Remove assignment to __class__ in Word, remove internal _WordRegex class

3 files changed, 15 insertions, 14 deletions

diff --git a/pyparsing/core.py b/pyparsing/core.py
index e34cfee..11f7368 100644
--- a/pyparsing/core.py
+++ b/pyparsing/core.py
@@ -2868,7 +2868,7 @@ class Word(Token):
                 self.re = None
             else:
                 self.re_match = self.re.match
-                self.__class__ = _WordRegex
+                self.parseImpl = self.parseImpl_regex
 
     def _generateDefaultName(self) -> str:
         def charsAsStr(s):
@@ -2929,9 +2929,7 @@ class Word(Token):
 
         return loc, instring[start:loc]
 
-
-class _WordRegex(Word):
-    def parseImpl(self, instring, loc, doActions=True):
+    def parseImpl_regex(self, instring, loc, doActions=True):
         result = self.re_match(instring, loc)
         if not result:
             raise ParseException(instring, loc, self.errmsg, self)
@@ -2940,7 +2938,7 @@ class _WordRegex(Word):
         return loc, result.group()
 
 
-class Char(_WordRegex):
+class Char(Word):
     """A short-cut class for defining :class:`Word` ``(characters, exact=1)``,
     when defining a match of any single character in a string of
     characters.
@@ -2958,13 +2956,8 @@ class Char(_WordRegex):
         asKeyword = asKeyword or as_keyword
         excludeChars = excludeChars or exclude_chars
         super().__init__(
-            charset, exact=1, asKeyword=asKeyword, excludeChars=excludeChars
+            charset, exact=1, as_keyword=asKeyword, exclude_chars=excludeChars
         )
-        self.reString = f"[{_collapse_string_to_ranges(self.initChars)}]"
-        if asKeyword:
-            self.reString = rf"\b{self.reString}\b"
-        self.re = re.compile(self.reString)
-        self.re_match = self.re.match
 
 
 class Regex(Token):
diff --git a/pyparsing/exceptions.py b/pyparsing/exceptions.py
index ed88ad2..b0694c3 100644
--- a/pyparsing/exceptions.py
+++ b/pyparsing/exceptions.py
@@ -80,7 +80,7 @@ class ParseBaseException(Exception):
 
                 f_self = frm.f_locals.get("self", None)
                 if isinstance(f_self, ParserElement):
-                    if frm.f_code.co_name not in ("parseImpl", "_parseNoCache"):
+                    if not frm.f_code.co_name.startswith(("parseImpl", "_parseNoCache")):
                         continue
                     if id(f_self) in seen:
                         continue
diff --git a/tests/test_unit.py b/tests/test_unit.py
index 370c2cf..b7a23d0 100644
--- a/tests/test_unit.py
+++ b/tests/test_unit.py
@@ -4860,6 +4860,10 @@ class Test02_WithoutPackrat(ppt.TestParseResultsAsserts, TestCase):
             result2, expected2, msg="issue with Char asKeyword=True parsing 2 chars"
         )
 
+    def testCharRe(self):
+        expr = pp.Char("ABCDEFG")
+        self.assertEqual("[A-G]", expr.reString)
+
     def testCharsNotIn(self):
         """test CharsNotIn initialized with various arguments"""
 
@@ -9229,7 +9233,7 @@ class Test02_WithoutPackrat(ppt.TestParseResultsAsserts, TestCase):
 
             expected = [
                 self_testcase_name,
-                "pyparsing.core._WordRegex - integer",
+                "pyparsing.core.Word - integer",
                 "tests.test_unit.Modifier",
                 "pyparsing.results.ParseResults",
             ]
@@ -9274,8 +9278,12 @@ class Test02_WithoutPackrat(ppt.TestParseResultsAsserts, TestCase):
             depth_0_explain_str = pe.explain(depth=0)
             depth_1_explain_str = pe.explain(depth=1)
             print(depth_none_explain_str)
+            print()
+            print(depth_0_explain_str)
+            print()
+            print(depth_1_explain_str)
 
-            expr_name = "pyparsing.core._WordRegex - W:(0-9)"
+            expr_name = "pyparsing.core.Word - W:(0-9)"
             for expected_function in [self_testcase_name, expr_name]:
                 self.assertTrue(
                     expected_function in depth_none_explain_str,