[Python-Dev] Re: Automatic flex interface for Python?

Eric S. Raymond esr@thyrsus.com
Tue, 20 Aug 2002 23:20:18 -0400

Skip Montanaro <skip@pobox.com>:
> This reminds me of something which tickled my interesting bone the other
> day.  The SpamAssassin folks are starting to look at Flex for much faster
> regular expression matching in situations where large numbers of static re's
> must be matched.

*snort* Took'em long enough.  No, I shouldn't be snarky.  Flex is only
obvious to Unix old-timers -- the traditions that gave rise to it have
fallen into desuetitude in the last decade.

> ...insert Flex rules into the string, call a slightly higher level
> function which calls flex to generate the scanner code and use a
> slightly different bit of module sticky stuff to make it callable
> from Python.

Lexers are painful in Python.  They hit the language in a weak spot
created by the immutability of strings.  I've found this an obstacle
more than once, but then I'm a battle-scarred old compiler jock who
attacks *everything* with lexers and parsers.
		<a href="http://www.tuxedo.org/~esr/">Eric S. Raymond</a>