#!/usr/bin/perl

use Benchmark 'cmpthese';

my $X = "a b c d e f g h i j k l ";
my $Y = "a b c d e f g h i j k l";

cmpthese(-5, {
  P_while => sub {
    my $x = $X;
    1 while $x =~ s/\s$//;
  },
  P_plus => sub {
    my $x = $X;
    $x =~ s/\s+$//;
  },
  P_sexeger => sub {
    my $x = reverse $X;
    $x =~ s/^\s+//;
    $x = reverse $x;
  },

  F_while => sub {
    my $x = $Y;
    1 while $x =~ s/\s$//;
  },
  F_plus => sub {
    my $x = $Y;
    $x =~ s/\s+$//;
  },
  F_sexeger => sub {
    my $x = reverse $Y;
    $x =~ s/^\s+//;
    $x = reverse $x;
  },
});