Remove case functions implementation

We're removing this feature as per RFC 51.

Closes ponylang#2540.

pony.g

@@ -208,8 +208,8 @@ nextatom
   | LPAREN_NEW rawseq tuple? ')'
   | LSQUARE_NEW ('as' type ':')? rawseq? ']'
   | 'object' ('\\' ID (',' ID)* '\\')? cap? ('is' type)? members 'end'
-  | '{' ('\\' ID (',' ID)* '\\')? cap? ID? typeparams? ('(' | LPAREN_NEW) params? ')' lambdacaptures? (':' type)? '?'? '=>' rawseq '}' cap?
-  | '@{' ('\\' ID (',' ID)* '\\')? cap? ID? typeparams? ('(' | LPAREN_NEW) params? ')' lambdacaptures? (':' type)? '?'? '=>' rawseq '}' cap?
+  | '{' ('\\' ID (',' ID)* '\\')? cap? ID? typeparams? ('(' | LPAREN_NEW) lambdaparams? ')' lambdacaptures? (':' type)? '?'? '=>' rawseq '}' cap?
+  | '@{' ('\\' ID (',' ID)* '\\')? cap? ID? typeparams? ('(' | LPAREN_NEW) lambdaparams? ')' lambdacaptures? (':' type)? '?'? '=>' rawseq '}' cap?
   | '@' (ID | STRING) typeargs? ('(' | LPAREN_NEW) positional? named? ')' '?'?
   | '__loc'
   ;
@@ -221,8 +221,8 @@ atom
   | ('(' | LPAREN_NEW) rawseq tuple? ')'
   | ('[' | LSQUARE_NEW) ('as' type ':')? rawseq? ']'
   | 'object' ('\\' ID (',' ID)* '\\')? cap? ('is' type)? members 'end'
-  | '{' ('\\' ID (',' ID)* '\\')? cap? ID? typeparams? ('(' | LPAREN_NEW) params? ')' lambdacaptures? (':' type)? '?'? '=>' rawseq '}' cap?
-  | '@{' ('\\' ID (',' ID)* '\\')? cap? ID? typeparams? ('(' | LPAREN_NEW) params? ')' lambdacaptures? (':' type)? '?'? '=>' rawseq '}' cap?
+  | '{' ('\\' ID (',' ID)* '\\')? cap? ID? typeparams? ('(' | LPAREN_NEW) lambdaparams? ')' lambdacaptures? (':' type)? '?'? '=>' rawseq '}' cap?
+  | '@{' ('\\' ID (',' ID)* '\\')? cap? ID? typeparams? ('(' | LPAREN_NEW) lambdaparams? ')' lambdacaptures? (':' type)? '?'? '=>' rawseq '}' cap?
   | '@' (ID | STRING) typeargs? ('(' | LPAREN_NEW) positional? named? ')' '?'?
   | '__loc'
   ;
@@ -239,6 +239,14 @@ lambdacapture
   : ID (':' type)? ('=' infix)?
   ;
 
+lambdaparams
+  : lambdaparam (',' lambdaparam)*
+  ;
+
+lambdaparam
+  : parampattern (':' type)? ('=' infix)?
+  ;
+
 positional
   : rawseq (',' rawseq)*
   ;
@@ -340,7 +348,7 @@ literal
   ;
 
 param
-  : parampattern (':' type)? ('=' infix)?
+  : ID (':' type)? ('=' infix)?
   ;
 
 antlr_0

src/libponyc/ast/parser.c

@@ -73,14 +73,11 @@ DEF(defaultarg);
   RULE("default value", infix);
   DONE();
 
-// postfix [COLON type] [ASSIGN defaultarg]
+// ID [COLON type] [ASSIGN defaultarg]
 DEF(param);
   AST_NODE(TK_PARAM);
-  RULE("name", parampattern);
-  IF(TK_COLON,
-    RULE("parameter type", type);
-    UNWRAP(0, TK_REFERENCE);
-  );
+  TOKEN("parameter name", TK_ID);
+  IF(TK_COLON, RULE("parameter type", type));
   IF(TK_ASSIGN, RULE("default value", defaultarg));
   DONE();
 
@@ -344,6 +341,24 @@ DEF(object);
   SET_CHILD_FLAG(2, AST_FLAG_PRESERVE); // Members
   DONE();
 
+// parampattern [COLON type] [ASSIGN defaultarg]
+DEF(lambdaparam);
+  AST_NODE(TK_PARAM);
+  RULE("name", parampattern);
+  IF(TK_COLON,
+    RULE("parameter type", type);
+    UNWRAP(0, TK_REFERENCE);
+  );
+  IF(TK_ASSIGN, RULE("default value", defaultarg));
+  DONE();
+
+// lambdaparam {COMMA lambdaparam}
+DEF(lambdaparams);
+  AST_NODE(TK_PARAMS);
+  RULE("parameter", lambdaparam);
+  WHILE(TK_COMMA, RULE("parameter", lambdaparam));
+  DONE();
+
 // ID [COLON type] [ASSIGN infix]
 DEF(lambdacapture);
   AST_NODE(TK_LAMBDACAPTURE);
@@ -362,8 +377,9 @@ DEF(lambdacaptures);
   SKIP(NULL, TK_RPAREN);
   DONE();
 
-// LBRACE [annotations] [CAP] [ID] [typeparams] (LPAREN | LPAREN_NEW) [params]
-// RPAREN [lambdacaptures] [COLON type] [QUESTION] ARROW rawseq RBRACE [CAP]
+// LBRACE [annotations] [CAP] [ID] [typeparams] (LPAREN | LPAREN_NEW)
+// [lambdaparams] RPAREN [lambdacaptures] [COLON type] [QUESTION] ARROW rawseq
+// RBRACE [CAP]
 DEF(lambda);
   PRINT_INLINE();
   AST_NODE(TK_LAMBDA);
@@ -373,7 +389,7 @@ DEF(lambda);
   OPT TOKEN("function name", TK_ID);
   OPT RULE("type parameters", typeparams);
   SKIP(NULL, TK_LPAREN, TK_LPAREN_NEW);
-  OPT RULE("parameters", params);
+  OPT RULE("parameters", lambdaparams);
   SKIP(NULL, TK_RPAREN);
   OPT RULE("captures", lambdacaptures);
   IF(TK_COLON, RULE("return type", type));
@@ -389,8 +405,8 @@ DEF(lambda);
   DONE();
 
 // AT_LBRACE [annotations] [CAP] [ID] [typeparams] (LPAREN | LPAREN_NEW)
-// [params] RPAREN [lambdacaptures] [COLON type] [QUESTION] ARROW rawseq RBRACE
-// [CAP]
+// [lambdaparams] RPAREN [lambdacaptures] [COLON type] [QUESTION] ARROW rawseq
+// RBRACE [CAP]
 DEF(barelambda);
   PRINT_INLINE();
   AST_NODE(TK_BARELAMBDA);
@@ -400,7 +416,7 @@ DEF(barelambda);
   OPT TOKEN("function name", TK_ID);
   OPT RULE("type parameters", typeparams);
   SKIP(NULL, TK_LPAREN, TK_LPAREN_NEW);
-  OPT RULE("parameters", params);
+  OPT RULE("parameters", lambdaparams);
   SKIP(NULL, TK_RPAREN);
   OPT RULE("captures", lambdacaptures);
   IF(TK_COLON, RULE("return type", type));