Benchmarking Regexp vs. Grep vs. Hash for "finding"

reggrephash.pl

#!/usr/bin/env perl

use Benchmark qw( cmpthese );

my @prein = ( 
    qw( bar baz foo )
);
my @preout = ( qw( bar baz boo ) ) ;

my %in = (
        bar => 1,
        baz => 1,
        foo => 1,
);

my %out = (
        bar => 1,
        baz => 1,
        boo => 1,
);

my $preregin = qr/bar|baz|foo/;
my $preregout = qr/bar|baz|boo/;

cmpthese(
    10_000_000,
    {
        'PreFor' => sub  { 
            for ( @prein ) {
                return 1 if $_ eq 'foo';
            }
        },
        '!PreFor' => sub {
            for ( @preout ){ 
                return 1 if $_ eq 'foo';
            }
        },
        'For' => sub  { 
            for (qw( bar baz foo )) {
                return 1 if $_ eq 'foo';
            }
        },
        '!For' => sub {
            for (qw( bar baz boo ) ){ 
                return 1 if $_ eq 'foo';
            }
        },
        'PreGrep' => sub {
            grep { $_ eq 'foo' } @prein;
        },
        '!PreGrep' => sub {
            grep { $_ eq 'foo' } @preout;
        },
        'Grep' => sub {
            grep { $_ eq 'foo' } qw(bar baz foo);
        },
        '!Grep' => sub {
            grep { $_ eq 'foo' } qw(bar baz boo);
        },
        'PreRegexp' => sub { 'foo' =~ $preregin },
        '!PreRegexp' => sub { 'foo' =~ $preregout },
         'Regexp' => sub { 'foo' =~ m/bar|baz|foo/ },
        '!Regexp' => sub { 'foo' =~ m/bar|baz|boo/ }, 
        'Hash' => sub { defined $in{foo} },
        '!Hash' => sub { defined $out{foo} },
        'BuildHash' => sub { 
            my %hash = ( 
                bar => 1,
                baz => 1,
                foo => 1,

            );
            defined $hash{foo} 
        },
        '!BuildHash' => sub { 
            my %hash = ( 
                    bar => 1,
                    baz => 1,
                    boo => 1,
            );
            defined $hash{foo}
        },
 
    }
);


__END__
                 Rate PreRegexp BuildHash !PreFor !BuildHash !For  For PreFor Regexp !Grep Grep PreGrep !PreGrep !PreRegexp Hash !Hash !Regexp
PreRegexp   1503759/s        --      -10%    -10%       -13% -18% -35%   -37%   -37%  -42% -46%    -46%     -47%       -49% -83%  -88%    -92%
BuildHash   1663894/s       11%        --     -0%        -4%  -9% -28%   -30%   -30%  -36% -40%    -40%     -41%       -44% -82%  -87%    -91%
!PreFor     1669449/s       11%        0%      --        -4%  -9% -28%   -30%   -30%  -36% -40%    -40%     -41%       -44% -81%  -87%    -91%
!BuildHash  1730104/s       15%        4%      4%         --  -5% -26%   -27%   -27%  -33% -38%    -38%     -39%       -42% -81%  -86%    -90%
!For        1824818/s       21%       10%      9%         5%   -- -22%   -23%   -23%  -30% -34%    -35%     -35%       -38% -80%  -85%    -90%
For         2325581/s       55%       40%     39%        34%  27%   --    -2%    -2%  -10% -17%    -17%     -17%       -21% -74%  -81%    -87%
PreFor      2375297/s       58%       43%     42%        37%  30%   2%     --    -0%   -9% -15%    -15%     -16%       -20% -74%  -81%    -87%
Regexp      2380952/s       58%       43%     43%        38%  30%   2%     0%     --   -8% -15%    -15%     -15%       -20% -74%  -81%    -87%
!Grep       2597403/s       73%       56%     56%        50%  42%  12%     9%     9%    --  -7%     -7%      -8%       -12% -71%  -79%    -85%
Grep        2785515/s       85%       67%     67%        61%  53%  20%    17%    17%    7%   --     -0%      -1%        -6% -69%  -78%    -84%
PreGrep     2793296/s       86%       68%     67%        61%  53%  20%    18%    17%    8%   0%      --      -1%        -6% -69%  -78%    -84%
!PreGrep    2816901/s       87%       69%     69%        63%  54%  21%    19%    18%    8%   1%      1%       --        -5% -69%  -77%    -84%
!PreRegexp  2958580/s       97%       78%     77%        71%  62%  27%    25%    24%   14%   6%      6%       5%         -- -67%  -76%    -83%
Hash        9009009/s      499%      441%    440%       421% 394% 287%   279%   278%  247% 223%    223%     220%       205%   --  -28%    -50%
!Hash      12500000/s      731%      651%    649%       622% 585% 437%   426%   425%  381% 349%    347%     344%       322%  39%    --    -30%
!Regexp    17857143/s     1087%      973%    970%       932% 879% 668%   652%   650%  587% 541%    539%     534%       504%  98%   43%      --