From: sof <unknown>
Date: Fri, 15 Jan 1999 18:32:23 +0000 (+0000)
Subject: [project @ 1999-01-15 18:32:22 by sof]
X-Git-Tag: Approx_2487_patches~78
X-Git-Url: http://git.megacz.com/?a=commitdiff_plain;ds=sidebyside;h=5aeafc40cf1dd067fc2627b9c6bfe8d9e074d079;p=ghc-hetmet.git

[project @ 1999-01-15 18:32:22 by sof]
Be a little bit more user-friendly when encountering record puns,
which is no longer supported by Haskell. Instead of a Plain Old Parse
Error, print out

  foo.hs:11:11: Haskell 98 does not support 'punning' on records ....

Hopefully that should give the user a big enough hint at what's
going wrong..
---

diff --git a/ghc/compiler/parser/hsparser.y b/ghc/compiler/parser/hsparser.y
index 0b5208a..4bd6d8b 100644
--- a/ghc/compiler/parser/hsparser.y
+++ b/ghc/compiler/parser/hsparser.y
@@ -61,6 +61,11 @@ extern int modulelineno;
 extern int startlineno;
 extern int endlineno;
 
+/* Local helper functions */
+static void checkinpat        PROTO((void));
+static void punningNowIllegal PROTO((void));
+
+
 /**********************************************************************
 *                                                                     *
 *                                                                     *
@@ -1090,8 +1095,9 @@ rbinds1	:  rbind				{ $$ = lsing($1); }
 	|  rbinds1 COMMA rbind			{ $$ = lapp($1,$3); }
 	;
 
-rbind  	:  qvar EQUAL exp			{ $$ = mkrbind($1,mkjust($3)); }
-;	
+rbind  	: qvar					{ punningNowIllegal();	       }
+	| qvar EQUAL exp			{ $$ = mkrbind($1,mkjust($3)); }
+	;	
 
 texps	:  exp					{ $$ = lsing($1); }
 	|  exp COMMA texps			{ $$ = mklcons($1, $3) }
@@ -1298,7 +1304,8 @@ rpats1	: rpat					{ $$ = lsing($1); }
 	| rpats1 COMMA rpat			{ $$ = lapp($1,$3); }
 	;
 
-rpat	:  qvar EQUAL pat			{ $$ = mkrbind($1,mkjust($3)); }
+rpat	: qvar					{ punningNowIllegal();         } 
+	| qvar EQUAL pat			{ $$ = mkrbind($1,mkjust($3)); }
 	;
 
 
@@ -1622,13 +1629,18 @@ vccurly1:
 **********************************************************************/
 
 
-void
-checkinpat()
+static void checkinpat()
 {
   if(pat_check)
     hsperror("pattern syntax used in expression");
 }
 
+static void punningNowIllegal()
+{
+  hsperror("Haskell 98 does not support 'punning' on records");
+}
+
+
 /* The parser calls "hsperror" when it sees a
    `report this and die' error.  It sets the stage
    and calls "yyerror".
diff --git a/ghc/compiler/parser/utils.h b/ghc/compiler/parser/utils.h
index fe8bd73..7b419d4 100644
--- a/ghc/compiler/parser/utils.h
+++ b/ghc/compiler/parser/utils.h
@@ -92,7 +92,6 @@ void	 hsindentoff PROTO((void));
 
 int	 checkfixity PROTO((char *));
 void	 checksamefn PROTO((tree));
-void	 checkinpat PROTO((void));
 
 void	 expORpat PROTO((int,tree));
 /* the "int" arg says what we want; it is one of: */