Playing with pugs I decided to tackle combinations in a perl6-ish way if i could manage. So I took the binary counting method and applied it. I think the results worked out pretty well but i'm still left betting there is an easier method. What do you think? What could be done different? SVN Version of the code 

sub combinations returns Array  (@list is rw) {
  return () unless @list.elems;
  my @ans;
  for 1 .. 2**@list.elems-1-> $num {
      push @ans, [ @list[ (0 .. sqrt($num)).grep:{ $num +& (2**$_) } ]
+ ];
  }
  return @ans;
} 
my @list = (1..4);
combinations(@list).perl.say;
__OUTPUT__
([1], [2], [1, 2], [3], [1, 3], [2, 3], [1, 2, 3], [4], [1, 4], [2, 4]
+, [1, 2, 4], [3, 4], [1, 3, 4], [2, 3, 4], [1, 2, 3, 4])

[download]

___________
Eric Hodges

In reply to P6: Combinations Solution by eric256

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.