in reply to Re^2: Closures and undefined subs
in thread Closures and undefined subs

Just to make it more clear:
Status quo: 

use Math::RungeKutta;

sub outer {
   my $var = sub_from_other_package();
   no warnings qw(closure);

   sub differ {
      my $y = shift;
      $var->[...]{...}{...}; etc.
      ...
      return $res;
   }

   sub dydt {
      my ($t,@y) = @_;
      return differ($y);
   };

   ($t, @y) = rkXXX(\@y, \&dydt, $t, $dt);

}

[download]
Neither local nor subs declared in lexicals help me out of my misery. The former is undefined the next is used as ""-ref. So There is a bug but what could it be that turns a sub into undefined?
Hope you still with me and not bored ;)

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Re^4: Closures and undefined subs
by ikegami (Patriarch) on Sep 26, 2007 at 16:13 UTC 
    use Math::RungeKutta;

sub outer {
   my $var = sub_from_other_package();

   my $differ = sub {
      my $y = shift;
      $var->[...]{...}{...}; etc.
      ...
      return $res;
   };

   my $dydt = sub {
      my ($t,@y) = @_;
      return $differ->($y);
   };

   ($t, @y) = rkXXX(\@y, $dydt, $t, $dt);  
}

    [download]
    • Removed no warnings qw(closure);.
    • Converted each named sub to an anon sub.
      • Don't forget the semi-colon at the end of the block. sub is like a function when there's no name.
    • Changed \&dydt.
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[d/l]
[select]
      Will try it out tomorrow. Original code of the whole module (but it needs other 3 not posted and the original main programme) was posted as answer for your demand for original code a bit earlier.
[reply]

        I didn't ask for the original code. Quite the opposite. I asked for the code giving the error. What you posted doesn't demonstrate the problem, so its useless. We can't debug code we don't see.

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