_INT_OTHER = 120,                  // "arbitrary integer"
+            S_LONG_OTHER = 121,                 // "arbitrary long"
+            S_DOUBLE_OTHER = 122,               // "arbitrary double"
+            S_DECIMAL_OTHER = 123,              // "arbitrary decimal"
+            S_TIMESTAMP = 124,                  // "Timestamp"
+            S_MIN_KEY = 125,                    // "minKey"
+            S_MAX_KEY = 126,                    // "maxKey"
+            S_DOLLAR_STRING = 127,              // "$-prefixed string"
+            S_DOLLAR_DOLLAR_STRING = 128,       // "$$-prefixed string"
+            S_DOLLAR_PREF_FIELDNAME = 129,      // "$-prefixed fieldname"
+            S_START_PIPELINE = 130,             // START_PIPELINE
+            S_START_MATCH = 131,                // START_MATCH
+            S_START_SORT = 132,                 // START_SORT
+            S_YYACCEPT = 133,                   // $accept
+            S_projectionFieldname = 134,        // projectionFieldname
+            S_expressionFieldname = 135,        // expressionFieldname
+            S_stageAsUserFieldname = 136,       // stageAsUserFieldname
+            S_filterFieldname = 137,            // filterFieldname
+            S_argAsUserFieldname = 138,         // argAsUserFieldname
+            S_aggExprAsUserFieldname = 139,     // aggExprAsUserFieldname
+            S_invariableUserFieldname = 140,    // invariableUserFieldname
+            S_idAsUserFieldname = 141,          // idAsUserFieldname
+            S_valueFieldname = 142,             // valueFieldname
+            S_projectField = 143,               // projectField
+            S_expressionField = 144,            // expressionField
+            S_valueField = 145,                 // valueField
+            S_filterField = 146,                // filterField
+            S_dbPointer = 147,                  // dbPointer
+            S_javascript = 148,                 // javascript
+            S_symbol = 149,                     // symbol
+            S_javascriptWScope = 150,           // javascriptWScope
+            S_int = 151,                        // int
+            S_timestamp = 152,                  // timestamp
+            S_long = 153,                       // long
+            S_double = 154,                     // double
+            S_decimal = 155,                    // decimal
+            S_minKey = 156,                     // minKey
+            S_maxKey = 157,                     // maxKey
+            S_value = 158,                      // value
+            S_string = 159,                     // string
+            S_fieldPath = 160,                  // fieldPath
+            S_binary = 161,                     // binary
+            S_undefined = 162,                  // undefined
+            S_objectId = 163,                   // objectId
+            S_bool = 164,                       // bool
+            S_date = 165,                       // date
+            S_null = 166,                       // null
+            S_regex = 167,                      // regex
+            S_simpleValue = 168,                // simpleValue
+            S_compoundValue = 169,              // compoundValue
+            S_valueArray = 170,                 // valueArray
+            S_valueObject = 171,                // valueObject
+            S_valueFields = 172,                // valueFields
+            S_variable = 173,                   // variable
+            S_pipeline = 174,                   // pipeline
+            S_stageList = 175,                  // stageList
+            S_stage = 176,                      // stage
+            S_inhibitOptimization = 177,        // inhibitOptimization
+            S_unionWith = 178,                  // unionWith
+            S_skip = 179,                       // skip
+            S_limit = 180,                      // limit
+            S_project = 181,                    // project
+            S_sample = 182,                     // sample
+            S_projectFields = 183,              // projectFields
+            S_projection = 184,                 // projection
+            S_num = 185,                        // num
+            S_expression = 186,                 // expression
+            S_compoundExpression = 187,         // compoundExpression
+            S_exprFixedTwoArg = 188,            // exprFixedTwoArg
+            S_expressionArray = 189,            // expressionArray
+            S_expressionObject = 190,           // expressionObject
+            S_expressionFields = 191,           // expressionFields
+            S_maths = 192,                      // maths
+            S_add = 193,                        // add
+            S_atan2 = 194,                      // atan2
+            S_boolExps = 195,                   // boolExps
+            S_and = 196,                        // and
+            S_or = 197,                         // or
+            S_not = 198,                        // not
+            S_literalEscapes = 199,             // literalEscapes
+            S_const = 200,                      // const
+            S_literal = 201,                    // literal
+            S_stringExps = 202,                 // stringExps
+            S_concat = 203,                     // concat
+            S_dateFromString = 204,             // dateFromString
+            S_dateToString = 205,               // dateToString
+            S_indexOfBytes = 206,               // indexOfBytes
+            S_indexOfCP = 207,                  // indexOfCP
+            S_ltrim = 208,                      // ltrim
+            S_regexFind = 209,                  // regexFind
+            S_regexFindAll = 210,               // regexFindAll
+            S_regexMatch = 211,                 // regexMatch
+            S_regexArgs = 212,                  // regexArgs
+            S_replaceOne = 213,                 // replaceOne
+            S_replaceAll = 214,                 // replaceAll
+            S_rtrim = 215,                      // rtrim
+            S_split = 216,                      // split
+            S_strLenBytes = 217,                // strLenBytes
+            S_strLenCP = 218,                   // strLenCP
+            S_strcasecmp = 219,                 // strcasecmp
+            S_substr = 220,                     // substr
+            S_substrBytes = 221,                // substrBytes
+            S_substrCP = 222,                   // substrCP
+            S_toLower = 223,                    // toLower
+            S_toUpper = 224,                    // toUpper
+            S_trim = 225,                       // trim
+            S_compExprs = 226,                  // compExprs
+            S_cmp = 227,                        // cmp
+            S_eq = 228,                         // eq
+            S_gt = 229,                         // gt
+            S_gte = 230,                        // gte
+            S_lt = 231,                         // lt
+            S_lte = 232,                        // lte
+            S_ne = 233,                         // ne
+            S_typeExpression = 234,             // typeExpression
+            S_convert = 235,                    // convert
+            S_toBool = 236,                     // toBool
+            S_toDate = 237,                     // toDate
+            S_toDecimal = 238,                  // toDecimal
+            S_toDouble = 239,                   // toDouble
+            S_toInt = 240,                      // toInt
+            S_toLong = 241,                     // toLong
+            S_toObjectId = 242,                 // toObjectId
+            S_toString = 243,                   // toString
+            S_type = 244,                       // type
+            S_abs = 245,                        // abs
+            S_ceil = 246,                       // ceil
+            S_divide = 247,                     // divide
+            S_exponent = 248,                   // exponent
+            S_floor = 249,                      // floor
+            S_ln = 250,                         // ln
+            S_log = 251,                        // log
+            S_logten = 252,                     // logten
+            S_mod = 253,                        // mod
+            S_multiply = 254,                   // multiply
+            S_pow = 255,                        // pow
+            S_round = 256,                      // round
+            S_sqrt = 257,                       // sqrt
+            S_subtract = 258,                   // subtract
+            S_trunc = 259,                      // trunc
+            S_onErrorArg = 260,                 // onErrorArg
+            S_onNullArg = 261,                  // onNullArg
+            S_formatArg = 262,                  // formatArg
+            S_timezoneArg = 263,                // timezoneArg
+            S_charsArg = 264,                   // charsArg
+            S_optionsArg = 265,                 // optionsArg
+            S_expressions = 266,                // expressions
+            S_values = 267,                     // values
+            S_exprZeroToTwo = 268,              // exprZeroToTwo
+            S_matchExpression = 269,            // matchExpression
+            S_filterFields = 270,               // filterFields
+            S_filterVal = 271,                  // filterVal
+            S_sortSpecs = 272,                  // sortSpecs
+            S_specList = 273,                   // specList
+            S_metaSort = 274,                   // metaSort
+            S_oneOrNegOne = 275,                // oneOrNegOne
+            S_metaSortKeyword = 276,            // metaSortKeyword
+            S_sortSpec = 277,                   // sortSpec
+            S_start = 278,                      // start
+            S_START_ORDERED_OBJECT = 279,       // START_ORDERED_OBJECT
+            S_280_1 = 280                       // $@1
+        };
+    };
 
-    /// The symbol type number to denote an empty symbol.
-    enum { empty_symbol = -2 };
+    /// (Internal) symbol kind.
+    typedef symbol_kind::symbol_kind_type symbol_kind_type;
 
-    /// Internal symbol number for tokens (subsumed by symbol_number_type).
-    typedef signed char token_number_type;
+    /// The number of tokens.
+    static const symbol_kind_type YYNTOKENS = symbol_kind::YYNTOKENS;
 
     /// A complete symbol.
     ///
-    /// Expects its Base type to provide access to the symbol type
-    /// via type_get ().
+    /// Expects its Base type to provide access to the symbol kind
+    /// via kind ().
     ///
     /// Provide access to semantic value and location.
     template <typename Base>
@@ -746,7 +1069,245 @@ public:
 
 #if 201103L <= YY_CPLUSPLUS
         /// Move constructor.
-        basic_symbol(basic_symbol&& that);
+        basic_symbol(basic_symbol&& that)
+            : Base(std::move(that)), value(), location(std::move(that.location)) {
+            switch (this->kind()) {
+                case symbol_kind::S_BINARY:  // "BinData"
+                    value.move<BSONBinData>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_JAVASCRIPT:  // "Code"
+                    value.move<BSONCode>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_JAVASCRIPT_W_SCOPE:  // "CodeWScope"
+                    value.move<BSONCodeWScope>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_DB_POINTER:  // "dbPointer"
+                    value.move<BSONDBRef>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_REGEX:  // "regex"
+                    value.move<BSONRegEx>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_SYMBOL:  // "Symbol"
+                    value.move<BSONSymbol>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_dbPointer:            // dbPointer
+                case symbol_kind::S_javascript:           // javascript
+                case symbol_kind::S_symbol:               // symbol
+                case symbol_kind::S_javascriptWScope:     // javascriptWScope
+                case symbol_kind::S_int:                  // int
+                case symbol_kind::S_timestamp:            // timestamp
+                case symbol_kind::S_long:                 // long
+                case symbol_kind::S_double:               // double
+                case symbol_kind::S_decimal:              // decimal
+                case symbol_kind::S_minKey:               // minKey
+                case symbol_kind::S_maxKey:               // maxKey
+                case symbol_kind::S_value:                // value
+                case symbol_kind::S_string:               // string
+                case symbol_kind::S_fieldPath:            // fieldPath
+                case symbol_kind::S_binary:               // binary
+                case symbol_kind::S_undefined:            // undefined
+                case symbol_kind::S_objectId:             // objectId
+                case symbol_kind::S_bool:                 // bool
+                case symbol_kind::S_date:                 // date
+                case symbol_kind::S_null:                 // null
+                case symbol_kind::S_regex:                // regex
+                case symbol_kind::S_simpleValue:          // simpleValue
+                case symbol_kind::S_compoundValue:        // compoundValue
+                case symbol_kind::S_valueArray:           // valueArray
+                case symbol_kind::S_valueObject:          // valueObject
+                case symbol_kind::S_valueFields:          // valueFields
+                case symbol_kind::S_variable:             // variable
+                case symbol_kind::S_pipeline:             // pipeline
+                case symbol_kind::S_stageList:            // stageList
+                case symbol_kind::S_stage:                // stage
+                case symbol_kind::S_inhibitOptimization:  // inhibitOptimization
+                case symbol_kind::S_unionWith:            // unionWith
+                case symbol_kind::S_skip:                 // skip
+                case symbol_kind::S_limit:                // limit
+                case symbol_kind::S_project:              // project
+                case symbol_kind::S_sample:               // sample
+                case symbol_kind::S_projectFields:        // projectFields
+                case symbol_kind::S_projection:           // projection
+                case symbol_kind::S_num:                  // num
+                case symbol_kind::S_expression:           // expression
+                case symbol_kind::S_compoundExpression:   // compoundExpression
+                case symbol_kind::S_exprFixedTwoArg:      // exprFixedTwoArg
+                case symbol_kind::S_expressionArray:      // expressionArray
+                case symbol_kind::S_expressionObject:     // expressionObject
+                case symbol_kind::S_expressionFields:     // expressionFields
+                case symbol_kind::S_maths:                // maths
+                case symbol_kind::S_add:                  // add
+                case symbol_kind::S_atan2:                // atan2
+                case symbol_kind::S_boolExps:             // boolExps
+                case symbol_kind::S_and:                  // and
+                case symbol_kind::S_or:                   // or
+                case symbol_kind::S_not:                  // not
+                case symbol_kind::S_literalEscapes:       // literalEscapes
+                case symbol_kind::S_const:                // const
+                case symbol_kind::S_literal:              // literal
+                case symbol_kind::S_stringExps:           // stringExps
+                case symbol_kind::S_concat:               // concat
+                case symbol_kind::S_dateFromString:       // dateFromString
+                case symbol_kind::S_dateToString:         // dateToString
+                case symbol_kind::S_indexOfBytes:         // indexOfBytes
+                case symbol_kind::S_indexOfCP:            // indexOfCP
+                case symbol_kind::S_ltrim:                // ltrim
+                case symbol_kind::S_regexFind:            // regexFind
+                case symbol_kind::S_regexFindAll:         // regexFindAll
+                case symbol_kind::S_regexMatch:           // regexMatch
+                case symbol_kind::S_regexArgs:            // regexArgs
+                case symbol_kind::S_replaceOne:           // replaceOne
+                case symbol_kind::S_replaceAll:           // replaceAll
+                case symbol_kind::S_rtrim:                // rtrim
+                case symbol_kind::S_split:                // split
+                case symbol_kind::S_strLenBytes:          // strLenBytes
+                case symbol_kind::S_strLenCP:             // strLenCP
+                case symbol_kind::S_strcasecmp:           // strcasecmp
+                case symbol_kind::S_substr:               // substr
+                case symbol_kind::S_substrBytes:          // substrBytes
+                case symbol_kind::S_substrCP:             // substrCP
+                case symbol_kind::S_toLower:              // toLower
+                case symbol_kind::S_toUpper:              // toUpper
+                case symbol_kind::S_trim:                 // trim
+                case symbol_kind::S_compExprs:            // compExprs
+                case symbol_kind::S_cmp:                  // cmp
+                case symbol_kind::S_eq:                   // eq
+                case symbol_kind::S_gt:                   // gt
+                case symbol_kind::S_gte:                  // gte
+                case symbol_kind::S_lt:                   // lt
+                case symbol_kind::S_lte:                  // lte
+                case symbol_kind::S_ne:                   // ne
+                case symbol_kind::S_typeExpression:       // typeExpression
+                case symbol_kind::S_convert:              // convert
+                case symbol_kind::S_toBool:               // toBool
+                case symbol_kind::S_toDate:               // toDate
+                case symbol_kind::S_toDecimal:            // toDecimal
+                case symbol_kind::S_toDouble:             // toDouble
+                case symbol_kind::S_toInt:                // toInt
+                case symbol_kind::S_toLong:               // toLong
+                case symbol_kind::S_toObjectId:           // toObjectId
+                case symbol_kind::S_toString:             // toString
+                case symbol_kind::S_type:                 // type
+                case symbol_kind::S_abs:                  // abs
+                case symbol_kind::S_ceil:                 // ceil
+                case symbol_kind::S_divide:               // divide
+                case symbol_kind::S_exponent:             // exponent
+                case symbol_kind::S_floor:                // floor
+                case symbol_kind::S_ln:                   // ln
+                case symbol_kind::S_log:                  // log
+                case symbol_kind::S_logten:               // logten
+                case symbol_kind::S_mod:                  // mod
+                case symbol_kind::S_multiply:             // multiply
+                case symbol_kind::S_pow:                  // pow
+                case symbol_kind::S_round:                // round
+                case symbol_kind::S_sqrt:                 // sqrt
+                case symbol_kind::S_subtract:             // subtract
+                case symbol_kind::S_trunc:                // trunc
+                case symbol_kind::S_matchExpression:      // matchExpression
+                case symbol_kind::S_filterFields:         // filterFields
+                case symbol_kind::S_filterVal:            // filterVal
+                case symbol_kind::S_sortSpecs:            // sortSpecs
+                case symbol_kind::S_specList:             // specList
+                case symbol_kind::S_metaSort:             // metaSort
+                case symbol_kind::S_oneOrNegOne:          // oneOrNegOne
+                case symbol_kind::S_metaSortKeyword:      // metaSortKeyword
+                    value.move<CNode>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_projectionFieldname:      // projectionFieldname
+                case symbol_kind::S_expressionFieldname:      // expressionFieldname
+                case symbol_kind::S_stageAsUserFieldname:     // stageAsUserFieldname
+                case symbol_kind::S_filterFieldname:          // filterFieldname
+                case symbol_kind::S_argAsUserFieldname:       // argAsUserFieldname
+                case symbol_kind::S_aggExprAsUserFieldname:   // aggExprAsUserFieldname
+                case symbol_kind::S_invariableUserFieldname:  // invariableUserFieldname
+                case symbol_kind::S_idAsUserFieldname:        // idAsUserFieldname
+                case symbol_kind::S_valueFieldname:           // valueFieldname
+                    value.move<CNode::Fieldname>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_DATE_LITERAL:  // "Date"
+                    value.move<Date_t>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_DECIMAL_OTHER:  // "arbitrary decimal"
+                    value.move<Decimal128>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_OBJECT_ID:  // "ObjectID"
+                    value.move<OID>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_TIMESTAMP:  // "Timestamp"
+                    value.move<Timestamp>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_MAX_KEY:  // "maxKey"
+                    value.move<UserMaxKey>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_MIN_KEY:  // "minKey"
+                    value.move<UserMinKey>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_JSNULL:  // "null"
+                    value.move<UserNull>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_UNDEFINED:  // "undefined"
+                    value.move<UserUndefined>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_DOUBLE_OTHER:  // "arbitrary double"
+                    value.move<double>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_INT_OTHER:  // "arbitrary integer"
+                    value.move<int>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_LONG_OTHER:  // "arbitrary long"
+                    value.move<long long>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_projectField:     // projectField
+                case symbol_kind::S_expressionField:  // expressionField
+                case symbol_kind::S_valueField:       // valueField
+                case symbol_kind::S_filterField:      // filterField
+                case symbol_kind::S_onErrorArg:       // onErrorArg
+                case symbol_kind::S_onNullArg:        // onNullArg
+                case symbol_kind::S_formatArg:        // formatArg
+                case symbol_kind::S_timezoneArg:      // timezoneArg
+                case symbol_kind::S_charsArg:         // charsArg
+                case symbol_kind::S_optionsArg:       // optionsArg
+                case symbol_kind::S_sortSpec:         // sortSpec
+                    value.move<std::pair<CNode::Fieldname, CNode>>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_FIELDNAME:              // "fieldname"
+                case symbol_kind::S_STRING:                 // "string"
+                case symbol_kind::S_DOLLAR_STRING:          // "$-prefixed string"
+                case symbol_kind::S_DOLLAR_DOLLAR_STRING:   // "$$-prefixed string"
+                case symbol_kind::S_DOLLAR_PREF_FIELDNAME:  // "$-prefixed fieldname"
+                    value.move<std::string>(std::move(that.value));
+                    break;
+
+                case symbol_kind::S_expressions:    // expressions
+                case symbol_kind::S_values:         // values
+                case symbol_kind::S_exprZeroToTwo:  // exprZeroToTwo
+                    value.move<std::vector<CNode>>(std::move(that.value));
+                    break;
+
+                default:
+                    break;
+            }
+        }
 #endif
 
