Minor grammar and clean-compile tidying

Make grammar productions all <90 characters (they mostly were anyway, and some long names just weren't needed)

I changed some that ended in _-list_ to just end in _s_ (for plural), but left some like _expression-list_ because they were already short and read better with a dash (I think _expression-list_ reads better than _expressions_, YMMV)

Also added `-Wno-error=dangling-reference` to avoid a false positive in GCC 13; see #818 (comment)

.github/workflows/build-cppfront.yaml

@@ -42,7 +42,7 @@ jobs:
     runs-on: ${{ matrix.runs-on }}
     env:
       CXX: ${{ matrix.compiler }}
-      CXXFLAGS: -std=${{ matrix.cxx-std }} -Wall -Wextra -Wold-style-cast -Wunused-parameter -Wpedantic -Werror -pthread
+      CXXFLAGS: -std=${{ matrix.cxx-std }} -Wall -Wextra -Wold-style-cast -Wunused-parameter -Wno-error=dangling-reference -Wpedantic -Werror -pthread
     steps:
     - uses: actions/checkout@v3
     - name: Install compiler

source/lex.h

@@ -872,8 +872,11 @@ auto lex_line(
     };
 
     //G universal-character-name:
-    //G     '\u' hexadecimal-digit hexadecimal-digit hexadecimal-digit hexadecimal-digit
-    //G     '\U' hexadecimal-digit hexadecimal-digit hexadecimal-digit hexadecimal-digit hexadecimal-digit hexadecimal-digit hexadecimal-digit hexadecimal-digit
+    //G     '\u' hex-quad
+    //G     '\U' hex-quad hex-quad
+    //G
+    //G hex-quad:
+    //G     hexadecimal-digit hexadecimal-digit hexadecimal-digit hexadecimal-digit
     //G
     auto peek_is_universal_character_name = [&](colno_t offset)
     {
@@ -1506,7 +1509,7 @@ auto lex_line(
                 //G     decimal-literal ''' digit [uU][lL][lL]
                 //G
                 //G floating-point-literal:
-                //G     digit { ' | digit }* . digit ({ ' | digit }*)? ([eE][-+]?digit { ' | digit }*) [fFlL]
+                //G     digit { ''' | digit }* . digit ({ ''' | digit }*)? ([eE][-+]?digit { ' | digit }*) [fFlL]
                 //G
                 //G TODO full grammar & refactor to utility functions with their
                 //G      own unit test rather than inline everything here

source/parse.h

@@ -6334,13 +6334,13 @@ class parser
     //G     is-as-expression as-type-cast
     //GTODO     type-id is-type-constraint
     //G
-    //G is-type-constraint
+    //G is-type-constraint:
     //G     'is' type-id
     //G
-    //G is-value-constraint
+    //G is-value-constraint:
     //G     'is' expression
     //G
-    //G as-type-cast
+    //G as-type-cast:
     //G     'as' type-id
     //G
     auto is_as_expression()
@@ -6424,10 +6424,10 @@ class parser
     //G     ...
     //G
     //G template-id:
-    //G     identifier '<' template-argument-list? '>'
+    //G     identifier '<' template-arguments? '>'
     //G
-    //G template-argument-list:
-    //G     template-argument-list ',' template-argument
+    //G template-arguments:
+    //G     template-arguments ',' template-argument
     //G
     //G template-argument:
     //G     # note: < > << >> are not allowed in expressions until new ( is opened
@@ -6456,7 +6456,7 @@ class parser
         one_past_identifier_end_pos.colno += curr().length();
         next();
 
-        //  Handle the template-argument-list if there is one
+        //  Handle the template-arguments if there is one
         if (
             curr().type() == lexeme::Less
             && curr().position() == one_past_identifier_end_pos
@@ -7281,7 +7281,7 @@ class parser
     //G     declaration
     //G     expression-statement
     //G
-    //G contract-statement
+    //G contract-statement:
     //G     contract ';'
     //
     //GTODO     try-block
@@ -7656,7 +7656,7 @@ class parser
     }
 
 
-    //G parameter-declaration-list
+    //G parameter-declaration-list:
     //G     '(' parameter-declaration-seq? ')'
     //G
     //G parameter-declaration-seq:
@@ -8004,22 +8004,22 @@ class parser
 
 
     //G unnamed-declaration:
-    //G     ':' meta-functions-list? template-parameter-declaration-list? function-type requires-clause? '=' statement
-    //G     ':' meta-functions-list? template-parameter-declaration-list? function-type statement
-    //G     ':' meta-functions-list? template-parameter-declaration-list? type-id? requires-clause? '=' statement
-    //G     ':' meta-functions-list? template-parameter-declaration-list? type-id
-    //G     ':' meta-functions-list? template-parameter-declaration-list? 'final'? 'type' requires-clause? '=' statement
+    //G     ':' meta-functions? template-parameters? function-type requires-clause? '=' statement
+    //G     ':' meta-functions? template-parameters? function-type statement
+    //G     ':' meta-functions? template-parameters? type-id? requires-clause? '=' statement
+    //G     ':' meta-functions? template-parameters? type-id
+    //G     ':' meta-functions? template-parameters? 'final'? 'type' requires-clause? '=' statement
     //G     ':' 'namespace' '=' statement
     //G
-    //G meta-functions-list:
+    //G meta-functions:
     //G     '@' id-expression
-    //G     meta-functions-list '@' id-expression
+    //G     meta-functions '@' id-expression
     //G
     //G requires-clause:
     //G      # note: for aliases, == is not allowed in expressions until new ( is opened
     //G      'requires' logical-or-expression
     //G
-    //G template-parameter-declaration-list
+    //G template-parameters:
     //G     '<' parameter-declaration-seq '>'
     //G
     auto unnamed_declaration(
@@ -8527,9 +8527,9 @@ class parser
 
 
     //G alias:
-    //G     ':' template-parameter-declaration-list? 'type' requires-clause? '==' type-id ';'
+    //G     ':' template-parameters? 'type' requires-clause? '==' type-id ';'
     //G     ':' 'namespace' '==' id-expression ';'
-    //G     ':' template-parameter-declaration-list? type-id? requires-clause? '==' expression ';'
+    //G     ':' template-parameters? type-id? requires-clause? '==' expression ';'
     //G
     //GT     ':' function-type '==' expression ';'
     //GT        # See commit 63efa6ed21c4d4f4f136a7a73e9f6b2c110c81d7 comment