Brothers and Sisters,

Suppose I currently have something like this: 

my @regex = map {qr /$_/ } qw/
    regex1
    regex2
    .
    .
    regex 140
/;

# @array has 20000 entries
foreach $i (@array) {

   for $x (@regex) {
       push @match, $x if $i =~ m/$x/;
   }

}

[download]

There must be a more efficient way to do this. I was thinking it would be better to loop through @regex first: 

foreach $x (@regex){

   @bad_matches = grep ! m/$x/, @array;

[download]

After the grep how would I remove the entries in @bad_matches from @array before the next $x? Would this be faster?

Am I on the right track? Would using the Parallel::ForkManager somehow help? Does anyone have other suggestions?

Neil Watson
watson-wilson.ca

In reply to Efficiency: Foreach loop and multiple regexs by neilwatson

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.