         /// Copy constructor.
@@ -928,239 +1489,245 @@ public:
         /// Destroy contents, and record that is empty.
         void clear() {
             // User destructor.
-            symbol_number_type yytype = this->type_get();
+            symbol_kind_type yykind = this->kind();
             basic_symbol<Base>& yysym = *this;
             (void)yysym;
-            switch (yytype) {
+            switch (yykind) {
                 default:
                     break;
             }
 
-            // Type destructor.
-            switch (yytype) {
-                case 99:  // "BinData"
+            // Value type destructor.
+            switch (yykind) {
+                case symbol_kind::S_BINARY:  // "BinData"
                     value.template destroy<BSONBinData>();
                     break;
 
-                case 106:  // "Code"
+                case symbol_kind::S_JAVASCRIPT:  // "Code"
                     value.template destroy<BSONCode>();
                     break;
 
-                case 108:  // "CodeWScope"
+                case symbol_kind::S_JAVASCRIPT_W_SCOPE:  // "CodeWScope"
                     value.template destroy<BSONCodeWScope>();
                     break;
 
-                case 105:  // "dbPointer"
+                case symbol_kind::S_DB_POINTER:  // "dbPointer"
                     value.template destroy<BSONDBRef>();
                     break;
 
-                case 104:  // "regex"
+                case symbol_kind::S_REGEX:  // "regex"
                     value.template destroy<BSONRegEx>();
                     break;
 
-                case 107:  // "Symbol"
+                case symbol_kind::S_SYMBOL:  // "Symbol"
                     value.template destroy<BSONSymbol>();
                     break;
 
-                case 135:  // dbPointer
-                case 136:  // javascript
-                case 137:  // symbol
-                case 138:  // javascriptWScope
-                case 139:  // int
-                case 140:  // timestamp
-                case 141:  // long
-                case 142:  // double
-                case 143:  // decimal
-                case 144:  // minKey
-                case 145:  // maxKey
-                case 146:  // value
-                case 147:  // string
-                case 148:  // fieldPath
-                case 149:  // binary
-                case 150:  // undefined
-                case 151:  // objectId
-                case 152:  // bool
-                case 153:  // date
-                case 154:  // null
-                case 155:  // regex
-                case 156:  // simpleValue
-                case 157:  // compoundValue
-                case 158:  // valueArray
-                case 159:  // valueObject
-                case 160:  // valueFields
-                case 161:  // variable
-                case 162:  // pipeline
-                case 163:  // stageList
-                case 164:  // stage
-                case 165:  // inhibitOptimization
-                case 166:  // unionWith
-                case 167:  // skip
-                case 168:  // limit
-                case 169:  // project
-                case 170:  // sample
-                case 171:  // projectFields
-                case 172:  // projection
-                case 173:  // num
-                case 174:  // expression
-                case 175:  // compoundExpression
-                case 176:  // exprFixedTwoArg
-                case 177:  // expressionArray
-                case 178:  // expressionObject
-                case 179:  // expressionFields
-                case 180:  // maths
-                case 181:  // add
-                case 182:  // atan2
-                case 183:  // boolExps
-                case 184:  // and
-                case 185:  // or
-                case 186:  // not
-                case 187:  // literalEscapes
-                case 188:  // const
-                case 189:  // literal
-                case 190:  // stringExps
-                case 191:  // concat
-                case 192:  // dateFromString
-                case 193:  // dateToString
-                case 194:  // indexOfBytes
-                case 195:  // indexOfCP
-                case 196:  // ltrim
-                case 197:  // regexFind
-                case 198:  // regexFindAll
-                case 199:  // regexMatch
-                case 200:  // regexArgs
-                case 201:  // replaceOne
-                case 202:  // replaceAll
-                case 203:  // rtrim
-                case 204:  // split
-                case 205:  // strLenBytes
-                case 206:  // strLenCP
-                case 207:  // strcasecmp
-                case 208:  // substr
-                case 209:  // substrBytes
-                case 210:  // substrCP
-                case 211:  // toLower
-                case 212:  // toUpper
-                case 213:  // trim
-                case 214:  // compExprs
-                case 215:  // cmp
-                case 216:  // eq
-                case 217:  // gt
-                case 218:  // gte
-                case 219:  // lt
-                case 220:  // lte
-                case 221:  // ne
-                case 222:  // typeExpression
-                case 223:  // convert
-                case 224:  // toBool
-                case 225:  // toDate
-                case 226:  // toDecimal
-                case 227:  // toDouble
-                case 228:  // toInt
-                case 229:  // toLong
-                case 230:  // toObjectId
-                case 231:  // toString
-                case 232:  // type
-                case 233:  // abs
-                case 234:  // ceil
-                case 235:  // divide
-                case 236:  // exponent
-                case 237:  // floor
-                case 238:  // ln
-                case 239:  // log
-                case 240:  // logten
-                case 241:  // mod
-                case 242:  // multiply
-                case 243:  // pow
-                case 244:  // round
-                case 245:  // sqrt
-                case 246:  // subtract
-                case 247:  // trunc
-                case 257:  // matchExpression
-                case 258:  // filterFields
-                case 259:  // filterVal
+                case symbol_kind::S_dbPointer:            // dbPointer
+                case symbol_kind::S_javascript:           // javascript
+                case symbol_kind::S_symbol:               // symbol
+                case symbol_kind::S_javascriptWScope:     // javascriptWScope
+                case symbol_kind::S_int:                  // int
+                case symbol_kind::S_timestamp:            // timestamp
+                case symbol_kind::S_long:                 // long
+                case symbol_kind::S_double:               // double
+                case symbol_kind::S_decimal:              // decimal
+                case symbol_kind::S_minKey:               // minKey
+                case symbol_kind::S_maxKey:               // maxKey
+                case symbol_kind::S_value:                // value
+                case symbol_kind::S_string:               // string
+                case symbol_kind::S_fieldPath:            // fieldPath
+                case symbol_kind::S_binary:               // binary
+                case symbol_kind::S_undefined:            // undefined
+                case symbol_kind::S_objectId:             // objectId
+                case symbol_kind::S_bool:                 // bool
+                case symbol_kind::S_date:                 // date
+                case symbol_kind::S_null:                 // null
+                case symbol_kind::S_regex:                // regex
+                case symbol_kind::S_simpleValue:          // simpleValue
+                case symbol_kind::S_compoundValue:        // compoundValue
+                case symbol_kind::S_valueArray:           // valueArray
+                case symbol_kind::S_valueObject:          // valueObject
+                case symbol_kind::S_valueFields:          // valueFields
+                case symbol_kind::S_variable:             // variable
+                case symbol_kind::S_pipeline:             // pipeline
+                case symbol_kind::S_stageList:            // stageList
+                case symbol_kind::S_stage:                // stage
+                case symbol_kind::S_inhibitOptimization:  // inhibitOptimization
+                case symbol_kind::S_unionWith:            // unionWith
+                case symbol_kind::S_skip:                 // skip
+                case symbol_kind::S_limit:                // limit
+                case symbol_kind::S_project:              // project
+                case symbol_kind::S_sample:               // sample
+                case symbol_kind::S_projectFields:        // projectFields
+                case symbol_kind::S_projection:           // projection
+                case symbol_kind::S_num:                  // num
+                case symbol_kind::S_expression:           // expression
+                case symbol_kind::S_compoundExpression:   // compoundExpression
+                case symbol_kind::S_exprFixedTwoArg:      // exprFixedTwoArg
+                case symbol_kind::S_expressionArray:      // expressionArray
+                case symbol_kind::S_expressionObject:     // expressionObject
+                case symbol_kind::S_expressionFields:     // expressionFields
+                case symbol_kind::S_maths:                // maths
+                case symbol_kind::S_add:                  // add
+                case symbol_kind::S_atan2:                // atan2
+                case symbol_kind::S_boolExps:             // boolExps
+                case symbol_kind::S_and:                  // and
+                case symbol_kind::S_or:                   // or
+                case symbol_kind::S_not:                  // not
+                case symbol_kind::S_literalEscapes:       // literalEscapes
+                case symbol_kind::S_const:                // const
+                case symbol_kind::S_literal:              // literal
+                case symbol_kind::S_stringExps:           // stringExps
+                case symbol_kind::S_concat:               // concat
+                case symbol_kind::S_dateFromString:       // dateFromString
+                case symbol_kind::S_dateToString:         // dateToString
+                case symbol_kind::S_indexOfBytes:         // indexOfBytes
+                case symbol_kind::S_indexOfCP:            // indexOfCP
+                case symbol_kind::S_ltrim:                // ltrim
+                case symbol_kind::S_regexFind:            // regexFind
+                case symbol_kind::S_regexFindAll:         // regexFindAll
+                case symbol_kind::S_regexMatch:           // regexMatch
+                case symbol_kind::S_regexArgs:            // regexArgs
+                case symbol_kind::S_replaceOne:           // replaceOne
+                case symbol_kind::S_replaceAll:           // replaceAll
+                case symbol_kind::S_rtrim:                // rtrim
+                case symbol_kind::S_split:                // split
+                case symbol_kind::S_strLenBytes:          // strLenBytes
+                case symbol_kind::S_strLenCP:             // strLenCP
+                case symbol_kind::S_strcasecmp:           // strcasecmp
+                case symbol_kind::S_substr:               // substr
+                case symbol_kind::S_substrBytes:          // substrBytes
+                case symbol_kind::S_substrCP:             // substrCP
+                case symbol_kind::S_toLower:              // toLower
+                case symbol_kind::S_toUpper:              // toUpper
+                case symbol_kind::S_trim:                 // trim
+                case symbol_kind::S_compExprs:            // compExprs
+                case symbol_kind::S_cmp:                  // cmp
+                case symbol_kind::S_eq:                   // eq
+                case symbol_kind::S_gt:                   // gt
+                case symbol_kind::S_gte:                  // gte
+                case symbol_kind::S_lt:                   // lt
+                case symbol_kind::S_lte:                  // lte
+                case symbol_kind::S_ne:                   // ne
+                case symbol_kind::S_typeExpression:       // typeExpression
+                case symbol_kind::S_convert:              // convert
+                case symbol_kind::S_toBool:               // toBool
+                case symbol_kind::S_toDate:               // toDate
+                case symbol_kind::S_toDecimal:            // toDecimal
+                case symbol_kind::S_toDouble:             // toDouble
+                case symbol_kind::S_toInt:                // toInt
+                case symbol_kind::S_toLong:               // toLong
+                case symbol_kind::S_toObjectId:           // toObjectId
+                case symbol_kind::S_toString:             // toString
+                case symbol_kind::S_type:                 // type
+                case symbol_kind::S_abs:                  // abs
+                case symbol_kind::S_ceil:                 // ceil
+                case symbol_kind::S_divide:               // divide
+                case symbol_kind::S_exponent:             // exponent
+                case symbol_kind::S_floor:                // floor
+                case symbol_kind::S_ln:                   // ln
+                case symbol_kind::S_log:                  // log
+                case symbol_kind::S_logten:               // logten
+                case symbol_kind::S_mod:                  // mod
+                case symbol_kind::S_multiply:             // multiply
+                case symbol_kind::S_pow:                  // pow
+                case symbol_kind::S_round:                // round
+                case symbol_kind::S_sqrt:                 // sqrt
+                case symbol_kind::S_subtract:             // subtract
+                case symbol_kind::S_trunc:                // trunc
+                case symbol_kind::S_matchExpression:      // matchExpression
+                case symbol_kind::S_filterFields:         // filterFields
+                case symbol_kind::S_filterVal:            // filterVal
+                case symbol_kind::S_sortSpecs:            // sortSpecs
+                case symbol_kind::S_specList:             // specList
+                case symbol_kind::S_metaSort:             // metaSort
+                case symbol_kind::S_oneOrNegOne:          // oneOrNegOne
+                case symbol_kind::S_metaSortKeyword:      // metaSortKeyword
                     value.template destroy<CNode>();
                     break;
 
