Re: Let a module call a sub of the caller

[ikegami]

The same mechanisms pragmas use to clean themselves up can be used here. Here's an example:

call_when_scope_is_compiled.pm:

package call_when_scope_is_compiled;

use Sub::ScopeFinalizer qw( scope_finalizer );

sub import {
   my ($class, $sub) = @_;
   $^H{__PACKAGE__ . '::'} =
      scope_finalizer { $sub->() };
}

1;

$ perl -E'
   say "post";
   use call_when_scope_is_compiled \&foo;
   sub foo { say "foo!" }
   BEGIN { say "pre"; }
'
pre
foo!
post

It also works for narrower scopes.

$ perl -E'
   {
      use call_when_scope_is_compiled \&foo;
      sub foo { say "foo!" }
      BEGIN { say "pre"; }
   }
   BEGIN { say "post"; }
'
pre
foo!
post