While writing this (shameless plug), i came up with a (almost) one-line way of removing duplicates from an ever-expanding array and sorting the remaining values. Unfortunately i have two problems:

1) Me thinks this isn't the best way to do it (i really don't want to create two hashes)
2) i don't understand completely why it works.

So, if monks with better knowledge of grep could please help me out here, i would much appreciate it. 



sub beautify {
   my (%old, %new);
   return sort { $a <=> $b }
   grep {
          $new{$_}++;
          $old{$_}++ unless exists $old{$_};
          my $ret = $new{$_}==$old{$_} ?
                    1 :
                    $new{$_}+1==$old{$_} ? 1 : 0;
          $old{$_} = $new{$_};
          $ret;
       } @_;
}

[download]
This gets as called as @array = beautify(@array, $new_value, $new2);

What i want to know is, why doesn't grep just return all values as being ok (since it looks like $old{$_} will always be within 1 of $new{$_})?

And what better ways are there to do this (in one line)?

Please help,
jynx

In reply to quandery about a grep statement by jynx

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