-                case 122:  // projectionFieldname
-                case 123:  // expressionFieldname
-                case 124:  // stageAsUserFieldname
-                case 125:  // filterFieldname
-                case 126:  // argAsUserFieldname
-                case 127:  // aggExprAsUserFieldname
-                case 128:  // invariableUserFieldname
-                case 129:  // idAsUserFieldname
-                case 130:  // valueFieldname
+                case symbol_kind::S_projectionFieldname:      // projectionFieldname
+                case symbol_kind::S_expressionFieldname:      // expressionFieldname
+                case symbol_kind::S_stageAsUserFieldname:     // stageAsUserFieldname
+                case symbol_kind::S_filterFieldname:          // filterFieldname
+                case symbol_kind::S_argAsUserFieldname:       // argAsUserFieldname
+                case symbol_kind::S_aggExprAsUserFieldname:   // aggExprAsUserFieldname
+                case symbol_kind::S_invariableUserFieldname:  // invariableUserFieldname
+                case symbol_kind::S_idAsUserFieldname:        // idAsUserFieldname
+                case symbol_kind::S_valueFieldname:           // valueFieldname
                     value.template destroy<CNode::Fieldname>();
                     break;
 
-                case 102:  // "Date"
+                case symbol_kind::S_DATE_LITERAL:  // "Date"
                     value.template destroy<Date_t>();
                     break;
 
-                case 112:  // "non-zero decimal"
+                case symbol_kind::S_DECIMAL_OTHER:  // "arbitrary decimal"
                     value.template destroy<Decimal128>();
                     break;
 
-                case 101:  // "ObjectID"
+                case symbol_kind::S_OBJECT_ID:  // "ObjectID"
                     value.template destroy<OID>();
                     break;
 
-                case 113:  // "Timestamp"
+                case symbol_kind::S_TIMESTAMP:  // "Timestamp"
                     value.template destroy<Timestamp>();
                     break;
 
-                case 115:  // "maxKey"
+                case symbol_kind::S_MAX_KEY:  // "maxKey"
                     value.template destroy<UserMaxKey>();
                     break;
 
-                case 114:  // "minKey"
+                case symbol_kind::S_MIN_KEY:  // "minKey"
                     value.template destroy<UserMinKey>();
                     break;
 
-                case 103:  // "null"
+                case symbol_kind::S_JSNULL:  // "null"
                     value.template destroy<UserNull>();
                     break;
 
-                case 100:  // "undefined"
+                case symbol_kind::S_UNDEFINED:  // "undefined"
                     value.template destroy<UserUndefined>();
                     break;
 
-                case 111:  // "non-zero double"
+                case symbol_kind::S_DOUBLE_OTHER:  // "arbitrary double"
                     value.template destroy<double>();
                     break;
 
-                case 109:  // "non-zero integer"
+                case symbol_kind::S_INT_OTHER:  // "arbitrary integer"
                     value.template destroy<int>();
                     break;
 
-                case 110:  // "non-zero long"
+                case symbol_kind::S_LONG_OTHER:  // "arbitrary long"
                     value.template destroy<long long>();
                     break;
 
-                case 131:  // projectField
-                case 132:  // expressionField
-                case 133:  // valueField
-                case 134:  // filterField
-                case 248:  // onErrorArg
-                case 249:  // onNullArg
-                case 250:  // formatArg
-                case 251:  // timezoneArg
-                case 252:  // charsArg
-                case 253:  // optionsArg
+                case symbol_kind::S_projectField:     // projectField
+                case symbol_kind::S_expressionField:  // expressionField
+                case symbol_kind::S_valueField:       // valueField
+                case symbol_kind::S_filterField:      // filterField
+                case symbol_kind::S_onErrorArg:       // onErrorArg
+                case symbol_kind::S_onNullArg:        // onNullArg
+                case symbol_kind::S_formatArg:        // formatArg
+                case symbol_kind::S_timezoneArg:      // timezoneArg
+                case symbol_kind::S_charsArg:         // charsArg
+                case symbol_kind::S_optionsArg:       // optionsArg
+                case symbol_kind::S_sortSpec:         // sortSpec
                     value.template destroy<std::pair<CNode::Fieldname, CNode>>();
                     break;
 
-                case 97:   // "fieldname"
-                case 98:   // "string"
-                case 116:  // "$-prefixed string"
-                case 117:  // "$$-prefixed string"
-                case 118:  // "$-prefixed fieldname"
+                case symbol_kind::S_FIELDNAME:              // "fieldname"
+                case symbol_kind::S_STRING:                 // "string"
+                case symbol_kind::S_DOLLAR_STRING:          // "$-prefixed string"
+                case symbol_kind::S_DOLLAR_DOLLAR_STRING:   // "$$-prefixed string"
+                case symbol_kind::S_DOLLAR_PREF_FIELDNAME:  // "$-prefixed fieldname"
                     value.template destroy<std::string>();
                     break;
 
-                case 254:  // expressions
-                case 255:  // values
-                case 256:  // exprZeroToTwo
+                case symbol_kind::S_expressions:    // expressions
+                case symbol_kind::S_values:         // values
+                case symbol_kind::S_exprZeroToTwo:  // exprZeroToTwo
                     value.template destroy<std::vector<CNode>>();
                     break;
 
@@ -1171,6 +1738,14 @@ public:
             Base::clear();
         }
 
+        /// The user-facing name of this symbol.
+        std::string name() const YY_NOEXCEPT {
+            return PipelineParserGen::symbol_name(this->kind());
+        }
+
+        /// Backward compatibility (Bison 3.6).
+        symbol_kind_type type_get() const YY_NOEXCEPT;
+
         /// Whether empty.
         bool empty() const YY_NOEXCEPT;
 
@@ -1191,44 +1766,49 @@ public:
     };
 
     /// Type access provider for token (enum) based symbols.
-    struct by_type {
+    struct by_kind {
         /// Default constructor.
-        by_type();
+        by_kind();
 
 #if 201103L <= YY_CPLUSPLUS
         /// Move constructor.
-        by_type(by_type&& that);
+        by_kind(by_kind&& that);
 #endif
 
         /// Copy constructor.
-        by_type(const by_type& that);
+        by_kind(const by_kind& that);
 
-        /// The symbol type as needed by the constructor.
-        typedef token_type kind_type;
+        /// The symbol kind as needed by the constructor.
+        typedef token_kind_type kind_type;
 
         /// Constructor from (external) token numbers.
-        by_type(kind_type t);
+        by_kind(kind_type t);
 
         /// Record that this symbol is empty.
         void clear();
 
-        /// Steal the symbol type from \a that.
-        void move(by_type& that);
+        /// Steal the symbol kind from \a that.
+        void move(by_kind& that);
 
         /// The (internal) type number (corresponding to \a type).
         /// \a empty when empty.
-        symbol_number_type type_get() const YY_NOEXCEPT;
+        symbol_kind_type kind() const YY_NOEXCEPT;
 
-        /// The symbol type.
-        /// \a empty_symbol when empty.
-        /// An int, not token_number_type, to be able to store empty_symbol.
-        int type;
+        /// Backward compatibility (Bison 3.6).
+        symbol_kind_type type_get() const YY_NOEXCEPT;
+
+        /// The symbol kind.
+        /// \a S_YYEMPTY when empty.
+        symbol_kind_type kind_;
     };
 
+    /// Backward compatibility for a private implementation detail (Bison 3.6).
+    typedef by_kind by_type;
+
     /// "External" symbols: returned by the scanner.
-    struct symbol_type : basic_symbol<by_type> {
+    struct symbol_type : basic_symbol<by_kind> {
         /// Superclass.
-        typedef basic_symbol<by_type> super_type;
+        typedef basic_symbol<by_kind> super_type;
 
