reg debugging shift/reduce and reduce/reduce conflicts

sam_cit@yahoo.co.in
6 Apr 2007 00:03:47 -0400

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reg debugging shift/reduce and reduce/reduce conflicts sam_cit@yahoo.co.in (2007-04-06)
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From: sam_cit@yahoo.co.in
Newsgroups: comp.compilers
Date: 6 Apr 2007 00:03:47 -0400
Organization: Compilers Central
Keywords: question, yacc
Posted-Date: 06 Apr 2007 00:03:47 EDT

Hi Everyone,


  I'm trying to develop a parser for a vCard decoder, i'm using lex and
yacc. And to satisfy few type pf vCards i modifed a grammar and it
resulted in shift/reduce and reduce/reduce conflicts. I used -v option
of yacc to generate a y.output file and I was able to understand only
a bit of the file...


                141: shift/reduce conflict (shift 221, red'n 239) on 10


I understand that the conflict is in 141 state and yacc is in a
confusion on token 10 as to whether shift to 221 state or reduce using
a rule 239...


    this is followed by some grammar rules from Yacc and then followed
by


    20 shift 239
    200 reduce 239
    67 shift 221


  I do not understand this part at all... Please help me in debugging
these errors...


Thanks in advance!!!


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