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

my @var;
$var[0] = "Gallia est omnis divisa in partes tres";
$var[1] = "Gallia est omnis divisa in ...";
$var[2] = "Gallia est omnis ...";
$var[3] = "Gallia ...";
$var[4] = "... omnis divisa in ...";
$var[5] = "Gallia est ... tres";
$var[6] = "Gallia ... partes tres";
$var[7] = "Gallia est ... partes tres";
$var[8] = "Gallia ... divisa ... tres";
$var[9] = "... tres";
$var[10] = "quattuor";

for my $i (0 .. $#var) {
    for my $j ($i+1 .. $#var) {
        print "$i - $j DO NOT MATCH!\n" unless compare($var[$i], $var[$j]);
    }
}

sub compare {
    my @str1 = split /\Q...\E/, shift, -1;
    my @str2 = split /\Q...\E/, shift, -1;

    if (@str1 == 1) { # Regex is possible
        local $" = ".+";
        return $str1[0] =~ /^@str2$/;
    } elsif (@str2 == 1) {  # Regex is still possible
        local $" = ".+";
        return $str2[0] =~ /^@str1$/;
    } else { # Fragment matching
        # Openings must be consistent
        if (length $str1[0] > length $str2[0]) {
            return if index($str1[0], $str2[0]) != 0; 
        } else {
            return if index($str2[0], $str1[0]) != 0; 
        }
        
        # Closings must be consistent, start search from end
        if (length $str1[-1] > length $str2[-1]) {
            return if index(reverse($str1[-1]), reverse($str2[-1])) != 0; 
        } else {
            return if index(reverse($str2[-1]), reverse($str1[-1])) != 0; 
        }
    }
    
    return 1;
}