         /// Empty symbol.
         symbol_type() {}
@@ -1237,9 +1817,10 @@ public:
 #if 201103L <= YY_CPLUSPLUS
         symbol_type(int tok, location_type l) : super_type(token_type(tok), std::move(l)) {
             YY_ASSERT(
-                tok == token::END_OF_FILE || tok == token::ABS || tok == token::ADD ||
-                tok == token::AND || tok == token::ARG_CHARS || tok == token::ARG_COLL ||
-                tok == token::ARG_DATE || tok == token::ARG_DATE_STRING || tok == token::ARG_FIND ||
+                tok == token::END_OF_FILE || tok == token::YYerror || tok == token::YYUNDEF ||
+                tok == token::ABS || tok == token::ADD || tok == token::AND ||
+                tok == token::ARG_CHARS || tok == token::ARG_COLL || tok == token::ARG_DATE ||
+                tok == token::ARG_DATE_STRING || tok == token::ARG_FIND ||
                 tok == token::ARG_FORMAT || tok == token::ARG_INPUT || tok == token::ARG_ON_ERROR ||
                 tok == token::ARG_ON_NULL || tok == token::ARG_OPTIONS ||
                 tok == token::ARG_PIPELINE || tok == token::ARG_REGEX ||
@@ -1248,38 +1829,45 @@ public:
                 tok == token::BOOL_FALSE || tok == token::BOOL_TRUE || tok == token::CEIL ||
                 tok == token::CMP || tok == token::CONCAT || tok == token::CONST_EXPR ||
                 tok == token::CONVERT || tok == token::DATE_FROM_STRING ||
-                tok == token::DATE_TO_STRING || tok == token::DECIMAL_ZERO ||
-                tok == token::DIVIDE || tok == token::DOUBLE_ZERO || tok == token::END_ARRAY ||
-                tok == token::END_OBJECT || tok == token::EQ || tok == token::EXPONENT ||
-                tok == token::FLOOR || tok == token::GT || tok == token::GTE || tok == token::ID ||
+                tok == token::DATE_TO_STRING || tok == token::DECIMAL_NEGATIVE_ONE ||
+                tok == token::DECIMAL_ONE || tok == token::DECIMAL_ZERO || tok == token::DIVIDE ||
+                tok == token::DOUBLE_NEGATIVE_ONE || tok == token::DOUBLE_ONE ||
+                tok == token::DOUBLE_ZERO || tok == token::END_ARRAY || tok == token::END_OBJECT ||
+                tok == token::EQ || tok == token::EXPONENT || tok == token::FLOOR ||
+                tok == token::GT || tok == token::GTE || tok == token::ID ||
                 tok == token::INDEX_OF_BYTES || tok == token::INDEX_OF_CP ||
-                tok == token::INT_ZERO || tok == token::LITERAL || tok == token::LN ||
-                tok == token::LOG || tok == token::LOGTEN || tok == token::LONG_ZERO ||
-                tok == token::LT || tok == token::LTE || tok == token::LTRIM || tok == token::MOD ||
+                tok == token::INT_NEGATIVE_ONE || tok == token::INT_ONE || tok == token::INT_ZERO ||
+                tok == token::LITERAL || tok == token::LN || tok == token::LOG ||
+                tok == token::LOGTEN || tok == token::LONG_NEGATIVE_ONE || tok == token::LONG_ONE ||
+                tok == token::LONG_ZERO || tok == token::LT || tok == token::LTE ||
+                tok == token::LTRIM || tok == token::META || tok == token::MOD ||
                 tok == token::MULTIPLY || tok == token::NE || tok == token::NOT ||
-                tok == token::OR || tok == token::POW || tok == token::REGEX_FIND ||
-                tok == token::REGEX_FIND_ALL || tok == token::REGEX_MATCH ||
-                tok == token::REPLACE_ALL || tok == token::REPLACE_ONE || tok == token::ROUND ||
-                tok == token::RTRIM || tok == token::SPLIT || tok == token::SQRT ||
+                tok == token::OR || tok == token::POW || tok == token::RAND_VAL ||
+                tok == token::REGEX_FIND || tok == token::REGEX_FIND_ALL ||
+                tok == token::REGEX_MATCH || tok == token::REPLACE_ALL ||
+                tok == token::REPLACE_ONE || tok == token::ROUND || tok == token::RTRIM ||
+                tok == token::SPLIT || tok == token::SQRT ||
                 tok == token::STAGE_INHIBIT_OPTIMIZATION || tok == token::STAGE_LIMIT ||
                 tok == token::STAGE_PROJECT || tok == token::STAGE_SAMPLE ||
                 tok == token::STAGE_SKIP || tok == token::STAGE_UNION_WITH ||
                 tok == token::START_ARRAY || tok == token::START_OBJECT ||
                 tok == token::STR_CASE_CMP || tok == token::STR_LEN_BYTES ||
                 tok == token::STR_LEN_CP || tok == token::SUBSTR || tok == token::SUBSTR_BYTES ||
-                tok == token::SUBSTR_CP || tok == token::SUBTRACT || tok == token::TO_BOOL ||
-                tok == token::TO_DATE || tok == token::TO_DECIMAL || tok == token::TO_DOUBLE ||
-                tok == token::TO_INT || tok == token::TO_LONG || tok == token::TO_LOWER ||
-                tok == token::TO_OBJECT_ID || tok == token::TO_STRING || tok == token::TO_UPPER ||
-                tok == token::TRIM || tok == token::TRUNC || tok == token::TYPE ||
-                tok == token::START_PIPELINE || tok == token::START_MATCH);
+                tok == token::SUBSTR_CP || tok == token::SUBTRACT || tok == token::TEXT_SCORE ||
+                tok == token::TO_BOOL || tok == token::TO_DATE || tok == token::TO_DECIMAL ||
+                tok == token::TO_DOUBLE || tok == token::TO_INT || tok == token::TO_LONG ||
+                tok == token::TO_LOWER || tok == token::TO_OBJECT_ID || tok == token::TO_STRING ||
+                tok == token::TO_UPPER || tok == token::TRIM || tok == token::TRUNC ||
+                tok == token::TYPE || tok == token::START_PIPELINE || tok == token::START_MATCH ||
+                tok == token::START_SORT);
         }
 #else
         symbol_type(int tok, const location_type& l) : super_type(token_type(tok), l) {
             YY_ASSERT(
-                tok == token::END_OF_FILE || tok == token::ABS || tok == token::ADD ||
-                tok == token::AND || tok == token::ARG_CHARS || tok == token::ARG_COLL ||
-                tok == token::ARG_DATE || tok == token::ARG_DATE_STRING || tok == token::ARG_FIND ||
+                tok == token::END_OF_FILE || tok == token::YYerror || tok == token::YYUNDEF ||
+                tok == token::ABS || tok == token::ADD || tok == token::AND ||
+                tok == token::ARG_CHARS || tok == token::ARG_COLL || tok == token::ARG_DATE ||
+                tok == token::ARG_DATE_STRING || tok == token::ARG_FIND ||
                 tok == token::ARG_FORMAT || tok == token::ARG_INPUT || tok == token::ARG_ON_ERROR ||
                 tok == token::ARG_ON_NULL || tok == token::ARG_OPTIONS ||
                 tok == token::ARG_PIPELINE || tok == token::ARG_REGEX ||
@@ -1288,31 +1876,37 @@ public:
                 tok == token::BOOL_FALSE || tok == token::BOOL_TRUE || tok == token::CEIL ||
                 tok == token::CMP || tok == token::CONCAT || tok == token::CONST_EXPR ||
                 tok == token::CONVERT || tok == token::DATE_FROM_STRING ||
-                tok == token::DATE_TO_STRING || tok == token::DECIMAL_ZERO ||
-                tok == token::DIVIDE || tok == token::DOUBLE_ZERO || tok == token::END_ARRAY ||
-                tok == token::END_OBJECT || tok == token::EQ || tok == token::EXPONENT ||
-                tok == token::FLOOR || tok == token::GT || tok == token::GTE || tok == token::ID ||
+                tok == token::DATE_TO_STRING || tok == token::DECIMAL_NEGATIVE_ONE ||
+                tok == token::DECIMAL_ONE || tok == token::DECIMAL_ZERO || tok == token::DIVIDE ||
+                tok == token::DOUBLE_NEGATIVE_ONE || tok == token::DOUBLE_ONE ||
+                tok == token::DOUBLE_ZERO || tok == token::END_ARRAY || tok == token::END_OBJECT ||
+                tok == token::EQ || tok == token::EXPONENT || tok == token::FLOOR ||
+                tok == token::GT || tok == token::GTE || tok == token::ID ||
                 tok == token::INDEX_OF_BYTES || tok == token::INDEX_OF_CP ||
-                tok == token::INT_ZERO || tok == token::LITERAL || tok == token::LN ||
-                tok == token::LOG || tok == token::LOGTEN || tok == token::LONG_ZERO ||
-                tok == token::LT || tok == token::LTE || tok == token::LTRIM || tok == token::MOD ||
+                tok == token::INT_NEGATIVE_ONE || tok == token::INT_ONE || tok == token::INT_ZERO ||
+                tok == token::LITERAL || tok == token::LN || tok == token::LOG ||
+                tok == token::LOGTEN || tok == token::LONG_NEGATIVE_ONE || tok == token::LONG_ONE ||
+                tok == token::LONG_ZERO || tok == token::LT || tok == token::LTE ||
+                tok == token::LTRIM || tok == token::META || tok == token::MOD ||
                 tok == token::MULTIPLY || tok == token::NE || tok == token::NOT ||
-                tok == token::OR || tok == token::POW || tok == token::REGEX_FIND ||
-                tok == token::REGEX_FIND_ALL || tok == token::REGEX_MATCH ||
-                tok == token::REPLACE_ALL || tok == token::REPLACE_ONE || tok == token::ROUND ||
-                tok == token::RTRIM || tok == token::SPLIT || tok == token::SQRT ||
+                tok == token::OR || tok == token::POW || tok == token::RAND_VAL ||
+                tok == token::REGEX_FIND || tok == token::REGEX_FIND_ALL ||
+                tok == token::REGEX_MATCH || tok == token::REPLACE_ALL ||
+                tok == token::REPLACE_ONE || tok == token::ROUND || tok == token::RTRIM ||
+                tok == token::SPLIT || tok == token::SQRT ||
                 tok == token::STAGE_INHIBIT_OPTIMIZATION || tok == token::STAGE_LIMIT ||
                 tok == token::STAGE_PROJECT || tok == token::STAGE_SAMPLE ||
                 tok == token::STAGE_SKIP || tok == token::STAGE_UNION_WITH ||
                 tok == token::START_ARRAY || tok == token::START_OBJECT ||
                 tok == token::STR_CASE_CMP || tok == token::STR_LEN_BYTES ||
                 tok == token::STR_LEN_CP || tok == token::SUBSTR || tok == token::SUBSTR_BYTES ||
-                tok == token::SUBSTR_CP || tok == token::SUBTRACT || tok == token::TO_BOOL ||
-                tok == token::TO_DATE || tok == token::TO_DECIMAL || tok == token::TO_DOUBLE ||
-                tok == token::TO_INT || tok == token::TO_LONG || tok == token::TO_LOWER ||
-                tok == token::TO_OBJECT_ID || tok == token::TO_STRING || tok == token::TO_UPPER ||
-                tok == token::TRIM || tok == token::TRUNC || tok == token::TYPE ||
-                tok == token::START_PIPELINE || tok == token::START_MATCH);
+                tok == token::SUBSTR_CP || tok == token::SUBTRACT || tok == token::TEXT_SCORE ||
+                tok == token::TO_BOOL || tok == token::TO_DATE || tok == token::TO_DECIMAL ||
+                tok == token::TO_DOUBLE || tok == token::TO_INT || tok == token::TO_LONG ||
+                tok == token::TO_LOWER || tok == token::TO_OBJECT_ID || tok == token::TO_STRING ||
+                tok == token::TO_UPPER || tok == token::TRIM || tok == token::TRUNC ||
+                tok == token::TYPE || tok == token::START_PIPELINE || tok == token::START_MATCH ||
+                tok == token::START_SORT);
         }
 #endif
 #if 201103L <= YY_CPLUSPLUS
@@ -1395,12 +1989,12 @@ public:
 #if 201103L <= YY_CPLUSPLUS
         symbol_type(int tok, Decimal128 v, location_type l)
             : super_type(token_type(tok), std::move(v), std::move(l)) {
-            YY_ASSERT(tok == token::DECIMAL_NON_ZERO);
+            YY_ASSERT(tok == token::DECIMAL_OTHER);
         }
 #else
         symbol_type(int tok, const Decimal128& v, const location_type& l)
             : super_type(token_type(tok), v, l) {
-            YY_ASSERT(tok == token::DECIMAL_NON_ZERO);
+            YY_ASSERT(tok == token::DECIMAL_OTHER);
         }
 #endif
 #if 201103L <= YY_CPLUSPLUS
@@ -1472,34 +2066,34 @@ public:
 #if 201103L <= YY_CPLUSPLUS
         symbol_type(int tok, double v, location_type l)
             : super_type(token_type(tok), std::move(v), std::move(l)) {
-            YY_ASSERT(tok == token::DOUBLE_NON_ZERO);
+            YY_ASSERT(tok == token::DOUBLE_OTHER);
         }
 #else
         symbol_type(int tok, const double& v, const location_type& l)
             : super_type(token_type(tok), v, l) {
-            YY_ASSERT(tok == token::DOUBLE_NON_ZERO);
+            YY_ASSERT(tok == token::DOUBLE_OTHER);
         }
 #endif
 #if 201103L <= YY_CPLUSPLUS
         symbol_type(int tok, int v, location_type l)
             : super_type(token_type(tok), std::move(v), std::move(l)) {
-            YY_ASSERT(tok == token::INT_NON_ZERO);
+            YY_ASSERT(tok == token::INT_OTHER);
         }
 #else
         symbol_type(int tok, const int& v, const location_type& l)
             : super_type(token_type(tok), v, l) {
-            YY_ASSERT(tok == token::INT_NON_ZERO);
+            YY_ASSERT(tok == token::INT_OTHER);
         }
 #endif
 #if 201103L <= YY_CPLUSPLUS
         symbol_type(int tok, long long v, location_type l)
             : super_type(token_type(tok), std::move(v), std::move(l)) {
-            YY_ASSERT(tok == token::LONG_NON_ZERO);
+            YY_ASSERT(tok == token::LONG_OTHER);
         }
 #else
         symbol_type(int tok, const long long& v, const location_type& l)
             : super_type(token_type(tok), v, l) {
-            YY_ASSERT(tok == token::LONG_NON_ZERO);
+            YY_ASSERT(tok == token::LONG_OTHER);
         }
 #endif
 #if 201103L <= YY_CPLUSPLUS
@@ -1523,6 +2117,13 @@ public:
     PipelineParserGen(BSONLexer& lexer_yyarg, CNode* cst_yyarg);
     virtual ~PipelineParserGen();
 
+#if 201103L <= YY_CPLUSPLUS
+    /// Non copyable.
+    PipelineParserGen(const PipelineParserGen&) = delete;
+    /// Non copyable.
+    PipelineParserGen& operator=(const PipelineParserGen&) = delete;
+#endif
+
     /// Parse.  An alias for parse ().
     /// \returns  0 iff parsing succeeded.
     int operator()();
@@ -1553,6 +2154,10 @@ public:
     /// Report a syntax error.
     void error(const syntax_error& err);
 
