blokhead,
I doubt this is how tye would have implemented it, but this is 1 implementation of his 3 simple rules: 
#!/usr/bin/perl
use strict;
use warnings;

my $next = iter_powerset( 1,2,3,4,5 );
while ( my @combo = $next->() ) {
    print "@combo\n";
}

sub iter_powerset {
    my @factor = @_;
    my $end = $#factor;
    my @subset = (undef) x $end;
    my ($pos, $mode) = (-1, 1);
    my $return = sub { return @factor[ grep defined, @subset ] };
    my %dispatch = (
        1 => sub {
            ++$pos;
            $subset[ $pos ] = $pos;
            ++$mode if $pos == $end;
            $return->();
        },
        2 => sub {
            $subset[ $pos - 1 ] = undef;
            ++$mode;
            $return->();
        },
        3 => sub {
            $subset[ $pos-- ] = undef;
            while ( $pos >= 0 ) {
                last if defined $subset[ $pos ];
                --$pos;
            }
            $subset[ $pos++ ] = undef;
            return () if ! $pos;
            $subset[ $pos ] = $pos;
            $mode = 1;
            $return->();
        },
    );
    return sub { $dispatch{ $mode }->() };
}

[download]
I am now going to play with making it closer to what I want for the other task.

Cheers - L~R

Since tye's 3 simple rules were uttered in passing on the CB, I will summarize them here to help explain the code

In reply to Re^2: Generating powerset with progressive ordering by Limbic~Region
in thread Generating powerset with progressive ordering by Limbic~Region

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.