use strict;
use warnings;
use Benchmark qw(cmpthese);

my $klein = 'alpha - beta';

cmpthese (0, {
        m_klein => sub {
            my ($part) = $klein =~ m/^([^-]*)/;
        },
        split_klein => sub {
            my ($part) = split /-/,$klein,2;
        },
        mit_index => sub {
            my $part = substr($klein,0,index($klein, "-"));
        }
    });

my $gross = 'alpha - ' . 'beta' x 10000;

cmpthese (0, {
        m_gross => sub {
            my ($part) = $gross =~ m/^([^-]*)/;
        },
        split_gross => sub {
            my ($part) = split /-/,$gross,2;
        },
        mit_index => sub {
            my $part = substr($gross,0,index($gross, "-"));
        }
    });

        
                 Rate     m_klein split_klein   mit_index
m_klein      302083/s          --        -12%        -82%
split_klein  344837/s         14%          --        -79%
mit_index   1653727/s        447%        380%          --
                 Rate split_gross     m_gross   mit_index
split_gross   41553/s          --        -18%        -98%
m_gross       50924/s         23%          --        -97%
mit_index   1764431/s       4146%       3365%          --