+    /// The user-facing name of the symbol whose (internal) number is
+    /// YYSYMBOL.  No bounds checking.
+    static std::string symbol_name(symbol_kind_type yysymbol);
+
     // Implementation of make_symbol for each symbol type.
 #if 201103L <= YY_CPLUSPLUS
     static symbol_type make_END_OF_FILE(location_type l) {
@@ -1564,6 +2169,24 @@ public:
     }
 #endif
 #if 201103L <= YY_CPLUSPLUS
+    static symbol_type make_YYerror(location_type l) {
+        return symbol_type(token::YYerror, std::move(l));
+    }
+#else
+    static symbol_type make_YYerror(const location_type& l) {
+        return symbol_type(token::YYerror, l);
+    }
+#endif
+#if 201103L <= YY_CPLUSPLUS
+    static symbol_type make_YYUNDEF(location_type l) {
+        return symbol_type(token::YYUNDEF, std::move(l));
+    }
+#else
+    static symbol_type make_YYUNDEF(const location_type& l) {
+        return symbol_type(token::YYUNDEF, l);
+    }
+#endif
+#if 201103L <= YY_CPLUSPLUS
     static symbol_type make_ABS(location_type l) {
         return symbol_type(token::ABS, std::move(l));
     }
@@ -1825,6 +2448,24 @@ public:
     }
 #endif
 #if 201103L <= YY_CPLUSPLUS
+    static symbol_type make_DECIMAL_NEGATIVE_ONE(location_type l) {
+        return symbol_type(token::DECIMAL_NEGATIVE_ONE, std::move(l));
+    }
+#else
+    static symbol_type make_DECIMAL_NEGATIVE_ONE(const location_type& l) {
+        return symbol_type(token::DECIMAL_NEGATIVE_ONE, l);
+    }
+#endif
+#if 201103L <= YY_CPLUSPLUS
+    static symbol_type make_DECIMAL_ONE(location_type l) {
+        return symbol_type(token::DECIMAL_ONE, std::move(l));
+    }
+#else
+    static symbol_type make_DECIMAL_ONE(const location_type& l) {
+        return symbol_type(token::DECIMAL_ONE, l);
+    }
+#endif
+#if 201103L <= YY_CPLUSPLUS
     static symbol_type make_DECIMAL_ZERO(location_type l) {
         return symbol_type(token::DECIMAL_ZERO, std::move(l));
     }
@@ -1843,6 +2484,24 @@ public:
     }
 #endif
 #if 201103L <= YY_CPLUSPLUS
+    static symbol_type make_DOUBLE_NEGATIVE_ONE(location_type l) {
+        return symbol_type(token::DOUBLE_NEGATIVE_ONE, std::move(l));
+    }
+#else
+    static symbol_type make_DOUBLE_NEGATIVE_ONE(const location_type& l) {
+        return symbol_type(token::DOUBLE_NEGATIVE_ONE, l);
+    }
+#endif
+#if 201103L <= YY_CPLUSPLUS
+    static symbol_type make_DOUBLE_ONE(location_type l) {
+        return symbol_type(token::DOUBLE_ONE, std::move(l));
+    }
+#else
+    static symbol_type make_DOUBLE_ONE(const location_type& l) {
+        return symbol_type(token::DOUBLE_ONE, l);
+    }
+#endif
+#if 201103L <= YY_CPLUSPLUS
     static symbol_type make_DOUBLE_ZERO(location_type l) {
         return symbol_type(token::DOUBLE_ZERO, std::move(l));
     }
@@ -1942,6 +2601,24 @@ public:
     }
 #endif
 #if 201103L <= YY_CPLUSPLUS
+    static symbol_type make_INT_NEGATIVE_ONE(location_type l) {
+        return symbol_type(token::INT_NEGATIVE_ONE, std::move(l));
+    }
+#else
+    static symbol_type make_INT_NEGATIVE_ONE(const location_type& l) {
+        return symbol_type(token::INT_NEGATIVE_ONE, l);
+    }
+#endif
+#if 201103L <= YY_CPLUSPLUS
+    static symbol_type make_INT_ONE(location_type l) {
+        return symbol_type(token::INT_ONE, std::move(l));
+    }
+#else
+    static symbol_type make_INT_ONE(const location_type& l) {
+        return symbol_type(token::INT_ONE, l);
+    }
+#endif
+#if 201103L <= YY_CPLUSPLUS
     static symbol_type make_INT_ZERO(location_type l) {
         return symbol_type(token::INT_ZERO, std::move(l));
     }
@@ -1987,6 +2664,24 @@ public:
     }
 #endif
 #if 201103L <= YY_CPLUSPLUS
+    static symbol_type make_LONG_NEGATIVE_ONE(location_type l) {
+        return symbol_type(token::LONG_NEGATIVE_ONE, std::move(l));
+    }
+#else
+    static symbol_type make_LONG_NEGATIVE_ONE(const location_type& l) {
+        return symbol_type(token::LONG_NEGATIVE_ONE, l);
+    }
+#endif
+#if 201103L <= YY_CPLUSPLUS
+    static symbol_type make_LONG_ONE(location_type l) {
+        return symbol_type(token::LONG_ONE, std::move(l));
+    }
+#else
+    static symbol_type make_LONG_ONE(const location_type& l) {
+        return symbol_type(token::LONG_ONE, l);
+    }
+#endif
+#if 201103L <= YY_CPLUSPLUS
     static symbol_type make_LONG_ZERO(location_type l) {
         return symbol_type(token::LONG_ZERO, std::move(l));
     }
@@ -2023,6 +2718,15 @@ public:
     }
 #endif
 #if 201103L <= YY_CPLUSPLUS
+    static symbol_type make_META(location_type l) {
+        return symbol_type(token::META, std::move(l));
+    }
+#else
+    static symbol_type make_META(const location_type& l) {
+        return symbol_type(token::META, l);
+    }
+#endif
+#if 201103L <= YY_CPLUSPLUS
     static symbol_type make_MOD(location_type l) {
         return symbol_type(token::MOD, std::move(l));
     }
@@ -2077,6 +2781,15 @@ public:
     }
 #endif
 #if 201103L <= YY_CPLUSPLUS
+    static symbol_type make_RAND_VAL(location_type l) {
+        return symbol_type(token::RAND_VAL, std::move(l));
+    }
+#else
+    static symbol_type make_RAND_VAL(const location_type& l) {
+        return symbol_type(token::RAND_VAL, l);
+    }
+#endif
+#if 201103L <= YY_CPLUSPLUS
     static symbol_type make_REGEX_FIND(location_type l) {
         return symbol_type(token::REGEX_FIND, std::move(l));
     }
@@ -2293,6 +3006,15 @@ public:
     }
 #endif
 #if 201103L <= YY_CPLUSPLUS
+    static symbol_type make_TEXT_SCORE(location_type l) {
+        return symbol_type(token::TEXT_SCORE, std::move(l));
+    }
+#else
+    static symbol_type make_TEXT_SCORE(const location_type& l) {
+        return symbol_type(token::TEXT_SCORE, l);
+    }
+#endif
+#if 201103L <= YY_CPLUSPLUS
     static symbol_type make_TO_BOOL(location_type l) {
         return symbol_type(token::TO_BOOL, std::move(l));
     }
@@ -2518,39 +3240,39 @@ public:
     }
 #endif
 #if 201103L <= YY_CPLUSPLUS
-    static symbol_type make_INT_NON_ZERO(int v, location_type l) {
-        return symbol_type(token::INT_NON_ZERO, std::move(v), std::move(l));
+    static symbol_type make_INT_OTHER(int v, location_type l) {
+        return symbol_type(token::INT_OTHER, std::move(v), std::move(l));
     }
 #else
-    static symbol_type make_INT_NON_ZERO(const int& v, const location_type& l) {
-        return symbol_type(token::INT_NON_ZERO, v, l);
+    static symbol_type make_INT_OTHER(const int& v, const location_type& l) {
+        return symbol_type(token::INT_OTHER, v, l);
     }
 #endif
 #if 201103L <= YY_CPLUSPLUS
-    static symbol_type make_LONG_NON_ZERO(long long v, location_type l) {
-        return symbol_type(token::LONG_NON_ZERO, std::move(v), std::move(l));
+    static symbol_type make_LONG_OTHER(long long v, location_type l) {
+        return symbol_type(token::LONG_OTHER, std::move(v), std::move(l));
     }
 #else
-    static symbol_type make_LONG_NON_ZERO(const long long& v, const location_type& l) {
-        return symbol_type(token::LONG_NON_ZERO, v, l);
+    static symbol_type make_LONG_OTHER(const long long& v, const location_type& l) {
+        return symbol_type(token::LONG_OTHER, v, l);
     }
 #endif
 #if 201103L <= YY_CPLUSPLUS
-    static symbol_type make_DOUBLE_NON_ZERO(double v, location_type l) {
-        return symbol_type(token::DOUBLE_NON_ZERO, std::move(v), std::move(l));
+    static symbol_type make_DOUBLE_OTHER(double v, location_type l) {
+        return symbol_type(token::DOUBLE_OTHER, std::move(v), std::move(l));
     }
 #else
-    static symbol_type make_DOUBLE_NON_ZERO(const double& v, const location_type& l) {
-        return symbol_type(token::DOUBLE_NON_ZERO, v, l);
+    static symbol_type make_DOUBLE_OTHER(const double& v, const location_type& l) {
+        return symbol_type(token::DOUBLE_OTHER, v, l);
     }
 #endif
 #if 201103L <= YY_CPLUSPLUS
-    static symbol_type make_DECIMAL_NON_ZERO(Decimal128 v, location_type l) {
-        return symbol_type(token::DECIMAL_NON_ZERO, std::move(v), std::move(l));
+    static symbol_type make_DECIMAL_OTHER(Decimal128 v, location_type l) {
+        return symbol_type(token::DECIMAL_OTHER, std::move(v), std::move(l));
     }
 #else
-    static symbol_type make_DECIMAL_NON_ZERO(const Decimal128& v, const location_type& l) {
-        return symbol_type(token::DECIMAL_NON_ZERO, v, l);
+    static symbol_type make_DECIMAL_OTHER(const Decimal128& v, const location_type& l) {
+        return symbol_type(token::DECIMAL_OTHER, v, l);
     }
 #endif
 #if 201103L <= YY_CPLUSPLUS
@@ -2625,21 +3347,60 @@ public:
         return symbol_type(token::START_MATCH, l);
     }
 #endif
+#if 201103L <= YY_CPLUSPLUS
+    static symbol_type make_START_SORT(location_type l) {
+        return symbol_type(token::START_SORT, std::move(l));
+    }
+#else
+    static symbol_type make_START_SORT(const location_type& l) {
+        return symbol_type(token::START_SORT, l);
+    }
+#endif
+
+
+    class context {
+    public:
+        context(const PipelineParserGen& yyparser, const symbol_type& yyla);
+        const symbol_type& lookahead() const {
+            return yyla_;
+        }
+        symbol_kind_type token() const {
+            return yyla_.kind();
+        }
+        const location_type& location() const {
+            return yyla_.location;
+        }
 
+        /// Put in YYARG at most YYARGN of the expected tokens, and return the
+        /// number of tokens stored in YYARG.  If YYARG is null, return the
+        /// number of expected tokens (guaranteed to be less than YYNTOKENS).
+        int expected_tokens(symbol_kind_type yyarg[], int yyargn) const;
+
+    private:
+        const PipelineParserGen& yyparser_;
+        const symbol_type& yyla_;
+    };
 
 private:
-    /// This class is not copyable.
+#if YY_CPLUSPLUS < 201103L
+    /// Non copyable.
     PipelineParserGen(const PipelineParserGen&);
+    /// Non copyable.
     PipelineParserGen& operator=(const PipelineParserGen&);
+#endif
+
 
     /// Stored state numbers (used for stacks).
     typedef short state_type;
 
-    /// Generate an error message.
-    /// \param yystate   the state where the error occurred.
-    /// \param yyla      the lookahead token.
-    virtual std::string yysyntax_error_(state_type yystate, const symbol_type& yyla) const;
+    /// The arguments of the error message.
+    int yy_syntax_error_arguments_(const context& yyctx,
+                                   symbol_kind_type yyarg[],
+                                   int yyargn) const;
 
+    /// Generate an error message.
+    /// \param yyctx     the context in which the error occurred.
+    virtual std::string yysyntax_error_(const context& yyctx) const;
     /// Compute post-reduction state.
     /// \param yystate   the current state
     /// \param yysym     the nonterminal to push on the stack
@@ -2656,10 +3417,17 @@ private:
     static const short yypact_ninf_;
     static const signed char yytable_ninf_;
 
-    /// Convert a scanner token number \a t to a symbol number.
-    /// In theory \a t should be a token_type, but character literals
+    /// Convert a scanner token kind \a t to a symbol kind.
+    /// In theory \a t should be a token_kind_type, but character literals
     /// are valid, yet not members of the token_type enum.
-    static token_number_type yytranslate_(int t);
+    static symbol_kind_type yytranslate_(int t);
+
+    /// Convert the symbol name \a n to a form suitable for a diagnostic.
+    static std::string yytnamerr_(const char* yystr);
+
+    /// For a symbol, its name in clear.
+    static const char* const yytname_[];
+
 
     // Tables.
     // YYPACT[STATE-NUM] -- Index in YYTABLE of the portion describing
@@ -2695,26 +3463,20 @@ private:
     static const signed char yyr2_[];
 
 
-    /// Convert the symbol name \a n to a form suitable for a diagnostic.
-    static std::string yytnamerr_(const char* n);
-
-
-    /// For a symbol, its name in clear.
-    static const char* const yytname_[];
 #if YYDEBUG
     // YYRLINE[YYN] -- Source line where rule number YYN was defined.
     static const short yyrline_[];
     /// Report on the debug stream that the rule \a r is going to be reduced.
-    virtual void yy_reduce_print_(int r);
+    virtual void yy_reduce_print_(int r) const;
     /// Print the state stack on the debug stream.
-    virtual void yystack_print_();
+    virtual void yy_stack_print_() const;
 
     /// Debugging level.
     int yydebug_;
     /// Debug stream.
     std::ostream* yycdebug_;
 
-    /// \brief Display a symbol type, value and location.
+    /// \brief Display a symbol kind, value and location.
     /// \param yyo    The output stream.
     /// \param yysym  The symbol.
     template <typename Base>
@@ -2734,7 +3496,7 @@ private:
         /// Default constructor.
         by_state() YY_NOEXCEPT;
 
-        /// The symbol type as needed by the constructor.
+        /// The symbol kind as needed by the constructor.
         typedef state_type kind_type;
 
         /// Constructor.
@@ -2746,12 +3508,12 @@ private:
         /// Record that this symbol is empty.
         void clear() YY_NOEXCEPT;
 
-        /// Steal the symbol type from \a that.
+        /// Steal the symbol kind from \a that.
         void move(by_state& that);
 
-        /// The (internal) type number (corresponding to \a state).
-        /// \a empty_symbol when empty.
-        symbol_number_type type_get() const YY_NOEXCEPT;
+        /// The symbol kind (corresponding to \a state).
+        /// \a symbol_kind::S_YYEMPTY when empty.
+        symbol_kind_type kind() const YY_NOEXCEPT;
 
         /// The state number used to denote an empty symbol.
         /// We use the initial state, as it does not have a value.
@@ -2788,13 +3550,20 @@ private:
     class stack {
     public:
         // Hide our reversed order.
-        typedef typename S::reverse_iterator iterator;
-        typedef typename S::const_reverse_iterator const_iterator;
+        typedef typename S::iterator iterator;
+        typedef typename S::const_iterator const_iterator;
         typedef typename S::size_type size_type;
         typedef typename std::ptrdiff_t index_type;
 
         stack(size_type n = 200) : seq_(n) {}
 
+#if 201103L <= YY_CPLUSPLUS
+        /// Non copyable.
+        stack(const stack&) = delete;
+        /// Non copyable.
+        stack& operator=(const stack&) = delete;
+#endif
+
         /// Random access.
         ///
         /// Index 0 returns the topmost element.
@@ -2833,18 +3602,14 @@ private:
             return index_type(seq_.size());
         }
 
-        std::ptrdiff_t ssize() const YY_NOEXCEPT {
-            return std::ptrdiff_t(size());
-        }
-
         /// Iterator on top of the stack (going downwards).
         const_iterator begin() const YY_NOEXCEPT {
-            return seq_.rbegin();
+            return seq_.begin();
         }
 
         /// Bottom of the stack.
         const_iterator end() const YY_NOEXCEPT {
-            return seq_.rend();
+            return seq_.end();
         }
 
         /// Present a slice of the top of a stack.
@@ -2862,8 +3627,12 @@ private:
         };
 
     private:
+#if YY_CPLUSPLUS < 201103L
+        /// Non copyable.
         stack(const stack&);
+        /// Non copyable.
         stack& operator=(const stack&);
+#endif
         /// The wrapped container.
         S seq_;
     };
@@ -2893,17 +3662,11 @@ private:
     /// Pop \a n symbols from the stack.
     void yypop_(int n = 1);
 
-    /// Some specific tokens.
-    static const token_number_type yy_error_token_ = 1;
-    static const token_number_type yy_undef_token_ = 2;
-
     /// Constants.
     enum {
-        yyeof_ = 0,
-        yylast_ = 951,    ///< Last index in yytable_.
-        yynnts_ = 142,    ///< Number of nonterminal symbols.
-        yyfinal_ = 8,     ///< Termination state number.
-        yyntokens_ = 121  ///< Number of tokens.
+        yylast_ = 1306,  ///< Last index in yytable_.
+        yynnts_ = 148,   ///< Number of nonterminal symbols.
+        yyfinal_ = 11    ///< Termination state number.
     };
 
 
@@ -2912,475 +3675,244 @@ private:
     CNode* cst;
 };
 
-inline PipelineParserGen::token_number_type PipelineParserGen::yytranslate_(int t) {
-    return static_cast<token_number_type>(t);
+inline PipelineParserGen::symbol_kind_type PipelineParserGen::yytranslate_(int t) {
+    return static_cast<symbol_kind_type>(t);
 }
 
