# a:  if( $s =~ m[(lazy)] ){ $found=$1 }
Compiling REx "(lazy)"
Final program:
   1: OPEN1 (3)
   3:   EXACT <lazy> (5)
   5: CLOSE1 (7)
   7: END (0)
anchored "lazy" at 0 (checking anchored) minlen 4
Matching REx "(lazy)" against "the quick brown fox jumps over the lazy dog"
Intuit: trying to determine minimum start position...
  Found anchored substr "lazy" at offset 35...
  (multiline anchor test skipped)
  try at offset...
Intuit: Successfully guessed: match at offset 35
  35 < the > <lazy dog>      |  1:OPEN1(3)
  35 < the > <lazy dog>      |  3:EXACT <lazy>(5)
  39 <the lazy> < dog>       |  5:CLOSE1(7)
  39 <the lazy> < dog>       |  7:END(0)
Match successful!
Freeing REx: "(lazy)"
# b:  $found = 'lazy' if 1+index( $s, 'lazy' );
# c:  if( $s =~ m[lazy] ){ $found=$& }
Compiling REx "lazy"
Final program:
   1: EXACT <lazy> (3)
   3: END (0)
anchored "lazy" at 0 (checking anchored isall) minlen 4
Matching REx "lazy" against "the quick brown fox jumps over the lazy dog"
Intuit: trying to determine minimum start position...
  Found anchored substr "lazy" at offset 35...
  (multiline anchor test skipped)
  try at offset...
Intuit: Successfully guessed: match at offset 35
Freeing REx: "lazy"
       Rate    a    c    b
a 2038631/s   -- -50% -75%
c 4089154/s 101%   -- -49%
b 8013601/s 293%  96%   --

##</code><code>##

use strict;
use Benchmark 'cmpthese';
use vars '$s';
$s='the quick brown fox jumps over the lazy dog'; 
my $found;

my %benchmarks = (
    a => q[ if( $s =~ m[(lazy)] ){ $found=$1 } ],
    b => q[ $found = 'lazy' if 1+index( $s, 'lazy' ); ],
    c => q[ if( $s =~ m[lazy] ){ $found=$& } ],
);

{
    use re 'debug';
    for (sort keys %benchmarks) {
        print "# $_: $benchmarks{$_}\n";
        undef $found;
        my $code = eval qq{sub { $benchmarks{$_} } }
            or die "Couldn't compile benchmark $_: $@";
        $code->();
        $found eq 'lazy'
            or die "Unexpected results: [$found] vs. 'lazy'";
    };
};

cmpthese( -1, \%benchmarks);