Re: push parser

[Paul Eggert]

Frans Englich <address@hidden> writes:

> How about using an enum?

Sure, that'd be fine.  I installed this:

2006-09-21  Paul Eggert  <address@hidden>

        * data/push.c (YYPUSH_MORE): Make it an enum instead.
        (yypushparse): Use YYPUSH_MORE instead of the mystery constant.
        Adjust white space and comments to match GNU style better.

--- data/push.c.~1.2.~  2006-09-20 21:49:30.000000000 -0700
+++ data/push.c 2006-09-21 10:43:45.000000000 -0700
@@ -973,7 +973,7 @@ yysyntax_error (char *yyresult, int yyst
 
 ]b4_push_if([
 struct yypvars;
-#define YYPUSH_MORE 4
+enum { YYPUSH_MORE = 4 };
 ]b4_c_function_decl([yychar_set], [void], [[struct yypvars *YYPVARS], 
[YYPVARS]], [[int yychar], [yychar]])[
 ]b4_c_function_decl([yylval_set], [void], [[struct yypvars *YYPVARS], 
[YYPVARS]], [[YYSTYPE yylval], [yylval]])[
 #ifdef YYLTYPE_IS_TRIVIAL
@@ -1055,18 +1055,16 @@ m4_define([b4_declare_yyparse_variables]
     /* The variables used to return semantic value and location from the
        action routines.  */
     YYSTYPE yyval;
-    /* Used to determine if this is the first time this instance has 
+    /* Used to determine if this is the first time this instance has
        been used.  */
     int yynew;]b4_locations_if([YYLTYPE yyloc;])[
   };
 
-/* Init the parser data structure. Use malloc, should perhaps use a 
-   system dependent equivalent function.  */
-void* 
+/* Initialize the parser data structure.  */
+void *
 yypvarsinit (void)
 {
-  struct yypvars *pv;
-  pv= (struct yypvars *) malloc(sizeof(struct yypvars));
+  struct yypvars *pv = (struct yypvars *) malloc (sizeof *pv);
   pv->yystate = 0;
   pv->yyresult = -1;
   pv->yyerrstatus = 0;
@@ -1098,9 +1096,8 @@ yypvarsinit (void)
   pv->yynew = 1;
 
 ]b4_locations_if([  pv->yylsp = pv->yyls;])[
-  /* Init parser variables */
-    
-  return (void*) pv;
+
+  return (void *) pv;
 }
 
 void
@@ -1239,41 +1236,41 @@ m4_ifdef([b4_dollar_dollar_used],[[  yyv
 m4_ifdef([b4_at_dollar_used], [[  yylsp[0] = yylloc;
 ]])dnl
 [  ]b4_push_if([
-        /* Initialize the locals to the current context. */
-       yychar        = pv->yychar;
-       yylval        = pv->yylval;
-       yynerrs       = pv->yynerrs;
+       /* Initialize the locals to the current context. */
+       yychar = pv->yychar;
+       yylval = pv->yylval;
+       yynerrs = pv->yynerrs;
        ]b4_locations_if([
-       yylloc        = pv->yylloc;])[
+       yylloc = pv->yylloc;])[
 
-        yystate              = pv->yystate;
-       yyn           = pv->yyn;
-       yyresult      = pv->yyresult;
-       yyerrstatus   = pv->yyerrstatus;
-       yytoken       = pv->yytoken;
+       yystate = pv->yystate;
+       yyn = pv->yyn;
+       yyresult = pv->yyresult;
+       yyerrstatus = pv->yyerrstatus;
+       yytoken = pv->yytoken;
 #if YYERROR_VERBOSE
-       yymsgbuf_ptr  = pv->yymsgbuf_ptr;
-       yymsg         = pv->yymsg;;
-       yymsg_alloc   = pv->yymsg_alloc;
-#endif
-       yyssa_ptr     = pv->yyssa_ptr;
-       yyss          = pv->yyss;
-       yyssp         = pv->yyssp;
+       yymsgbuf_ptr = pv->yymsgbuf_ptr;
+       yymsg = pv->yymsg;;
+       yymsg_alloc = pv->yymsg_alloc;
+#endif
+       yyssa_ptr = pv->yyssa_ptr;
+       yyss = pv->yyss;
+       yyssp = pv->yyssp;
 
