Exit while loop on first match

ybiC has asked for the wisdom of the Perl Monks concerning the following question:

The following chunklet parses markup for bolded numbers, and kicks out of the while loop on the first match. Works fine, lasts 'long time. But the ++$match seems a bit, uhm, mechanical, maybe? Might there be smoother ways to facilitate kicking out on the first match?
    cheers,
    Don
    striving toward Perl Adept
    (it's pronounced "why-bick")

my $match = 0;
my $pb  = HTML::TokeParser->new(\$content);
while($pb->get_tag('b', '/b') && $match < 1){
  my $tb = $pb->get_text();
  if($tb =~ /^\d+$/){
    $num = $tb;
    ++$match;
  }
}
[download]

_{ps - kudos to da loony sleepfree one for his HTML::TokeParser tutorial}

Comment on Exit while loop on first match Download Code

Replies are listed 'Best First'.
Re: Exit while loop on first match by Fletch (Bishop) on Apr 30, 2002 at 15:53 UTC
`last if $tb =~ /^\d+$/; ## FISH` [download]	[reply] [d/l]
Re: Exit while loop on first match by japhy (Canon) on Apr 30, 2002 at 16:09 UTC
You could use `last`, or at least an oppositely-named variable: `my $no_match = 1; while ($pb->... and $no_match) { # ... $no_match = 0; }` [download] _____________________________________________________ Jeff`[japhy]`Pinyan: Perl, regex, and perl hacker, who'd like a (from-home) job `s++=END;++y(;-P)}y js++=;shajsj<++y(p-q)}?print:??;`	[reply] [d/l]
Re: Exit while loop on first match by erikharrison (Deacon) on Apr 30, 2002 at 17:00 UTC
The previous suggestions to use `last` are excellent. A loop label might help: `MATCH: while { ... last MATCH; }` [download] Also, I use the phrase "synthectic code" to refer to architectural code: hacks that just exist as a frame to make the algorithm work. This is a phrase stolen from a perl.com article, http://www.perl.com/pub/a/2000/06/commify.html Cheers, Erik Update: Forgot a colon . . . boy is my face red . . .	[reply] [d/l] [select]
Re: Exit while loop on first match by jynx (Priest) on Apr 30, 2002 at 21:16 UTC
Possibly not the style you wish to go with, But in such a situation i would use a bare block loop. Mostly i use them when there are multiple loop modifiers that i want to simplify, and this (sort of) fits that description. In any event, it gets rid of extra variables... `# note this is completely untested... my $match = 0; my $pb = HTML::TokeParser->new(\$content); { $pb->get_tag('b', '/b'); my $tb = $pb->get_text(); if ($tb =~ /^\d+$/) { $num = $tb; last; } redo; }` [download] something like that maybe, jynx	[reply] [d/l]


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