Writing a bubble sort using Perl regular expressions - regex

Question

I'm beginning to learn perl and I'm writing a simple bubble sort using regular expressions. However, I can't get it to sort properly (alphabetically, delimiting by whitespace). It just ends up returning the same string. Can someone help? I'm sure it's something really simple. Thanks:
#!/usr/bin/perl
use warnings;
use strict;
my $document=<<EOF;
This is the beginning of my text...#more text here;
EOF
my $continue = 1;
my $swaps = 0;
my $currentWordNumber = 0;
while($continue)
{
$document =~ m#^(\w+\s+){$currentWordNumber}#g;
if($document =~ m#\G(\w+)(\s+)(\w+)#)
{
if($3 lt $1)
{
$document =~ s#\G(\w+)(\s+)(\w+)#$3$2$1#;
$swaps++;
}
else
{
pos($document) = 0;
}
$currentWordNumber++;
}
else
{
$continue = 0 if ($swaps == 0);
$swaps = 0;
$currentWordNumber = 0;
}
}
print $document;
SOLVED: I figured out the problem. I wasn't taking into account punctuation after a word.

Answer 1

If you just want to sort all the words, you don't have to use regular expressions... Simply splitting up the text by newlines and white spaces should be much faster:
sub bsort {
my #x = #_;
for my $i (0..$#x) {
for my $j (0..$i) {
#x[$i, $j] = #x[$j, $i] if $x[$i] lt $x[$j];
}
}
return #x;
}
print join (" ", bsort(split(/\s+/, $document)));