#!/usr/bin/env perl
use Modern::Perl;
use Benchmark qw(:all);

# create a line with words and spaces to split on
my $line = '';
$line .= ('a', 'b', 'c', 'd', ' ')[rand(5)] for (1..1000);

cmpthese( 100000, {
		'loop with vars' => \&loopwithvars,
		'loop sans vars' => \&loopsansvars,
		'with map'       => \&withmap,
});

sub loopwithvars {
	my %wordcount;
	my @words = split ' ', $line;
	for my $word (@words){
		$wordcount{$word}++;
	}
}
sub loopsansvars {
	my %wordcount;
	for (split ' ', $line){
		$wordcount{$_}++;
	}
}

sub withmap {
	my %wordcount;
	map { $wordcount{$_}++ } split ' ', $line;
}

###### results ######
                  Rate loop with vars       with map loop sans vars
loop with vars 11338/s             --           -15%           -17%
with map       13369/s            18%             --            -2%
loop sans vars 13624/s            20%             2%             --