code review 113120043: cmd/gc: implement 'for range x {'

src/cmd/gc/go.y

 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 /*
  * Go language grammar.
  *
  * The Go semicolon rules are:
  *
  *  1. all statements and declarations are terminated by semicolons.
@@ skipping 595 matching lines @@
                 $$->list = $1;
                 $$->etype = 0;  // := flag
         }
 |       expr_list LCOLAS LRANGE expr
         {
                 $$ = nod(ORANGE, N, $4);
                 $$->list = $1;
                 $$->colas = 1;
                 colasdefn($1, $$);
         }
+|       LRANGE expr
+        {
+                $$ = nod(ORANGE, N, $2);
+                $$->etype = 0; // := flag
+        }
 
 for_header:
         osimple_stmt ';' osimple_stmt ';' osimple_stmt
         {
                 // init ; test ; incr
                 if($5 != N && $5->colas != 0)
                         yyerror("cannot declare in the for-increment");
                 $$ = nod(OFOR, N, N);
                 if($1 != N)
                         $$->ninit = list1($1);
@@ skipping 1581 matching lines @@
 static void
 fixlbrace(int lbr)
 {
         // If the opening brace was an LBODY,
         // set up for another one now that we're done.
         // See comment in lex.c about loophack.
         if(lbr == LBODY)
                 loophack = 1;
 }