OK, I forgot the attachment. Moreover, the below ambiguity arises with the string: /"hello." people./ (without '/').
sorry. Alessandro
demo.tgz
Description: Binary data
Alessandro Di Marco <[EMAIL PROTECTED]> writes: Hi all. I was trying to create a GLR grammar for natural languages when I stuck on the following s/r ambiguity. Ambiguity detected. Option 1, text -> <Rule 2, tokens 1 .. 6> text -> <Rule 2, tokens 1 .. 3> text <empty> sentence -> <Rule 4, tokens 1 .. 3> DOUBLEQ <tokens 1 .. 1> WORD <tokens 2 .. 2> EOL <tokens 3 .. 3> sentence -> <Rule 4, tokens 4 .. 6> DOUBLEQ <tokens 4 .. 4> WORD <tokens 5 .. 5> EOL <tokens 6 .. 6> Option 2, text -> <Rule 2, tokens 1 .. 6> text -> <Rule 2, tokens 1 .. 4> text <empty> sentence -> <Rule 5, tokens 1 .. 4> DOUBLEQ <tokens 1 .. 1> WORD <tokens 2 .. 2> EOL <tokens 3 .. 3> DOUBLEQ <tokens 4 .. 4> sentence -> <Rule 3, tokens 5 .. 6> WORD <tokens 5 .. 5> EOL <tokens 6 .. 6> ERROR! Cleanup: popping token $end () Cleanup: popping unresolved nterm text () Cleanup: popping unresolved nterm sentence () Cleanup: popping token EOL () Cleanup: popping token WORD () Cleanup: popping token DOUBLEQ () Cleanup: popping unresolved nterm text () Cleanup: popping unresolved nterm sentence () Cleanup: popping token EOL () Cleanup: popping token WORD () Cleanup: popping token DOUBLEQ () Cleanup: popping nterm text () Cleanup: popping token $end () It seems that both the options above are valid, so they need disambiguation. I've tried '%dprec' (as also suggested in bison manual), but without any success. For your convenience I have stripped down the grammar to the below few lines, which produce the above result. text: /* empty */ | text sentence ; sentence: WORD EOL | DOUBLEQ WORD EOL | DOUBLEQ WORD EOL DOUBLEQ ; where: [[:alnum:]]+ return WORD; \" return DOUBLEQ; \. return EOL; I've also attached a q&d demo of the problem; simply untar, make and execute './demo'. Tested both on bison 2.2 and 2.3... won't work! :-) Thanks in advance. Best, Alessandro -- Catch 22 - Joseph Heller
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