I've been going over the posts and tutorials here on this subject, and I have made it to the point where I can code a very straightforward example of very simple recursion.

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

sub recurse_factory {
  my $max = shift;
  my $number = shift;
  if ($number < $max) {
    return sub { return recurse_factory($max,$number+1); }
  } else {
    return sub { print "done ... $number\n"; };
  }
}

my $TIMES = 100;
my $next = recurse_factory(100,0);
for (1..$TIMES+1) {
  $next = $next->();
}
[download]

However, I am trying to figure out how one may use this method (if at all) for a more complicated recursive algorithm. In essence what I'd like to do is find all acyclic paths in a digraph using the recursive depth first search method.

In otherwords, the recursion pattern looks more like the depth first traversal of a tree than a simple straight line like my simple example above. I am sure locked away in the great explanations I've found on this site is the key, but I need to be hit with a really big clue stick.

I think for this discussion, the recursive depth first traversal of a tree that returns a full root-to-leaf path would be an appropriate example...btw, I am assuming that this can be done with rgi's, but I could be wrong there, too.

TIA