s/iter   regex    map   hash
regex   119     --    -71%  -100%
map     34.7   243%     --   -99%
hash   0.443 26705%  7715%     --
10000:10000:10000

##</code><code>##

print join '|', split /\s/, '         the  quick    brown    fox     jumps          '
|||||||||the||quick||||brown||||fox|||||jumps

print join '|', split /\s+/, '         the  quick    brown    fox     jumps          '
|the|quick|brown|fox|jumps

print join '|', split ' ', '         the  quick    brown    fox     jumps          '
the|quick|brown|fox|jumps


##</code><code>##

#! perl -slw
use strict;
use Benchmark qw[ cmpthese ];

sub rndStr  ($@) { join '', @_[ map{ rand @_ } 0 .. shift ] }
sub shuffle (\@) { my $r=pop; $a = $_ + rand @{$r} - $_ and @$r[$_, $a] = @$r[$a, $_] for 0..$#{$r}; }

our @words = map{ rndStr 3 + rand 6, 'A' .. 'Z', 'a'..'z' } 1 .. 10000;
our $string = join ' ', @words;
shuffle @words;

our %hash; @hash{@words} = ();

our $regex = '(?x: \b' .  join('\b | \b', map quotemeta, @words) . '\b )';

our (@regex, @map, @hash);

cmpthese( -100, {
	regex => q[ @regex = $string =~ m[($regex)]g; ],
	map  => q[ @map  = map{ my $var = quotemeta $_; $string =~ m[\b($var)\b] } @words; ],
	hash => q[ @hash = map{ exists $hash{$_} } split ' ', $string; ],
});

print scalar @regex, ':', scalar @map, ':', scalar @hash;
__END__
D:\Perl\test>temp
        Rate  map regex hash
map   31.5/s   -- -56%  -87%
regex 71.7/s 128%   --  -71%
hash   250/s 696% 249%    --
100:100:100

D:\Perl\test>temp
        Rate  regex   map  hash
regex 0.828/s    --  -62%  -97%
map   2.17/s   163%    --  -91%
hash  24.6/s  2871% 1031%    --
1000:1000:1000

D:\Perl\test>temp
            (warning: too few iterations for a reliable count)

            (warning: too few iterations for a reliable count)

     s/iter   regex    map   hash
regex   119     --    -71%  -100%
map     34.7   243%     --   -99%
hash   0.443 26705%  7715%     --
10000:10000:10000