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From: flee@cs.psu.edu (Felix Lee)
Newsgroups: comp.lang.perl
Subject: Re: Sluggish patterns.
Message-ID: <rmGzlih1@cs.psu.edu>
Date: 5 Apr 91 07:31:09 GMT
References: <1991Apr1.181801.16850@uvaarpa.Virginia.EDU>
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> eval "sub cookie { &eat() if /$cookie/o; }";
> eval "sub monster { &run() if /$monster/o; }";
> while (! $done) {
> 	&begin();
> 	&cookie;
> 	&monster;
> 	&end();
> }

Okay.  Now how do you make it recursive?
	sub ctw {
		local($cookie, $monster) = @_;
		while (! $done) {
			&eat() if /$cookie/;
			&run() if /$monster/;
		}
	}
$cookie and $monster change infrequently, but they may change in
either &eat or &run.  Either &eat or &run may call &ctw recursively
with random parameters.

It doesn't look very hard to change Perl so it does a cheap string
compare before it recompiles run-time patterns.
--
Felix Lee	flee@cs.psu.edu