Re: Regular expressions speedup

Tony Finch <dot@dotat.at>
10 Aug 2005 11:53:24 -0400

          From comp.compilers

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From: Tony Finch <dot@dotat.at>
Newsgroups: comp.compilers
Date: 10 Aug 2005 11:53:24 -0400
Organization: dotat labs
References: 05-08-023 05-08-029
Keywords: lex, DFA

Cleo Saulnier <cleos@nb.sympatico.ca> wrote:
>
>> [If you really care about speed, why not turn the NFA into a DFA so
>> you don't have to do multiple states and backtracking? -John]
>
>Well, I've looked at DFA and it's great if you don't have
>backreferences.


The way Gnu Grep handles this problem is by using a DFA to find
matches, then post-processing them to check for the consistency
of backrefs.


Tony.
--
f.a.n.finch <dot@dotat.at> http://dotat.at/
ARDNAMURCHAN POINT TO CAPE WRATH INCLUDING THE OUTER HEBRIDES: VARIABLE
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