y-combinator.pl

y-combinator.pl

#!/usr/bin/env perl
use strict;
use warnings;

sub y_combinator (&) {
    my $curried = shift;
    return sub {
        my $f1 = shift;
        return $curried->(sub { $f1->($f1)(@_) });
    }->(sub {
        my $f2 = shift;
        return $curried->(sub { $f2->($f2)(@_) });
    });
}

my @numbers = (1,2,3);
y_combinator {
    my $recurse = shift;
    return sub {
        my $number = shift @numbers;
        warn "number: $number\n";
        return scalar @numbers ? $recurse->() : undef;
    };
}->();

My big references for y-combinators are:

http://stackoverflow.com/questions/93526/what-is-a-y-combinator

and two of the linked articles:
http://mvanier.livejournal.com/2897.html
http://www.mail-archive.com/[email protected]/msg02716.html