bison look ahead token problem

"Avin Patel" <avin_comp@yahoo.com>
11 Dec 2001 21:32:22 -0500

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bison look ahead token problem avin_comp@yahoo.com (Avin Patel) (2001-12-11)
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From: "Avin Patel" <avin_comp@yahoo.com>
Newsgroups: comp.compilers
Date: 11 Dec 2001 21:32:22 -0500
Organization: Compilers Central
Keywords: yacc, parse, comment
Posted-Date: 11 Dec 2001 21:32:22 EST

Hi,
I have made a seperate parser for reading the text buffer.
Now the rule is completed by just reading only part of that text buffer,
than I forcefully complete the rule without error by calling YYACCEPT, but
at the end of the rule it reads one more extra token, How can i stop it to
read any further token before YYACCEPT.
I mean to say
I have text buffer like
SEQUENCE { c INTEGER}, INTEGER


Now in this texts I am completing 2 rules
one is SEQUENCE { c INTEGER}
another is INTEGER
seperator is comma
But when I use my parser than at the end of the rule it reads one more token
',' & I am missing by my seperator.


I am not doing like
rule:
        rule1
        | rule1lisr ',' rule1


I am just reading reading rule1, than doing some my own work, than again I
am coming back, assigning lexer to parser & reading another rule.
Thank you
[That's how LALR parsers work. If you don't want readahead at the end,
you'll have to figure out some way for the lexer to know that it's done.
-John]


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