use Perl

• Sub::Current for the Win! (Score:1)

  by Stevan (6065)

  See, this is exactly why I love Perl, cause there is always a something on CPAN that will make your life easier.

  use Sub::Current;
  
  print sub {
      my $num = shift;
      return $num < 2 ? 1 : $num * ROUTINE->($num - 1);
  }->(10);

  - Stevan
  • Re: (Score:2)

    by Ovid (2709)

    That's great, but solve my 'yield' problem and I'll really love you :)
    • Re: (Score:1)

      by Stevan (6065)

      I took the dog for a walk and thought about this a bit and realized where my scoping issue was. Here is a sugared version, probably could be a little cleaner still, maybe even with some subroutine attributes (sub foo : continuation { ... } or something).

      #!/usr/bin/perl
      
      use strict;
      use warnings;
      use Scalar::Util 'blessed';
      
      {
          package Foo;
          sub new { bless { val => $_[1] } => $_[0] }
          sub inc { $_[0]->{val} += $_[1] }
          sub val { shift->{val} }
      }
      
      our
      • yieldness (Score:1)

        by awwaiid (5634) <awwaiid@thelackthereof.org> on 2008.05.23 22:47 (#63015) Homepage Journal

        Ruby's use of the 'yield' keyword caught me off guard. I suppose I'm used to how python uses it, as part of generators (rather than as simply a sub invocation). Well... here's how you might do something similar with Coro::Generator anyway :)
        
        use strict;
        use Coro::Generator;
        
        {
          package Foo;
          sub new { bless { val => $_[1] } => $_[0] }
          sub inc { $_[0]->{val} += $_[1] }
          sub val { shift->{val} }
        }
        
        my $inner_testy = generator {
          my $foo = pop;
          foreach my $item (@_) {
            $foo->inc($item);
            yield($foo);
          }
          yield undef;
        };
        
        sub testy {
          my $action = pop;
          my $foo = Foo->new(1);
          $action->($foo) while $inner_testy->( @_, $foo );
        }
        
        testy(1,2,3, sub { print $_[0]->val . "\n" });
        

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