Changeset 55ba259e

Timestamp:

Jun 26, 2024, 10:25:26 AM (3 days ago)

Author:

Peter A. Buhr <pabuhr@…>

Branches:

master

Children:

01afd8d

Parents:

d5efcb7

Message:

clarify for-control for enumerations

File:

• src/Parser/parser.yy (modified) (3 diffs)

src/Parser/parser.yy

@@ -10 +10 @@
 // Created On       : Sat Sep  1 20:22:55 2001
 // Last Modified By : Peter A. Buhr
-// Last Modified On : Tue Jun 25 18:44:14 2024
-// Update Count     : 6692
+// Last Modified On : Wed Jun 26 09:37:28 2024
+// Update Count     : 6700
 //
 
@@ -1607 +1607 @@
         | comma_expression ';' enum_key                                         // CFA, enum type
                 {
-                        $$ = enumRangeCtrl( $1, OperKinds::LThan, new ExpressionNode( new ast::TypeExpr( yylloc, $3->buildType() ) ) );
+                        $$ = enumRangeCtrl( $1, OperKinds::LEThan, new ExpressionNode( new ast::TypeExpr( yylloc, $3->buildType() ) ) );
                 }
         | comma_expression ';' downupdowneq enum_key            // CFA, enum type, reverse direction
                 {
-                        if ( $3 == OperKinds::LEThan || $3 == OperKinds::GEThan ) {
-                                SemanticError( yylloc, "illegal syntax, all enumeration ranges are equal (all values). Remove \"=~\"." ); $$ = nullptr;
-                        }
+                        if ( $3 == OperKinds::GThan ) {
+                                SemanticError( yylloc, "all enumeration ranges are equal (all values). Add an equal, e.g., ~=, -~=." ); $$ = nullptr;
+                                $3 = OperKinds::GEThan;
+                        } // if
                         $$ = enumRangeCtrl( $1, $3, new ExpressionNode( new ast::TypeExpr( yylloc, $4->buildType() ) ) );
                 }
@@ -1627 +1628 @@
         ;
 
+// This rule exists to handle the ambiguity with unary operator '~'. The rule is the same as updowneq minus the '~'.
+// Specifically, "for ( ~5 )" means the complement of 5, not loop 0..4. Hence, in this case "for ( ~= 5 )", i.e., 0..5,
+// it is not possible to just remove the '='. The entire '~=' must be removed.
 downupdowneq:
         ErangeDown