Refactor error generation for pattern synonyms

The result of a series of patches on type-error messages for
pattern synonyms had become a bit baroque. This tidies it up
a bit.  Still not fantastic, but better.

2 files changed, 8 insertions, 10 deletions

diff --git a/testsuite/tests/patsyn/should_fail/T11039.stderr b/testsuite/tests/patsyn/should_fail/T11039.stderr
index eea6257f58..9b749d1758 100644
--- a/testsuite/tests/patsyn/should_fail/T11039.stderr
+++ b/testsuite/tests/patsyn/should_fail/T11039.stderr
@@ -2,7 +2,7 @@
 T11039.hs:8:15: error:
     • Couldn't match type ‘f’ with ‘A’
       ‘f’ is a rigid type variable bound by
-        the type signature of pattern synonym ‘Q’ at T11039.hs:7:14
+        the signature for pattern synonym ‘Q’ at T11039.hs:7:14
       Expected type: f a
         Actual type: A a
     • In the pattern: A a
diff --git a/testsuite/tests/patsyn/should_fail/T11667.stderr b/testsuite/tests/patsyn/should_fail/T11667.stderr
index 6befe1386c..95b6e929ad 100644
--- a/testsuite/tests/patsyn/should_fail/T11667.stderr
+++ b/testsuite/tests/patsyn/should_fail/T11667.stderr
@@ -2,11 +2,11 @@
 T11667.hs:12:22: error:
     • Could not deduce (Num a) arising from the literal ‘42’
       from the context: Eq a
-        bound by the type signature of pattern synonym ‘Pat1’
+        bound by the signature for pattern synonym ‘Pat1’
         at T11667.hs:12:9-12
       Possible fix:
-        add (Num a) to the context of
-          the type signature of pattern synonym ‘Pat1’
+        add (Num a) to the "required" context of
+          the signature for pattern synonym ‘Pat1’
     • In the pattern: 42
       In the pattern: Just 42
       In the declaration for pattern synonym ‘Pat1’
@@ -16,7 +16,7 @@ T11667.hs:18:28: error:
         arising from the "provided" constraints claimed by
           the signature of ‘Pat2’
       ‘b’ is a rigid type variable bound by
-        the type signature of pattern synonym ‘Pat2’ at T11667.hs:17:17
+        the signature for pattern synonym ‘Pat2’ at T11667.hs:17:17
     • In the declaration for pattern synonym ‘Pat2’
     • Relevant bindings include y :: b (bound at T11667.hs:18:21)
 
@@ -32,12 +32,10 @@ T11667.hs:24:24: error:
 T11667.hs:31:16: error:
     • Could not deduce (Num a) arising from a use of ‘MkS’
       from the context: (Eq a, Show a)
-        bound by the type signature for bidirectional pattern synonym ‘Pat4’
-                 when used in an expression context:
-                   (Eq a, Show a) => S a
+        bound by the signature for pattern synonym ‘Pat4’
         at T11667.hs:31:1-21
       Possible fix:
-        add (Num a) to the context of
-          the type signature of pattern synonym ‘Pat4’
+        add (Num a) to the "required" context of
+          the signature for pattern synonym ‘Pat4’
     • In the expression: MkS 42
       In an equation for ‘$bPat4’: $bPat4 = MkS 42