-       yyvs          = pv->yyvs;
-       yyvsp         = pv->yyvsp;
+       yyvs = pv->yyvs;
+       yyvsp = pv->yyvsp;
 
        ]b4_locations_if([[  /* The location stack.  */
-       yyls          = pv->yyls;
-       yylsp         = pv->yylsp;
+       yyls = pv->yyls;
+       yylsp = pv->yylsp;
 
        yyerror_range_ptr = pv->yyerror_range_ptr;]])[
 
-        yystacksize   = pv->yystacksize;
-       yylen         = pv->yylen;
-       yyval         = pv->yyval;
+       yystacksize = pv->yystacksize;
+       yylen = pv->yylen;
+       yyval = pv->yyval;
        ]b4_locations_if([yyloc = pv->yyloc;])[
-      if (pv->yynew == 0) 
+      if (pv->yynew == 0)
       {
        goto gottoken;
       }
@@ -1382,46 +1379,46 @@ yybackup:
   if (yychar == YYEMPTY)
     {
       ]b4_push_if([
-        YYDPRINTF ((stderr, "Return for a new token:\n"));
-        yyresult= 4;
-        /* Initialize the locals to the current context. */
-       pv->yychar            = yychar;
-       pv->yylval            = yylval;
-       pv->yynerrs           = yynerrs;
+       YYDPRINTF ((stderr, "Return for a new token:\n"));
+       yyresult = YYPUSH_MORE;
+       /* Initialize the locals to the current context. */
+       pv->yychar = yychar;
+       pv->yylval = yylval;
+       pv->yynerrs = yynerrs;
        ]b4_locations_if([
-       pv->yylloc            = yylloc;])[
+       pv->yylloc = yylloc;])[
 
-        pv->yystate          = yystate;
-       pv->yyn               = yyn;
-       pv->yyresult          = yyresult;
-       pv->yyerrstatus       = yyerrstatus;
-       pv->yytoken           = yytoken;
+       pv->yystate = yystate;
+       pv->yyn = yyn;
+       pv->yyresult = yyresult;
+       pv->yyerrstatus = yyerrstatus;
+       pv->yytoken = yytoken;
 #if YYERROR_VERBOSE
-       pv->yymsgbuf_ptr      = yymsgbuf_ptr;
-       pv->yymsg             = yymsg;;
-       pv->yymsg_alloc       = yymsg_alloc;
-#endif
-       pv->yyssa_ptr         = yyssa_ptr;
-       pv->yyss              = yyss;
-       pv->yyssp             = yyssp;
+       pv->yymsgbuf_ptr = yymsgbuf_ptr;
+       pv->yymsg = yymsg;;
+       pv->yymsg_alloc = yymsg_alloc;
+#endif
+       pv->yyssa_ptr = yyssa_ptr;
+       pv->yyss = yyss;
+       pv->yyssp = yyssp;
 
-       pv->yyvs              = yyvs;
-       pv->yyvsp             = yyvsp;
+       pv->yyvs = yyvs;
+       pv->yyvsp = yyvsp;
 
        ]b4_locations_if([[  /* The location stack.  */
-       pv->yyls              = yyls;
-       pv->yylsp             = yylsp;
+       pv->yyls = yyls;
+       pv->yylsp = yylsp;
        pv->yyerror_range_ptr = yyerror_range_ptr;]])[
 
-        pv->yystacksize              = yystacksize;
-       pv->yylen             = yylen;
-       pv->yyval             = yyval;
+       pv->yystacksize = yystacksize;
+       pv->yylen = yylen;
+       pv->yyval = yyval;
        ]b4_locations_if([pv->yyloc = yyloc;])[
-        return yyresult;
+       return yyresult;
 gottoken:
-        YYDPRINTF((stderr, "Reading a token: "));],[
+       YYDPRINTF((stderr, "Reading a token: "));],[
        YYDPRINTF ((stderr, "Reading a token: "));
-        yychar = YYLEX;])[
+       yychar = YYLEX;])[
     }
 
   if (yychar <= YYEOF)
@@ -1781,7 +1778,7 @@ typedef struct YYLTYPE
 #endif
 
 ]b4_push_if([struct ]b4_prefix[pvars;
-#define YYPUSH_MORE 4])[
+enum { YYPUSH_MORE = 4 };])[
 ]b4_pure_if([],
           [extern YYLTYPE b4_prefix[]lloc;])
 )dnl b4_locations_if