#!/usr/bin/env perl -l

use strict;
use warnings;

use Benchmark qw{cmpthese};

my @strings = (
    'A B C', 'D E', 'F ', 'G', 'H  ', 'I   ',
    "\N{MERCURY} \N{FEMALE SIGN} \N{EARTH}", "\N{MALE SIGN} \N{JUPITER}",
    "\N{SATURN} ", "\N{URANUS}", "\N{NEPTUNE}  ", "\N{PLUTO}   ",
);

my $re = qr{\s+\b};

cmpthese -1 => {
    no_re_check_and_split => \&no_re_check_and_split,
    re_check_and_split => \&re_check_and_split,
    split_and_re_check => \&split_and_re_check,
};

sub no_re_check_and_split {
    for (@strings) {
        next if substr($_, -1, 1) eq ' ' or rindex($_, ' ', length() - 2) == -1;
        my @parts = split /$re/;
    }
}

sub re_check_and_split {
    for (@strings) {
        next unless /$re/;
        my @parts = split /$re/;
    }
}

sub split_and_re_check {
    for (@strings) {
        my @parts = split /$re/;
        next if @parts > 1;
    }
}