Re: Reading parser stack

[Mark Redd]

Thank you for you fast answer. I've already tried this way but it doesn't
work fine. I'm newbie, so I think I don't know something useful.

If I use a rule like that you wrote, Bison shows this message
"The identifier was: (null)".

I've red something about yylval, so if I type in Lex file:
yylval=yytext,
and so the same your rule shows me
"The identifier was: snoopy*charlie", and not only "snoopy".

What do you thing about this behaviour?


2009/4/29 Mike Aubury <address@hidden>

> Something like :
>
>
> A: B C D {
>       printf("The identifier was: %s", $2);
>  }
> | B E D {
>       printf("It wasn't an identifier...");
> }
> ;
>
>
>
>
>
> 2009/4/29 Mark Redd <address@hidden>
>
>> Hello everybody,
>> I would like to receive an hint about reading parser stack.
>>
>> Suppose my (fantasy) bison grammar is this:
>>
>> %start A
>>
>> A : B C D | B E D
>>
>> B: ID
>> C: '*'
>> D:  IDENTIFIER
>> E: '-'
>>
>> where IDENTIFIER has been defined like [a-zA-Z0-9]+ using flex.
>>
>> How can I print "the identifier was: %s" when C matches (but not when E
>> does
>> it) without rewriting the grammar?
>> In particular, I need to know what I have to write in
>> C: '*'        { printf("The identifier was: %s", ?????); }
>>
>> Note that it isn't my very problem, but it's a model of this and so I'd
>> like
>> a general answer. So I can't modify my grammar and I don't want to read
>> only
>> the last token in parser, but sometimes I'm interested in reading the last
>> n
>> tokens.
>>
>> Thank you!
>> Mark Redd
>> _______________________________________________
>> address@hidden http://lists.gnu.org/mailman/listinfo/help-bison
>>
>
>