Beefy Boxes and Bandwidth Generously Provided by pair Networks
Just another Perl shrine
 
PerlMonks  

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??
tilly once posted something that could be coerced to do this.

Update: It would be kind of the inside-out solution to this problem, you could get a function callback for every combination of values, but I think to get an actual iterator function using this method, similar to the iterator produced by my $iter = do { my $i; sub { $i++ } };, you'd need a co-routine. Unless tilly can wrangle it out of his code :-)

There does seem to be a Coroutine Module on CPAN, might be fun to look into :)

Update: Taking the initiative, I wrangled tilly's code myself (just couldn't wait for the book :)

use strict; use warnings; my $iterator = mk_iter( [1..2], ["a".."c"], [3..5] ); while (my @arr = $iterator->()) { print "@arr\n"; } sub mk_iter { my $range = shift; my $i = 0; my $end = @$range; my $iter = sub { return unless $i < $end; return $$range[$i++]; }; @_ ? ret_iter($iter, @_) : $iter; } sub ret_iter { my $iter = shift; my $range = shift; my $i = 0; my $end = @$range; my @arr; my $new_iter = sub { $i = 0 unless $i < $end; return unless $i or @arr = $iter->(); return @arr, $$range[$i++]; }; @_ ? ret_iter($new_iter, @_) : $new_iter; } ##################################### # Update # Here's a variation which is closer to what was # Originally asked for, i.e. all combinations from # 2-4 characters use strict; use warnings; use strict; use warnings; my $iterator = make_iter( 2,4,[qw(A C G N T)] ); while (my @arr = $iterator->()) { print "@arr\n"; } sub make_iter { my ($start, $end, $range) = @_; my $nxt_iter = sub { return }; my $iter = sub { my @data; unless (@data = $nxt_iter->()) { return unless $start <= $end; $nxt_iter = mk_iter( ($range) x $start++); return $nxt_iter->(); }; @data; } }

In reply to Re: Let's get lazy by runrig
in thread Let's get lazy by guillaume

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!
  • 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, 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, 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.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others romping around the Monastery: (19)
    As of 2015-07-31 16:31 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      The top three priorities of my open tasks are (in descending order of likelihood to be worked on) ...









      Results (279 votes), past polls