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Re: Golf (Inspired): Repeated Phrases

by Corion (Patriarch)
on May 10, 2001 at 20:05 UTC ( [id://79450] : note . print w/replies, xml ) Need Help??

in reply to Golf (Inspired): Repeated Phrases

My solution is not really a competitor, since I'm not that familiar with Perl Golf customs, so bear with me.

use strict; sub f { my ($a,$b,$m,$n) = @_; my (@r) = (); my $l = " $a! $b"; while($l =~ s/(.*?)(( \w+){$m,$n} )(.*!.*\2.*)/ $1 =$4/) { push @r, $2; }; @r };

Why I'm posting this at all is, that a previous version exhibited unanticipated (by me, that is) behaviour :

# Previous version : my $l = " $a! $b"; while($l =~ s/(.*)(( \w+){$m,$n} )(.*!.*\2.*)/ $1 =$4/) { push @r, $2; }; @r

That version only found the $m-word matches, because the greedy (.*) at the beginning forced the RE engine to work its way backwards through the string. As soon as I sacrificed another character, this problem went away. I haven't given the golfing much thought (at work, I can only think about concepts, not byte-fiddle with REs without raising suspicions ... ).