Re: How to return a list using recursion?

[tobyink]

I agree that this isn't necessarily the best task to use recursion for, but here's one possibility:

use Data::Dumper;

sub mk_chunker
{
    my $n = shift;
    die unless $n > 0;
    my $sub;
    return $sub = sub {
        return \@_ if @_ < $n;
        return (
            [ @_[0..$n-1] ],
            $sub->(@_[$n..$#_]), # recursion
        );
    };
}

*chunk_5 = mk_chunker(5);

print Dumper chunk_5('a' .. 'z');

The closure in mk_chunker is a good candidate for Perl 5.16's new __SUB__ feature...

use 5.016;

sub mk_chunker
{
    my $n = shift;
    die unless $n > 0;
    return sub {
        return \@_ if @_ < $n;
        return (
            [ @_[0..$n-1] ],
            __SUB__->(@_[$n..$#_]), # recursion
        );
    };
}