I've found scoping named subroutines useful when I want to initialize a data structure outside the subroutine but only visible to that one (or really as many as I want). 
...
{
    my @data = qw( this isn't visible elsewhere );
    sub func {
        # Do something with @data here
        ...
    }
}
...

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You could do just as well inside another subroutine instead of just a bare block (@data is private to both subroutines), then you're working with closures. Typically though the inner subroutine is spawned anonymously and returned from the outer sub. For a good example of that see List::MoreUtils's natatime.

Seeing as how others have pointed out the inner sub is not really purposefully scoped (you redeclare your variable with 'my'), I'm guessing at what you're asking about. Higher Order Perl is a good book and one that I've been meaning to finish which talks all about closures and other things you can do with higher order functions.

In reply to Re: Inner subroutines? by blakew
in thread Inner subroutines? by wsppan

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