#!/usr/bin/perl
use strict;
use warnings;

my $line = ('a' x 500) . ' ' . ('a' x 20);

use Benchmark qw( cmpthese );

cmpthese -2, {
    literal     => sub {$line =~ /a .{1,10} \ /x },
    class       => sub {$line =~ /a .{1,10} [ ]/x},
    class_nodot => sub {$line =~ /a [^\n]{1,10} [ ]/smx },
};
__END__
                Rate class_nodot       class     literal
class_nodot   2530/s          --        -26%       -100%
class         3413/s         35%          --       -100%
literal     718209/s      28289%      20942%          --