#!/usr/bin/perl

use Benchmark qw(cmpthese);

$substr = join('',a..j);
$str = $substr x 90 . 'hTmL'. $substr x 2000;
print "length of search string: ",length $str, "\n";
cmpthese(-3, {
    # \A anchores at the beginning of a string, so no ^. See below (demerphq)
    #' regex ' => sub { $str =~ /^\A.{0,996}?html/si; },
    ' regex ' => sub { $str =~ /\A.{0,996}?html/si; },
    ' substr' => sub { (substr $str, 0, 1000) =~ /html/i; },
    #'!regex ' => sub { $str =~ /^\A.{0,996}?sgml/si; },
    '!regex ' => sub { $str =~ /\A.{0,996}?sgml/si; },
    '!substr' => sub { (substr $str, 0, 1000) =~ /sgml/i; },
});
__END__
length of search string: 20904
            Rate  regex   substr !substr !regex 
 regex   30996/s      --    -65%    -72%    -79%
 substr  88073/s    184%      --    -21%    -42%
!substr 111975/s    261%     27%      --    -26%
!regex  150866/s    387%     71%     35%      --