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These posts are the creation of Doran L. Barton (AKA Fozziliny Moo). To learn more about Doran, check out his website at

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Some cool Perl things...

Posted: 17 November 2010 at 15:36:43

One of the many advantages of having a software developer job where you're working in a distributed, collaborative development environment is that you get to look at other people's code. What a great way to see examples of coding strategies you've never used before.

For example, today I saw where someone had used the part subroutine provided by List::MoreUtils module. The part subroutine basically splits a list into two component parts: A part that meets the condition specified and the part that does not. The example given in the List::MoreUtils documentation is pretty decent:

my $i = 0;
my @part = part { $i++ % 2 } 1 .. 8;   

The contents of @part is now two elements, each a list reference to lists containing [1, 3, 5, 7] and [2, 4, 6, 8]. The first list contains elements from the original list (1 .. 8) that basically have a remainder after division by two. The second list contains elements which do not.

You can fetch each of the resulting list references into their own scalars:

my ($odd, $even) = part { $i++ % 2 } 1 .. 8; 

Now that I'm reading that code more closely, I think I like this variation, which drops the $i iterator and uses the input list instead, better:

my ($odd, $even) = part { $_ % 2 } 1 .. 8; 

Subroutines like part are very useful and many Perl developers make the mistake of throwing together their own implementation instead of looking to CPAN. If that describes you, stop it!