 // basic_symbol.
-#if 201103L <= YY_CPLUSPLUS
-template <typename Base>
-PipelineParserGen::basic_symbol<Base>::basic_symbol(basic_symbol&& that)
-    : Base(std::move(that)), value(), location(std::move(that.location)) {
-    switch (this->type_get()) {
-        case 99:  // "BinData"
-            value.move<BSONBinData>(std::move(that.value));
-            break;
-
-        case 106:  // "Code"
-            value.move<BSONCode>(std::move(that.value));
-            break;
-
-        case 108:  // "CodeWScope"
-            value.move<BSONCodeWScope>(std::move(that.value));
-            break;
-
-        case 105:  // "dbPointer"
-            value.move<BSONDBRef>(std::move(that.value));
-            break;
-
-        case 104:  // "regex"
-            value.move<BSONRegEx>(std::move(that.value));
-            break;
-
-        case 107:  // "Symbol"
-            value.move<BSONSymbol>(std::move(that.value));
-            break;
-
-        case 135:  // dbPointer
-        case 136:  // javascript
-        case 137:  // symbol
-        case 138:  // javascriptWScope
-        case 139:  // int
-        case 140:  // timestamp
-        case 141:  // long
-        case 142:  // double
-        case 143:  // decimal
-        case 144:  // minKey
-        case 145:  // maxKey
-        case 146:  // value
-        case 147:  // string
-        case 148:  // fieldPath
-        case 149:  // binary
-        case 150:  // undefined
-        case 151:  // objectId
-        case 152:  // bool
-        case 153:  // date
-        case 154:  // null
-        case 155:  // regex
-        case 156:  // simpleValue
-        case 157:  // compoundValue
-        case 158:  // valueArray
-        case 159:  // valueObject
-        case 160:  // valueFields
-        case 161:  // variable
-        case 162:  // pipeline
-        case 163:  // stageList
-        case 164:  // stage
-        case 165:  // inhibitOptimization
-        case 166:  // unionWith
-        case 167:  // skip
-        case 168:  // limit
-        case 169:  // project
-        case 170:  // sample
-        case 171:  // projectFields
-        case 172:  // projection
-        case 173:  // num
-        case 174:  // expression
-        case 175:  // compoundExpression
-        case 176:  // exprFixedTwoArg
-        case 177:  // expressionArray
-        case 178:  // expressionObject
-        case 179:  // expressionFields
-        case 180:  // maths
-        case 181:  // add
-        case 182:  // atan2
-        case 183:  // boolExps
-        case 184:  // and
-        case 185:  // or
-        case 186:  // not
-        case 187:  // literalEscapes
-        case 188:  // const
-        case 189:  // literal
-        case 190:  // stringExps
-        case 191:  // concat
-        case 192:  // dateFromString
-        case 193:  // dateToString
-        case 194:  // indexOfBytes
-        case 195:  // indexOfCP
-        case 196:  // ltrim
-        case 197:  // regexFind
-        case 198:  // regexFindAll
-        case 199:  // regexMatch
-        case 200:  // regexArgs
-        case 201:  // replaceOne
-        case 202:  // replaceAll
-        case 203:  // rtrim
-        case 204:  // split
-        case 205:  // strLenBytes
-        case 206:  // strLenCP
-        case 207:  // strcasecmp
-        case 208:  // substr
-        case 209:  // substrBytes
-        case 210:  // substrCP
-        case 211:  // toLower
-        case 212:  // toUpper
-        case 213:  // trim
-        case 214:  // compExprs
-        case 215:  // cmp
-        case 216:  // eq
-        case 217:  // gt
-        case 218:  // gte
-        case 219:  // lt
-        case 220:  // lte
-        case 221:  // ne
-        case 222:  // typeExpression
-        case 223:  // convert
-        case 224:  // toBool
-        case 225:  // toDate
-        case 226:  // toDecimal
-        case 227:  // toDouble
-        case 228:  // toInt
-        case 229:  // toLong
-        case 230:  // toObjectId
-        case 231:  // toString
-        case 232:  // type
-        case 233:  // abs
-        case 234:  // ceil
-        case 235:  // divide
-        case 236:  // exponent
-        case 237:  // floor
-        case 238:  // ln
-        case 239:  // log
-        case 240:  // logten
-        case 241:  // mod
-        case 242:  // multiply
-        case 243:  // pow
-        case 244:  // round
-        case 245:  // sqrt
-        case 246:  // subtract
-        case 247:  // trunc
-        case 257:  // matchExpression
-        case 258:  // filterFields
-        case 259:  // filterVal
-            value.move<CNode>(std::move(that.value));
-            break;
-
-        case 122:  // projectionFieldname
-        case 123:  // expressionFieldname
-        case 124:  // stageAsUserFieldname
-        case 125:  // filterFieldname
-        case 126:  // argAsUserFieldname
-        case 127:  // aggExprAsUserFieldname
-        case 128:  // invariableUserFieldname
-        case 129:  // idAsUserFieldname
-        case 130:  // valueFieldname
-            value.move<CNode::Fieldname>(std::move(that.value));
-            break;
-
-        case 102:  // "Date"
-            value.move<Date_t>(std::move(that.value));
-            break;
-
-        case 112:  // "non-zero decimal"
-            value.move<Decimal128>(std::move(that.value));
-            break;
-
-        case 101:  // "ObjectID"
-            value.move<OID>(std::move(that.value));
-            break;
-
-        case 113:  // "Timestamp"
-            value.move<Timestamp>(std::move(that.value));
-            break;
-
-        case 115:  // "maxKey"
-            value.move<UserMaxKey>(std::move(that.value));
-            break;
-
-        case 114:  // "minKey"
-            value.move<UserMinKey>(std::move(that.value));
-            break;
-
-        case 103:  // "null"
-            value.move<UserNull>(std::move(that.value));
-            break;
-
-        case 100:  // "undefined"
-            value.move<UserUndefined>(std::move(that.value));
-            break;
-
-        case 111:  // "non-zero double"
-            value.move<double>(std::move(that.value));
-            break;
-
-        case 109:  // "non-zero integer"
-            value.move<int>(std::move(that.value));
-            break;
-
-        case 110:  // "non-zero long"
-            value.move<long long>(std::move(that.value));
-            break;
-
-        case 131:  // projectField
-        case 132:  // expressionField
-        case 133:  // valueField
-        case 134:  // filterField
-        case 248:  // onErrorArg
-        case 249:  // onNullArg
-        case 250:  // formatArg
-        case 251:  // timezoneArg
-        case 252:  // charsArg
-        case 253:  // optionsArg
-            value.move<std::pair<CNode::Fieldname, CNode>>(std::move(that.value));
-            break;
-
-        case 97:   // "fieldname"
-        case 98:   // "string"
-        case 116:  // "$-prefixed string"
-        case 117:  // "$$-prefixed string"
-        case 118:  // "$-prefixed fieldname"
-            value.move<std::string>(std::move(that.value));
-            break;
-
-        case 254:  // expressions
-        case 255:  // values
-        case 256:  // exprZeroToTwo
-            value.move<std::vector<CNode>>(std::move(that.value));
-            break;
-
-        default:
-            break;
-    }
-}
-#endif
-
 template <typename Base>
 PipelineParserGen::basic_symbol<Base>::basic_symbol(const basic_symbol& that)
     : Base(that), value(), location(that.location) {
-    switch (this->type_get()) {
-        case 99:  // "BinData"
+    switch (this->kind()) {
+        case symbol_kind::S_BINARY:  // "BinData"
             value.copy<BSONBinData>(YY_MOVE(that.value));
             break;
 
-        case 106:  // "Code"
+        case symbol_kind::S_JAVASCRIPT:  // "Code"
             value.copy<BSONCode>(YY_MOVE(that.value));
             break;
 
-        case 108:  // "CodeWScope"
+        case symbol_kind::S_JAVASCRIPT_W_SCOPE:  // "CodeWScope"
             value.copy<BSONCodeWScope>(YY_MOVE(that.value));
             break;
 
-        case 105:  // "dbPointer"
+        case symbol_kind::S_DB_POINTER:  // "dbPointer"
             value.copy<BSONDBRef>(YY_MOVE(that.value));
             break;
 
-        case 104:  // "regex"
+        case symbol_kind::S_REGEX:  // "regex"
             value.copy<BSONRegEx>(YY_MOVE(that.value));
             break;
 
-        case 107:  // "Symbol"
+        case symbol_kind::S_SYMBOL:  // "Symbol"
             value.copy<BSONSymbol>(YY_MOVE(that.value));
             break;
 
-        case 135:  // dbPointer
-        case 136:  // javascript
-        case 137:  // symbol
-        case 138:  // javascriptWScope
-        case 139:  // int
-        case 140:  // timestamp
-        case 141:  // long
-        case 142:  // double
-        case 143:  // decimal
-        case 144:  // minKey
-        case 145:  // maxKey
-        case 146:  // value
-        case 147:  // string
-        case 148:  // fieldPath
-        case 149:  // binary
-        case 150:  // undefined
-        case 151:  // objectId
-        case 152:  // bool
-        case 153:  // date
-        case 154:  // null
-        case 155:  // regex
-        case 156:  // simpleValue
-        case 157:  // compoundValue
-        case 158:  // valueArray
-        case 159:  // valueObject
-        case 160:  // valueFields
-        case 161:  // variable
-        case 162:  // pipeline
-        case 163:  // stageList
-        case 164:  // stage
-        case 165:  // inhibitOptimization
-        case 166:  // unionWith
-        case 167:  // skip
-        case 168:  // limit
-        case 169:  // project
-        case 170:  // sample
-        case 171:  // projectFields
-        case 172:  // projection
-        case 173:  // num
-        case 174:  // expression
-        case 175:  // compoundExpression
-        case 176:  // exprFixedTwoArg
-        case 177:  // expressionArray
-        case 178:  // expressionObject
-        case 179:  // expressionFields
-        case 180:  // maths
-        case 181:  // add
-        case 182:  // atan2
-        case 183:  // boolExps
-        case 184:  // and
-        case 185:  // or
-        case 186:  // not
-        case 187:  // literalEscapes
-        case 188:  // const
-        case 189:  // literal
-        case 190:  // stringExps
-        case 191:  // concat
-        case 192:  // dateFromString
-        case 193:  // dateToString
-        case 194:  // indexOfBytes
-        case 195:  // indexOfCP
-        case 196:  // ltrim
-        case 197:  // regexFind
-        case 198:  // regexFindAll
-        case 199:  // regexMatch
-        case 200:  // regexArgs
-        case 201:  // replaceOne
-        case 202:  // replaceAll
-        case 203:  // rtrim
-        case 204:  // split
-        case 205:  // strLenBytes
-        case 206:  // strLenCP
-        case 207:  // strcasecmp
-        case 208:  // substr
-        case 209:  // substrBytes
-        case 210:  // substrCP
-        case 211:  // toLower
-        case 212:  // toUpper
-        case 213:  // trim
-        case 214:  // compExprs
-        case 215:  // cmp
-        case 216:  // eq
-        case 217:  // gt
-        case 218:  // gte
-        case 219:  // lt
-        case 220:  // lte
-        case 221:  // ne
-        case 222:  // typeExpression
-        case 223:  // convert
-        case 224:  // toBool
-        case 225:  // toDate
-        case 226:  // toDecimal
-        case 227:  // toDouble
-        case 228:  // toInt
-        case 229:  // toLong
-        case 230:  // toObjectId
-        case 231:  // toString
-        case 232:  // type
-        case 233:  // abs
-        case 234:  // ceil
-        case 235:  // divide
-        case 236:  // exponent
-        case 237:  // floor
-        case 238:  // ln
-        case 239:  // log
-        case 240:  // logten
-        case 241:  // mod
-        case 242:  // multiply
-        case 243:  // pow
-        case 244:  // round
-        case 245:  // sqrt
-        case 246:  // subtract
-        case 247:  // trunc
-        case 257:  // matchExpression
-        case 258:  // filterFields
-        case 259:  // filterVal
+        case symbol_kind::S_dbPointer:            // dbPointer
+        case symbol_kind::S_javascript:           // javascript
+        case symbol_kind::S_symbol:               // symbol
+        case symbol_kind::S_javascriptWScope:     // javascriptWScope
+        case symbol_kind::S_int:                  // int
+        case symbol_kind::S_timestamp:            // timestamp
+        case symbol_kind::S_long:                 // long
+        case symbol_kind::S_double:               // double
+        case symbol_kind::S_decimal:              // decimal
+        case symbol_kind::S_minKey:               // minKey
+        case symbol_kind::S_maxKey:               // maxKey
+        case symbol_kind::S_value:                // value
+        case symbol_kind::S_string:               // string
+        case symbol_kind::S_fieldPath:            // fieldPath
+        case symbol_kind::S_binary:               // binary
+        case symbol_kind::S_undefined:            // undefined
+        case symbol_kind::S_objectId:             // objectId
+        case symbol_kind::S_bool:                 // bool
+        case symbol_kind::S_date:                 // date
+        case symbol_kind::S_null:                 // null
+        case symbol_kind::S_regex:                // regex
+        case symbol_kind::S_simpleValue:          // simpleValue
+        case symbol_kind::S_compoundValue:        // compoundValue
+        case symbol_kind::S_valueArray:           // valueArray
+        case symbol_kind::S_valueObject:          // valueObject
+        case symbol_kind::S_valueFields:          // valueFields
+        case symbol_kind::S_variable:             // variable
+        case symbol_kind::S_pipeline:             // pipeline
+        case symbol_kind::S_stageList:            // stageList
+        case symbol_kind::S_stage:                // stage
+        case symbol_kind::S_inhibitOptimization:  // inhibitOptimization
+        case symbol_kind::S_unionWith:            // unionWith
+        case symbol_kind::S_skip:                 // skip
+        case symbol_kind::S_limit:                // limit
+        case symbol_kind::S_project:              // project
+        case symbol_kind::S_sample:               // sample
+        case symbol_kind::S_projectFields:        // projectFields
+        case symbol_kind::S_projection:           // projection
+        case symbol_kind::S_num:                  // num
+        case symbol_kind::S_expression:           // expression
+        case symbol_kind::S_compoundExpression:   // compoundExpression
+        case symbol_kind::S_exprFixedTwoArg:      // exprFixedTwoArg
+        case symbol_kind::S_expressionArray:      // expressionArray
+        case symbol_kind::S_expressionObject:     // expressionObject
+        case symbol_kind::S_expressionFields:     // expressionFields
+        case symbol_kind::S_maths:                // maths
+        case symbol_kind::S_add:                  // add
+        case symbol_kind::S_atan2:                // atan2
+        case symbol_kind::S_boolExps:             // boolExps
+        case symbol_kind::S_and:                  // and
+        case symbol_kind::S_or:                   // or
+        case symbol_kind::S_not:                  // not
+        case symbol_kind::S_literalEscapes:       // literalEscapes
+        case symbol_kind::S_const:                // const
+        case symbol_kind::S_literal:              // literal
+        case symbol_kind::S_stringExps:           // stringExps
+        case symbol_kind::S_concat:               // concat
+        case symbol_kind::S_dateFromString:       // dateFromString
+        case symbol_kind::S_dateToString:         // dateToString
+        case symbol_kind::S_indexOfBytes:         // indexOfBytes
+        case symbol_kind::S_indexOfCP:            // indexOfCP
+        case symbol_kind::S_ltrim:                // ltrim
+        case symbol_kind::S_regexFind:            // regexFind
+        case symbol_kind::S_regexFindAll:         // regexFindAll
+        case symbol_kind::S_regexMatch:           // regexMatch
+        case symbol_kind::S_regexArgs:            // regexArgs
+        case symbol_kind::S_replaceOne:           // replaceOne
+        case symbol_kind::S_replaceAll:           // replaceAll
+        case symbol_kind::S_rtrim:                // rtrim
+        case symbol_kind::S_split:                // split
+        case symbol_kind::S_strLenBytes:          // strLenBytes
+        case symbol_kind::S_strLenCP:             // strLenCP
+        case symbol_kind::S_strcasecmp:           // strcasecmp
+        case symbol_kind::S_substr:               // substr
+        case symbol_kind::S_substrBytes:          // substrBytes
+        case symbol_kind::S_substrCP:             // substrCP
+        case symbol_kind::S_toLower:              // toLower
+        case symbol_kind::S_toUpper:              // toUpper
+        case symbol_kind::S_trim:                 // trim
+        case symbol_kind::S_compExprs:            // compExprs
+        case symbol_kind::S_cmp:                  // cmp
+        case symbol_kind::S_eq:                   // eq
+        case symbol_kind::S_gt:                   // gt
+        case symbol_kind::S_gte:                  // gte
+        case symbol_kind::S_lt:                   // lt
+        case symbol_kind::S_lte:                  // lte
+        case symbol_kind::S_ne:                   // ne
+        case symbol_kind::S_typeExpression:       // typeExpression
+        case symbol_kind::S_convert:              // convert
+        case symbol_kind::S_toBool:               // toBool
+        case symbol_kind::S_toDate:               // toDate
+        case symbol_kind::S_toDecimal:            // toDecimal
+        case symbol_kind::S_toDouble:             // toDouble
+        case symbol_kind::S_toInt:                // toInt
+        case symbol_kind::S_toLong:               // toLong
+        case symbol_kind::S_toObjectId:           // toObjectId
+        case symbol_kind::S_toString:             // toString
+        case symbol_kind::S_type:                 // type
+        case symbol_kind::S_abs:                  // abs
+        case symbol_kind::S_ceil:                 // ceil
+        case symbol_kind::S_divide:               // divide
+        case symbol_kind::S_exponent:             // exponent
+        case symbol_kind::S_floor:                // floor
+        case symbol_kind::S_ln:                   // ln
+        case symbol_kind::S_log:                  // log
+        case symbol_kind::S_logten:               // logten
+        case symbol_kind::S_mod:                  // mod
+        case symbol_kind::S_multiply:             // multiply
+        case symbol_kind::S_pow:                  // pow
+        case symbol_kind::S_round:                // round
+        case symbol_kind::S_sqrt:                 // sqrt
+        case symbol_kind::S_subtract:             // subtract
+        case symbol_kind::S_trunc:                // trunc
+        case symbol_kind::S_matchExpression:      // matchExpression
+        case symbol_kind::S_filterFields:         // filterFields
+        case symbol_kind::S_filterVal:            // filterVal
+        case symbol_kind::S_sortSpecs:            // sortSpecs
+        case symbol_kind::S_specList:             // specList
+        case symbol_kind::S_metaSort:             // metaSort
+        case symbol_kind::S_oneOrNegOne:          // oneOrNegOne
+        case symbol_kind::S_metaSortKeyword:      // metaSortKeyword
             value.copy<CNode>(YY_MOVE(that.value));
             break;
 
