Path: utzoo!attcan!uunet!samsung!aplcen!haven!wam!dkim
From: dkim@wam.umd.edu (Daeshik Kim)
Newsgroups: comp.lang.c
Subject: Re: yacc sorrows
Message-ID: <1990Feb8.035311.6506@wam.umd.edu>
Date: 8 Feb 90 03:53:11 GMT
References: <7179@arcturus>
Sender: usenet@wam.umd.edu (USENET Posting)
Reply-To: dkim@wam.umd.edu (Daeshik Kim)
Organization: Univ. of Md, College Park
Lines: 42

In article <7179@arcturus> evil@arcturus.UUCP (Wade Guthrie) writes:
>
>	%{
>	#include "y.tab.h"
>	[...]
>	%}
>	[...]
>	%%
>	auto        { return(AUTO); }
>	register    { return(REGISTER); }
>	[...]
>	"->"        { return(ARROW); }
>	";"         { return(SEMICOLON); }
>	.           { return(yytext[0]); }
>
	If you need to pass a value to 'yacc', then do the following:

	somestring	{
			yylval.sval=(char*)malloc(yyleng);
			strcpy(yylval.sval, yytext);
			return(TOKENNAME);
			}

	someinteger	{
			yylval.ival=atoi(yytext);
			return(TOKENNAME);
			}
	...

	Note that "yyval" is the type defined by "%union ....".
	In the above example, in 'yacc' def,
		%union
			{
			int ival;
			char *sval;
			}

	scan over c code from lex.
--
	Daeshik Kim	H: (301) 445-0475/2147 O: (703) 689-5878
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