use strict;
use warnings;
use Benchmark qw/timethese/;

# Test/Benchmark parameters.
$main::string = q/CTTCGAATT/;
our $time = 10000000;

my $subs_to_test = {
    substr  => \&by_substr,
    match   => \&by_match,
    unpack  => \&by_unpack,
    control => \&control,
};


# Benchmark.
timethese( $time, $subs_to_test );

# Subs being benchmarked.
sub control {
    my @substrings;
    @substrings = qw/CTT CGA ATT/;
    return \@substrings;
}

sub by_substr {
    my $position = 0;
    my @substrings;
    while( $position < length $main::string ) {
        push @substrings, substr( $main::string, $position, 3 );
        $position += 3;
    }
    return \@substrings;
}

sub by_match {
    my @substrings;
    while( $main::string =~ m/(...)/sg ) {
        push @substrings, $1;
    }
    return \@substrings;
}

sub by_unpack {
    my @substrings;
    @substrings = unpack( '(a3)*', $main::string );
    return \@substrings;
}