-        case 122:  // projectionFieldname
-        case 123:  // expressionFieldname
-        case 124:  // stageAsUserFieldname
-        case 125:  // filterFieldname
-        case 126:  // argAsUserFieldname
-        case 127:  // aggExprAsUserFieldname
-        case 128:  // invariableUserFieldname
-        case 129:  // idAsUserFieldname
-        case 130:  // valueFieldname
+        case symbol_kind::S_projectionFieldname:      // projectionFieldname
+        case symbol_kind::S_expressionFieldname:      // expressionFieldname
+        case symbol_kind::S_stageAsUserFieldname:     // stageAsUserFieldname
+        case symbol_kind::S_filterFieldname:          // filterFieldname
+        case symbol_kind::S_argAsUserFieldname:       // argAsUserFieldname
+        case symbol_kind::S_aggExprAsUserFieldname:   // aggExprAsUserFieldname
+        case symbol_kind::S_invariableUserFieldname:  // invariableUserFieldname
+        case symbol_kind::S_idAsUserFieldname:        // idAsUserFieldname
+        case symbol_kind::S_valueFieldname:           // valueFieldname
             value.copy<CNode::Fieldname>(YY_MOVE(that.value));
             break;
 
-        case 102:  // "Date"
+        case symbol_kind::S_DATE_LITERAL:  // "Date"
             value.copy<Date_t>(YY_MOVE(that.value));
             break;
 
-        case 112:  // "non-zero decimal"
+        case symbol_kind::S_DECIMAL_OTHER:  // "arbitrary decimal"
             value.copy<Decimal128>(YY_MOVE(that.value));
             break;
 
-        case 101:  // "ObjectID"
+        case symbol_kind::S_OBJECT_ID:  // "ObjectID"
             value.copy<OID>(YY_MOVE(that.value));
             break;
 
-        case 113:  // "Timestamp"
+        case symbol_kind::S_TIMESTAMP:  // "Timestamp"
             value.copy<Timestamp>(YY_MOVE(that.value));
             break;
 
-        case 115:  // "maxKey"
+        case symbol_kind::S_MAX_KEY:  // "maxKey"
             value.copy<UserMaxKey>(YY_MOVE(that.value));
             break;
 
-        case 114:  // "minKey"
+        case symbol_kind::S_MIN_KEY:  // "minKey"
             value.copy<UserMinKey>(YY_MOVE(that.value));
             break;
 
-        case 103:  // "null"
+        case symbol_kind::S_JSNULL:  // "null"
             value.copy<UserNull>(YY_MOVE(that.value));
             break;
 
-        case 100:  // "undefined"
+        case symbol_kind::S_UNDEFINED:  // "undefined"
             value.copy<UserUndefined>(YY_MOVE(that.value));
             break;
 
-        case 111:  // "non-zero double"
+        case symbol_kind::S_DOUBLE_OTHER:  // "arbitrary double"
             value.copy<double>(YY_MOVE(that.value));
             break;
 
-        case 109:  // "non-zero integer"
+        case symbol_kind::S_INT_OTHER:  // "arbitrary integer"
             value.copy<int>(YY_MOVE(that.value));
             break;
 
-        case 110:  // "non-zero long"
+        case symbol_kind::S_LONG_OTHER:  // "arbitrary long"
             value.copy<long long>(YY_MOVE(that.value));
             break;
 
-        case 131:  // projectField
-        case 132:  // expressionField
-        case 133:  // valueField
-        case 134:  // filterField
-        case 248:  // onErrorArg
-        case 249:  // onNullArg
-        case 250:  // formatArg
-        case 251:  // timezoneArg
-        case 252:  // charsArg
-        case 253:  // optionsArg
+        case symbol_kind::S_projectField:     // projectField
+        case symbol_kind::S_expressionField:  // expressionField
+        case symbol_kind::S_valueField:       // valueField
+        case symbol_kind::S_filterField:      // filterField
+        case symbol_kind::S_onErrorArg:       // onErrorArg
+        case symbol_kind::S_onNullArg:        // onNullArg
+        case symbol_kind::S_formatArg:        // formatArg
+        case symbol_kind::S_timezoneArg:      // timezoneArg
+        case symbol_kind::S_charsArg:         // charsArg
+        case symbol_kind::S_optionsArg:       // optionsArg
+        case symbol_kind::S_sortSpec:         // sortSpec
             value.copy<std::pair<CNode::Fieldname, CNode>>(YY_MOVE(that.value));
             break;
 
-        case 97:   // "fieldname"
-        case 98:   // "string"
-        case 116:  // "$-prefixed string"
-        case 117:  // "$$-prefixed string"
-        case 118:  // "$-prefixed fieldname"
+        case symbol_kind::S_FIELDNAME:              // "fieldname"
+        case symbol_kind::S_STRING:                 // "string"
+        case symbol_kind::S_DOLLAR_STRING:          // "$-prefixed string"
+        case symbol_kind::S_DOLLAR_DOLLAR_STRING:   // "$$-prefixed string"
+        case symbol_kind::S_DOLLAR_PREF_FIELDNAME:  // "$-prefixed fieldname"
             value.copy<std::string>(YY_MOVE(that.value));
             break;
 
-        case 254:  // expressions
-        case 255:  // values
-        case 256:  // exprZeroToTwo
+        case symbol_kind::S_expressions:    // expressions
+        case symbol_kind::S_values:         // values
+        case symbol_kind::S_exprZeroToTwo:  // exprZeroToTwo
             value.copy<std::vector<CNode>>(YY_MOVE(that.value));
             break;
 
@@ -3391,237 +3923,249 @@ PipelineParserGen::basic_symbol<Base>::basic_symbol(const basic_symbol& that)
 
 
 template <typename Base>
+PipelineParserGen::symbol_kind_type PipelineParserGen::basic_symbol<Base>::type_get() const
+    YY_NOEXCEPT {
+    return this->kind();
+}
+
+template <typename Base>
 bool PipelineParserGen::basic_symbol<Base>::empty() const YY_NOEXCEPT {
-    return Base::type_get() == empty_symbol;
+    return this->kind() == symbol_kind::S_YYEMPTY;
 }
 
 template <typename Base>
 void PipelineParserGen::basic_symbol<Base>::move(basic_symbol& s) {
     super_type::move(s);
-    switch (this->type_get()) {
-        case 99:  // "BinData"
+    switch (this->kind()) {
+        case symbol_kind::S_BINARY:  // "BinData"
             value.move<BSONBinData>(YY_MOVE(s.value));
             break;
 
-        case 106:  // "Code"
+        case symbol_kind::S_JAVASCRIPT:  // "Code"
             value.move<BSONCode>(YY_MOVE(s.value));
             break;
 
-        case 108:  // "CodeWScope"
+        case symbol_kind::S_JAVASCRIPT_W_SCOPE:  // "CodeWScope"
             value.move<BSONCodeWScope>(YY_MOVE(s.value));
             break;
 
-        case 105:  // "dbPointer"
+        case symbol_kind::S_DB_POINTER:  // "dbPointer"
             value.move<BSONDBRef>(YY_MOVE(s.value));
             break;
 
-        case 104:  // "regex"
+        case symbol_kind::S_REGEX:  // "regex"
             value.move<BSONRegEx>(YY_MOVE(s.value));
             break;
 
-        case 107:  // "Symbol"
+        case symbol_kind::S_SYMBOL:  // "Symbol"
             value.move<BSONSymbol>(YY_MOVE(s.value));
             break;
 
-        case 135:  // dbPointer
-        case 136:  // javascript
-        case 137:  // symbol
-        case 138:  // javascriptWScope
-        case 139:  // int
-        case 140:  // timestamp
-        case 141:  // long
-        case 142:  // double
-        case 143:  // decimal
-        case 144:  // minKey
-        case 145:  // maxKey
-        case 146:  // value
-        case 147:  // string
-        case 148:  // fieldPath
-        case 149:  // binary
-        case 150:  // undefined
-        case 151:  // objectId
-        case 152:  // bool
-        case 153:  // date
-        case 154:  // null
-        case 155:  // regex
-        case 156:  // simpleValue
-        case 157:  // compoundValue
-        case 158:  // valueArray
-        case 159:  // valueObject
-        case 160:  // valueFields
-        case 161:  // variable
-        case 162:  // pipeline
-        case 163:  // stageList
-        case 164:  // stage
-        case 165:  // inhibitOptimization
-        case 166:  // unionWith
-        case 167:  // skip
-        case 168:  // limit
-        case 169:  // project
-        case 170:  // sample
-        case 171:  // projectFields
-        case 172:  // projection
-        case 173:  // num
-        case 174:  // expression
-        case 175:  // compoundExpression
-        case 176:  // exprFixedTwoArg
-        case 177:  // expressionArray
-        case 178:  // expressionObject
-        case 179:  // expressionFields
-        case 180:  // maths
-        case 181:  // add
-        case 182:  // atan2
-        case 183:  // boolExps
-        case 184:  // and
-        case 185:  // or
-        case 186:  // not
-        case 187:  // literalEscapes
-        case 188:  // const
-        case 189:  // literal
-        case 190:  // stringExps
-        case 191:  // concat
-        case 192:  // dateFromString
-        case 193:  // dateToString
-        case 194:  // indexOfBytes
-        case 195:  // indexOfCP
-        case 196:  // ltrim
-        case 197:  // regexFind
-        case 198:  // regexFindAll
-        case 199:  // regexMatch
-        case 200:  // regexArgs
-        case 201:  // replaceOne
-        case 202:  // replaceAll
-        case 203:  // rtrim
-        case 204:  // split
-        case 205:  // strLenBytes
-        case 206:  // strLenCP
-        case 207:  // strcasecmp
-        case 208:  // substr
-        case 209:  // substrBytes
-        case 210:  // substrCP
-        case 211:  // toLower
-        case 212:  // toUpper
-        case 213:  // trim
-        case 214:  // compExprs
-        case 215:  // cmp
-        case 216:  // eq
-        case 217:  // gt
-        case 218:  // gte
-        case 219:  // lt
-        case 220:  // lte
-        case 221:  // ne
-        case 222:  // typeExpression
-        case 223:  // convert
-        case 224:  // toBool
-        case 225:  // toDate
-        case 226:  // toDecimal
-        case 227:  // toDouble
-        case 228:  // toInt
-        case 229:  // toLong
-        case 230:  // toObjectId
-        case 231:  // toString
-        case 232:  // type
-        case 233:  // abs
-        case 234:  // ceil
-        case 235:  // divide
-        case 236:  // exponent
-        case 237:  // floor
-        case 238:  // ln
-        case 239:  // log
-        case 240:  // logten
-        case 241:  // mod
-        case 242:  // multiply
-        case 243:  // pow
-        case 244:  // round
-        case 245:  // sqrt
-        case 246:  // subtract
-        case 247:  // trunc
-        case 257:  // matchExpression
-        case 258:  // filterFields
-        case 259:  // filterVal
+        case symbol_kind::S_dbPointer:            // dbPointer
+        case symbol_kind::S_javascript:           // javascript
+        case symbol_kind::S_symbol:               // symbol
+        case symbol_kind::S_javascriptWScope:     // javascriptWScope
+        case symbol_kind::S_int:                  // int
+        case symbol_kind::S_timestamp:            // timestamp
+        case symbol_kind::S_long:                 // long
+        case symbol_kind::S_double:               // double
+        case symbol_kind::S_decimal:              // decimal
+        case symbol_kind::S_minKey:               // minKey
+        case symbol_kind::S_maxKey:               // maxKey
+        case symbol_kind::S_value:                // value
+        case symbol_kind::S_string:               // string
+        case symbol_kind::S_fieldPath:            // fieldPath
+        case symbol_kind::S_binary:               // binary
+        case symbol_kind::S_undefined:            // undefined
+        case symbol_kind::S_objectId:             // objectId
+        case symbol_kind::S_bool:                 // bool
+        case symbol_kind::S_date:                 // date
+        case symbol_kind::S_null:                 // null
+        case symbol_kind::S_regex:                // regex
+        case symbol_kind::S_simpleValue:          // simpleValue
+        case symbol_kind::S_compoundValue:        // compoundValue
+        case symbol_kind::S_valueArray:           // valueArray
+        case symbol_kind::S_valueObject:          // valueObject
+        case symbol_kind::S_valueFields:          // valueFields
+        case symbol_kind::S_variable:             // variable
+        case symbol_kind::S_pipeline:             // pipeline
+        case symbol_kind::S_stageList:            // stageList
+        case symbol_kind::S_stage:                // stage
+        case symbol_kind::S_inhibitOptimization:  // inhibitOptimization
+        case symbol_kind::S_unionWith:            // unionWith
+        case symbol_kind::S_skip:                 // skip
+        case symbol_kind::S_limit:                // limit
+        case symbol_kind::S_project:              // project
+        case symbol_kind::S_sample:               // sample
+        case symbol_kind::S_projectFields:        // projectFields
+        case symbol_kind::S_projection:           // projection
+        case symbol_kind::S_num:                  // num
+        case symbol_kind::S_expression:           // expression
+        case symbol_kind::S_compoundExpression:   // compoundExpression
+        case symbol_kind::S_exprFixedTwoArg:      // exprFixedTwoArg
+        case symbol_kind::S_expressionArray:      // expressionArray
+        case symbol_kind::S_expressionObject:     // expressionObject
+        case symbol_kind::S_expressionFields:     // expressionFields
+        case symbol_kind::S_maths:                // maths
+        case symbol_kind::S_add:                  // add
+        case symbol_kind::S_atan2:                // atan2
+        case symbol_kind::S_boolExps:             // boolExps
+        case symbol_kind::S_and:                  // and
+        case symbol_kind::S_or:                   // or
+        case symbol_kind::S_not:                  // not
+        case symbol_kind::S_literalEscapes:       // literalEscapes
+        case symbol_kind::S_const:                // const
+        case symbol_kind::S_literal:              // literal
+        case symbol_kind::S_stringExps:           // stringExps
+        case symbol_kind::S_concat:               // concat
+        case symbol_kind::S_dateFromString:       // dateFromString
+        case symbol_kind::S_dateToString:         // dateToString
+        case symbol_kind::S_indexOfBytes:         // indexOfBytes
+        case symbol_kind::S_indexOfCP:            // indexOfCP
+        case symbol_kind::S_ltrim:                // ltrim
+        case symbol_kind::S_regexFind:            // regexFind
+        case symbol_kind::S_regexFindAll:         // regexFindAll
+        case symbol_kind::S_regexMatch:           // regexMatch
+        case symbol_kind::S_regexArgs:            // regexArgs
+        case symbol_kind::S_replaceOne:           // replaceOne
+        case symbol_kind::S_replaceAll:           // replaceAll
+        case symbol_kind::S_rtrim:                // rtrim
+        case symbol_kind::S_split:                // split
+        case symbol_kind::S_strLenBytes:          // strLenBytes
+        case symbol_kind::S_strLenCP:             // strLenCP
+        case symbol_kind::S_strcasecmp:           // strcasecmp
+        case symbol_kind::S_substr:               // substr
+        case symbol_kind::S_substrBytes:          // substrBytes
+        case symbol_kind::S_substrCP:             // substrCP
+        case symbol_kind::S_toLower:              // toLower
+        case symbol_kind::S_toUpper:              // toUpper
+        case symbol_kind::S_trim:                 // trim
+        case symbol_kind::S_compExprs:            // compExprs
+        case symbol_kind::S_cmp:                  // cmp
+        case symbol_kind::S_eq:                   // eq
+        case symbol_kind::S_gt:                   // gt
+        case symbol_kind::S_gte:                  // gte
+        case symbol_kind::S_lt:                   // lt
+        case symbol_kind::S_lte:                  // lte
+        case symbol_kind::S_ne:                   // ne
+        case symbol_kind::S_typeExpression:       // typeExpression
+        case symbol_kind::S_convert:              // convert
+        case symbol_kind::S_toBool:               // toBool
+        case symbol_kind::S_toDate:               // toDate
+        case symbol_kind::S_toDecimal:            // toDecimal
+        case symbol_kind::S_toDouble:             // toDouble
+        case symbol_kind::S_toInt:                // toInt
+        case symbol_kind::S_toLong:               // toLong
+        case symbol_kind::S_toObjectId:           // toObjectId
+        case symbol_kind::S_toString:             // toString
+        case symbol_kind::S_type:                 // type
+        case symbol_kind::S_abs:                  // abs
+        case symbol_kind::S_ceil:                 // ceil
+        case symbol_kind::S_divide:               // divide
+        case symbol_kind::S_exponent:             // exponent
+        case symbol_kind::S_floor:                // floor
+        case symbol_kind::S_ln:                   // ln
+        case symbol_kind::S_log:                  // log
+        case symbol_kind::S_logten:               // logten
+        case symbol_kind::S_mod:                  // mod
+        case symbol_kind::S_multiply:             // multiply
+        case symbol_kind::S_pow:                  // pow
+        case symbol_kind::S_round:                // round
+        case symbol_kind::S_sqrt:                 // sqrt
+        case symbol_kind::S_subtract:             // subtract
+        case symbol_kind::S_trunc:                // trunc
+        case symbol_kind::S_matchExpression:      // matchExpression
+        case symbol_kind::S_filterFields:         // filterFields
+        case symbol_kind::S_filterVal:            // filterVal
+        case symbol_kind::S_sortSpecs:            // sortSpecs
+        case symbol_kind::S_specList:             // specList
+        case symbol_kind::S_metaSort:             // metaSort
+        case symbol_kind::S_oneOrNegOne:          // oneOrNegOne
+        case symbol_kind::S_metaSortKeyword:      // metaSortKeyword
             value.move<CNode>(YY_MOVE(s.value));
             break;
 
