use strict;
use Benchmark qw/ cmpthese /;

our $a = "abcdefghij" x 1000;
cmpthese(-1, {
  l3epost => q{ my %a; $a{$1}++ while $a =~ /(?=(.{3}))/g },
  l3epre  => q{ my %a; ++$a{$1} while $a =~ /(?=(.{3}))/g },
  l3ipost => q{ my %a; $a{$1}++ while $a =~ /(?=(...))/g },
  l3ipre  => q{ my %a; ++$a{$1} while $a =~ /(?=(...))/g },
});