On Sat, 27 Apr 2013, Martin Gregorie wrote:
Question to JH: I can see that portmanteau rules on high volume sites
would benefit from the (?=x) optimisation, but so would a lot of rules
that use regexes containing alternations. So, is there any possibility
of slotting it into the SA rule compiler rather than me implementing it
as part of my portmanteau rule generator when doing the latter would
limit its use to a subset of rules that might benefit.
The internal compiler within SA itself, or the external tool that compiles
rules?
The former is just essentially generation of perl code for the rule
evaluation and reusing that. It doesn't do any analysis or rule-combining
that would allow leverage of this.
I have no familiarity with the latter, so I couldn't comment.
It seems to me that only-the-fly generation of (?=x)(xa|xb|xc) or x(a|b|c)
optimizations of alterations is a fairly non-trivial task given something
other than alternations built from a sorted set of substrings or sub-REs -
and in fact, now that I think about it, that sort of optimization is
properly the job of an optimizer for the RE parser built into perl... the
programmer writing the REs shouldn't have to worry about doing something
(fairly) obvious like that. Think of it the same way you think about the
query plan optimizer in a database engine.
--
John Hardin KA7OHZ http://www.impsec.org/~jhardin/
jhar...@impsec.org FALaholic #11174 pgpk -a jhar...@impsec.org
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