-        case 122:  // projectionFieldname
-        case 123:  // expressionFieldname
-        case 124:  // stageAsUserFieldname
-        case 125:  // filterFieldname
-        case 126:  // argAsUserFieldname
-        case 127:  // aggExprAsUserFieldname
-        case 128:  // invariableUserFieldname
-        case 129:  // idAsUserFieldname
-        case 130:  // valueFieldname
+        case symbol_kind::S_projectionFieldname:      // projectionFieldname
+        case symbol_kind::S_expressionFieldname:      // expressionFieldname
+        case symbol_kind::S_stageAsUserFieldname:     // stageAsUserFieldname
+        case symbol_kind::S_filterFieldname:          // filterFieldname
+        case symbol_kind::S_argAsUserFieldname:       // argAsUserFieldname
+        case symbol_kind::S_aggExprAsUserFieldname:   // aggExprAsUserFieldname
+        case symbol_kind::S_invariableUserFieldname:  // invariableUserFieldname
+        case symbol_kind::S_idAsUserFieldname:        // idAsUserFieldname
+        case symbol_kind::S_valueFieldname:           // valueFieldname
             value.move<CNode::Fieldname>(YY_MOVE(s.value));
             break;
 
-        case 102:  // "Date"
+        case symbol_kind::S_DATE_LITERAL:  // "Date"
             value.move<Date_t>(YY_MOVE(s.value));
             break;
 
-        case 112:  // "non-zero decimal"
+        case symbol_kind::S_DECIMAL_OTHER:  // "arbitrary decimal"
             value.move<Decimal128>(YY_MOVE(s.value));
             break;
 
-        case 101:  // "ObjectID"
+        case symbol_kind::S_OBJECT_ID:  // "ObjectID"
             value.move<OID>(YY_MOVE(s.value));
             break;
 
-        case 113:  // "Timestamp"
+        case symbol_kind::S_TIMESTAMP:  // "Timestamp"
             value.move<Timestamp>(YY_MOVE(s.value));
             break;
 
-        case 115:  // "maxKey"
+        case symbol_kind::S_MAX_KEY:  // "maxKey"
             value.move<UserMaxKey>(YY_MOVE(s.value));
             break;
 
-        case 114:  // "minKey"
+        case symbol_kind::S_MIN_KEY:  // "minKey"
             value.move<UserMinKey>(YY_MOVE(s.value));
             break;
 
-        case 103:  // "null"
+        case symbol_kind::S_JSNULL:  // "null"
             value.move<UserNull>(YY_MOVE(s.value));
             break;
 
-        case 100:  // "undefined"
+        case symbol_kind::S_UNDEFINED:  // "undefined"
             value.move<UserUndefined>(YY_MOVE(s.value));
             break;
 
-        case 111:  // "non-zero double"
+        case symbol_kind::S_DOUBLE_OTHER:  // "arbitrary double"
             value.move<double>(YY_MOVE(s.value));
             break;
 
-        case 109:  // "non-zero integer"
+        case symbol_kind::S_INT_OTHER:  // "arbitrary integer"
             value.move<int>(YY_MOVE(s.value));
             break;
 
-        case 110:  // "non-zero long"
+        case symbol_kind::S_LONG_OTHER:  // "arbitrary long"
             value.move<long long>(YY_MOVE(s.value));
             break;
 
-        case 131:  // projectField
-        case 132:  // expressionField
-        case 133:  // valueField
-        case 134:  // filterField
-        case 248:  // onErrorArg
-        case 249:  // onNullArg
-        case 250:  // formatArg
-        case 251:  // timezoneArg
-        case 252:  // charsArg
-        case 253:  // optionsArg
+        case symbol_kind::S_projectField:     // projectField
+        case symbol_kind::S_expressionField:  // expressionField
+        case symbol_kind::S_valueField:       // valueField
+        case symbol_kind::S_filterField:      // filterField
+        case symbol_kind::S_onErrorArg:       // onErrorArg
+        case symbol_kind::S_onNullArg:        // onNullArg
+        case symbol_kind::S_formatArg:        // formatArg
+        case symbol_kind::S_timezoneArg:      // timezoneArg
+        case symbol_kind::S_charsArg:         // charsArg
+        case symbol_kind::S_optionsArg:       // optionsArg
+        case symbol_kind::S_sortSpec:         // sortSpec
             value.move<std::pair<CNode::Fieldname, CNode>>(YY_MOVE(s.value));
             break;
 
-        case 97:   // "fieldname"
-        case 98:   // "string"
-        case 116:  // "$-prefixed string"
-        case 117:  // "$$-prefixed string"
-        case 118:  // "$-prefixed fieldname"
+        case symbol_kind::S_FIELDNAME:              // "fieldname"
+        case symbol_kind::S_STRING:                 // "string"
+        case symbol_kind::S_DOLLAR_STRING:          // "$-prefixed string"
+        case symbol_kind::S_DOLLAR_DOLLAR_STRING:   // "$$-prefixed string"
+        case symbol_kind::S_DOLLAR_PREF_FIELDNAME:  // "$-prefixed fieldname"
             value.move<std::string>(YY_MOVE(s.value));
             break;
 
-        case 254:  // expressions
-        case 255:  // values
-        case 256:  // exprZeroToTwo
+        case symbol_kind::S_expressions:    // expressions
+        case symbol_kind::S_values:         // values
+        case symbol_kind::S_exprZeroToTwo:  // exprZeroToTwo
             value.move<std::vector<CNode>>(YY_MOVE(s.value));
             break;
 
@@ -3632,35 +4176,40 @@ void PipelineParserGen::basic_symbol<Base>::move(basic_symbol& s) {
     location = YY_MOVE(s.location);
 }
 
-// by_type.
-inline PipelineParserGen::by_type::by_type() : type(empty_symbol) {}
+// by_kind.
+inline PipelineParserGen::by_kind::by_kind() : kind_(symbol_kind::S_YYEMPTY) {}
 
 #if 201103L <= YY_CPLUSPLUS
-inline PipelineParserGen::by_type::by_type(by_type&& that) : type(that.type) {
+inline PipelineParserGen::by_kind::by_kind(by_kind&& that) : kind_(that.kind_) {
     that.clear();
 }
 #endif
 
-inline PipelineParserGen::by_type::by_type(const by_type& that) : type(that.type) {}
+inline PipelineParserGen::by_kind::by_kind(const by_kind& that) : kind_(that.kind_) {}
 
-inline PipelineParserGen::by_type::by_type(token_type t) : type(yytranslate_(t)) {}
+inline PipelineParserGen::by_kind::by_kind(token_kind_type t) : kind_(yytranslate_(t)) {}
 
-inline void PipelineParserGen::by_type::clear() {
-    type = empty_symbol;
+inline void PipelineParserGen::by_kind::clear() {
+    kind_ = symbol_kind::S_YYEMPTY;
 }
 
-inline void PipelineParserGen::by_type::move(by_type& that) {
-    type = that.type;
+inline void PipelineParserGen::by_kind::move(by_kind& that) {
+    kind_ = that.kind_;
     that.clear();
 }
 
-inline int PipelineParserGen::by_type::type_get() const YY_NOEXCEPT {
-    return type;
+inline PipelineParserGen::symbol_kind_type PipelineParserGen::by_kind::kind() const YY_NOEXCEPT {
+    return kind_;
+}
+
+inline PipelineParserGen::symbol_kind_type PipelineParserGen::by_kind::type_get() const
+    YY_NOEXCEPT {
+    return this->kind();
 }
 
-#line 58 "src/mongo/db/cst/pipeline_grammar.yy"
+#line 58 "pipeline_grammar.yy"
 }  // namespace mongo
-#line 4606 "src/mongo/db/cst/pipeline_parser_gen.hpp"
+#line 5223 "pipeline_parser_gen.hpp"
 
 
-#endif  // !YY_YY_SRC_MONGO_DB_CST_PIPELINE_PARSER_GEN_HPP_INCLUDED
+#endif  // !YY_YY_PIPELINE_PARSER_GEN_HPP_INCLUDED
diff --git a/src/mongo/db/pipeline/expression.h b/src/mongo/db/pipeline/expression.h
index fc6f16c0eb8..2dfa80f74f3 100644
--- a/src/mongo/db/pipeline/expression.h
+++ b/src/mongo/db/pipeline/expression.h
@@ -1755,6 +1755,8 @@ private:
 
 class ExpressionMeta final : public Expression {
 public:
+    ExpressionMeta(ExpressionContext* const expCtx, DocumentMetadataFields::MetaType metaType);
+
     Value serialize(bool explain) const final;
     Value evaluate(const Document& root, Variables* variables) const final;
 
@@ -1774,8 +1776,6 @@ protected:
     void _doAddDependencies(DepsTracker* deps) const final;
 
 private:
-    ExpressionMeta(ExpressionContext* const expCtx, DocumentMetadataFields::MetaType metaType);
-
     DocumentMetadataFields::MetaType _metaType;
 };
 
diff --git a/src/mongo/db/query/sort_pattern.h b/src/mongo/db/query/sort_pattern.h
index 6c7103a5dfd..0be6e347ac9 100644
--- a/src/mongo/db/query/sort_pattern.h
+++ b/src/mongo/db/query/sort_pattern.h
@@ -54,6 +54,9 @@ public:
 
     SortPattern(const BSONObj&, const boost::intrusive_ptr<ExpressionContext>&);
 
+    SortPattern(std::vector<SortPatternPart> patterns, std::set<std::string> paths)
+        : _sortPattern(std::move(patterns)), _paths(std::move(paths)) {}
+
     /**
      * Write out a Document whose contents are the sort key pattern.
      */
author	Ted Tuckman <ted.tuckman@mongodb.com>	2020-08-31 13:14:03 -0400
committer	Evergreen Agent <no-reply@evergreen.mongodb.com>	2020-09-03 18:08:41 +0000
commit	8e3271aaf22106853bf36429cfcee39ed6055f35 (patch)
tree	a2c1648af5ba4e905ca9b8d50f8a1055fd9576a5
parent	c4aa65bbd510369498ef7202596775c7824c87ce (diff)
download	mongo-8e3271aaf22106853bf36429cfcee39ed6055f35.tar.gz