I'm new to PEGs (but I've been parsing for a while) and I don't understand
why this..
E->XYE|ZE|
..doesn't parse "1+1-2" the way I expect (it fails):
i've tried using PackCC and I now in leg (it's more likely you know leg
than pcc)
$ ./leg g.peg -o g.c && cc g.c -o g && ./g
+fail
$ cat g.peg
#leg g.peg -o g.c && cc g.c -o g && ./g
%{
char*in="1+1-2";
#define YY_INPUT(b,r,m) *in?*(b)=*in++,putchar(*in),1:0
%}
S=E '\n';
E=x:X y:Y z:E {printf("%c%c%c\n",x,y,z);$$='E';}
|x:Z y:E {printf("%c%c\n",x,y);$$='E';}
|'' {printf("''");$$='E';}
;
Z=x:X {$$=x}
|x:Y {$$=x}
;
X= < [0-9] > {$$=*yytext;};
Y= < [-+] > {$$=*yytext;};
%%
#include <stdio.h>
int main()
{
return yyparse()?printf("success\n"),0:printf("fail\n");
}
thanks,
jack
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