Re: grammar problems
[email protected] ((Randal L. Schwartz)) 21 May 2004 15:29:00 -0700
| Newsgroups | perl.recdescent |
|---|---|
| Organization | Stonehenge Consulting Services; Portland, Oregon, USA |
| Message-ID | <[email protected]> |
>>>>> "Jonas" == Jonas Wolf <[email protected]> writes: Jonas> I would like to parse boolean queries like the following: Jonas> <=> means the two queries represent the same structure Jonas> this and that <=> this that Jonas> this or that Jonas> a b or c d <=> (a b) or (c d) <=> (a and b) or (c and d) Jonas> "this phrase" word <=> "this phrase" and word Jonas> abstract = error or content = mistake <=> (abstract = error) or (content = Jonas> mistake) Jonas> ... I'm a bear of very little brain and you're using those fancy-schmancy words like "conjunction" and "disjunction", but I'd structure that as: disjunction: <leftop: conjunction "or" conjunction> conjunction: <leftop: atom optional_and atom> optional_and: "and" | "" atom: "(" disjunction ")" | equality | word | quoted_phrase word: /\w+/ quoted_phrase: /"[^"]+"/ equality: word "=" word -- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <[email protected]> <URL:http://www.stonehenge.com/merlyn/> Perl/Unix/security consulting, Technical writing, Comedy, etc. etc. See PerlTraining.Stonehenge.com for onsite and open-enrollment Perl training!