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Subject: Re: [boost] [regex, xpressive] interesting(?) perf benchmark
From: Joel de Guzman (joel_at_[hidden])
Date: 2010-06-07 23:08:15

On 6/8/10 8:34 AM, Eric Niebler wrote:
> On 6/7/2010 8:01 PM, Joel de Guzman wrote:
>> On 6/8/10 12:10 AM, Eric Niebler wrote:
>>> An interesting research project would be to investigate whether
>>> xpressive's hybrid static/dynamic NFA design can be applied to DFAs
>>> as well, with similar perf wins. This would be a non-trivial
>>> undertaking, like completely reimplementing xpressive.
>> Just to remind you, there's a very good DFA implementation
>> underneath Spirit Lex. The interface is not perfect (Ben has
>> requested for some input in that area), but the implementation is
>> very good. Spirit Lex is proto on top of lexertl (Ben's work). We
>> find it to be one of the fastest lexer, close to performance to the
>> fastest (RE2C) which is a code-gen that generates a humongous
>> switch.
> I haven't forgotten. IIRC, lexertl is like dynamic xpressive: it accepts
> strings as input and builds a FSA. I was speculating about what the
> lexertl equivalent of static xpressive would look like and whether it
> would be even faster. Then static xpressive could use static lexertl for
> simple regexes, and dynamic xpressive could use the dynamic one.

That's an awesome idea!


Joel de Guzman

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