narainhere: Hi monks, I would like to do a regex on a string, to see if it matches any of the strings in a array

After reading the solutions here, I was tempted to
post a second contribution (which I do now).

The topic is interesting because so many
ways exist to solve it. My question was then:
what are they worth in real code. Stressing the
point of the OP: "to see if it matches any of the strings in a array",
it's clear that the grep/map-solutions do too much here.
But what about the regex-only solution?

Here's my first attempt to get behind that: 
use strict;
use warnings;
use List::Util qw'first reduce';
use Benchmark qw'cmpthese timethese';

 my @arr = qw' cool guy here ' x 1;
 my $str = '100 WORDS ' x 50 . 'I am cool';
 my @invocation=(0)x5;


 my $results = timethese(0,  {
 'word_altn' => sub {
                   local $" = '|';
                   if( $str =~ /@arr/ ) {
                      ++$invocation[0]; # print "Matched\n"
                   }
                },
 'block_grep' => sub {
                   if( grep { index($str, $_) !=-1 } @arr) {
                      ++$invocation[1]; # print "Matched\n"
                   }  
                },
 'expr_grep' => sub {
                   if( grep index($str, $_) !=-1, @arr) {
                      ++$invocation[2]; # print "Matched\n"
                   }
                },
 'list_util_index' => sub {
                   if( first { index($str, $_) != -1 }, @arr ) {
                      ++$invocation[3]; #print "Matched\n"
                   }
                },
 'list_util_regex' => sub {
                   if( first { $str =~ /$_/ }, @arr ) {
                      ++$invocation[4]; #print "Matched\n"
                   }
                }
 }, 'none' );
 
 print "@invocation\n";
 die unless 5 == grep $_>0, @invocation;
 
 cmpthese $results;

[download]
On my Linux box (5.8.8), this will produce: 
42598 1157019 1349175 990717 1135313
                    Rate word_altn list_util_index list_util_regex blo
+ck_grep expr_grep
word_altn        10213/s        --            -96%            -97%    
+   -97%      -97%
list_util_index 274237/s     2585%              --             -8%    
+   -16%      -20%
list_util_regex 299705/s     2835%              9%              --    
+    -8%      -13%
block_grep      325087/s     3083%             19%              8%    
+     --       -5%
expr_grep       342754/s     3256%             25%             14%    
+     5%        --

[download]
On larger strings *or* larger comparison word arrays,
the List::Util based solutions will tend to win
by a margin.

Regards

mwa

In reply to Re: Mathching an array in regex by mwah
in thread Mathching an array in regex by narainhere

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.