use Perl

• sort with code ref (Score:2)

  by bart (450)

  It would really help if sort would take a subroutine reference but it doesn't it takes a block or a subroutine name. Grump.

  Thankfully, you're wrong. sort is happy to take a code ref.

  @x = 1 .. 20;
  $bynumdesc = sub { return $b <=> $a };
  $\ = "\n";
  print for sort $bynumdesc @x;

  That definitely would appear to work, correctly printing the numbers from 1 to 20 in reversed order, on any perl I throw it at, from 5.6.1 to 5.10.0.
  • Re:sort with code ref (Score:2)

    by drhyde (1683) on 2008.07.25 7:16 (#64036) Homepage Journal

    Hmmm, interesting. It takes a coderef if that coderef is stored in a variable, but not just a plain old code-ref, or one returned directly from a function. I suppose it's not entirely unreasonable for the parser to get a bit confused in that case.

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    • Re: (Score:1)

      by Aristotle (5147)

      Yeah, the sort function has a bunch of terrible, horrible, awful special cases in place that are supposed to DWIM but end up surprising me much of the time I use sort otherwise than by passing an explicit, inline comparator block.