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Re: page fault when YYFAIL explicitly called

From: Stanislav Lang
Subject: Re: page fault when YYFAIL explicitly called
Date: Fri, 15 Nov 2013 21:20:57 +0100 (CET)

The problem was, that when YYFAIL was called, there was printed a default 
message (if verbose option was set to 1) into console in form eg (
"unexpected token END_OF_LINE there was expected token ENDIF or ELSEIF", 
etc.), but YYERROR did not support this default messages in version 2.4.

It would be good for me, to have an option to enable this default error 
messages in YYERROR. Now I try to use Bison 3 int the next step, and I will 
see. It will be better, when we will talk about the last version, I did not 
try it yet. 

The main purpose of my message was, that if you would make a revision for 
version 2.4, that there was a small problem, that is easy to remove (only 
set yylen=0 on the beginning of YYFAIL routine). 

On the other side, it is not big problem for my code, I can solve it.  



"Hi Stanislav,

Please keep the list in CC, for the records.

Le 8 nov. 2013 à 20:04, Stanislav Lang <address@hidden> a écrit :

> Thanks for the answer... 
> i know that it is recommended to use YYERROR, because it is more effective
and safe. But YYFAIL prints informations about that, which token appeared 
and which token was expected.

How about calling yyerror yourself?

> When YYFAIL will be not more supported, it is not so big problem, I will 
make some extension for yyerror function, to be able to print informations 
about tokens. Or will be this functionality made for some next version of 
Bison by Bison team?

Actually YYFAIL is already removed in Bison 3.0. Could you
describe what feature you'd like to see? Often when one wants
to raise a syntax error, one can forge better error messages
that the default ones. That's why, imho, YYFAIL was not so
much used."

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