in reply to Re: Re: autoload and packages
in thread AUTOLOAD and packages

okay, you decided not to do exercise for a reader :)
Let me give you my code for example for a reader: 
BEGIN{
  if (exists $::{AUTOLOAD}) {
    print "exisa\n";
  } else {
    print "no-exisa\n";
  }
}
sub AUTOLOAD{}
BEGIN{
  if (exists $::{AUTOLOAD}) {
    print "exisa\n";
  } else {
    print "no-exisa\n";
  }
}

[download]
Sorry for not clearing it for cleverness, I'm drunk now :)
but I checked it, it works!

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Re: Re: Re: Re: autoload and packages
by smackdab (Pilgrim) on May 12, 2002 at 01:22 UTC
    Thanks Svad ---remember, friends don't let friends code drunk :*)

    I'll post the entire module later, as I guess I can't explain what I am trying to do...unfortunately this is normal as I am learning perl by trial and error...

    I know that I can check to see if main::AUTOLOAD is defined and I guess I could die() if it is...I just was wondering if I could save the function pointer and insert mine in its place. Then I would call the original one and no one would be the wiser ;-)

    I want to create a module that you can just "use" and it would take care of "fixing" any AUTOLOAD requirements.

    Of course if I wanted to not have a dynamic function name none of this would be an issue...but what fun is that !

[reply]
      if we'll see into perlref.pod and search for substring {CODE} and read around a bit, then we'll calmly understand that we're able to do following trick: 
      use strict;

package main;

sub AUTOLOAD {
  return 'old-main-autoload';
}

package mypackage;

# let's capture that ::AUTOLOAD
my $aasub = *{$::{AUTOLOAD}}{CODE};

# now let's, as we decided earlier, have it overloaded
*::AUTOLOAD = sub {
  # here how we overload it:
  print "do first\n";
  #call old one and print that returned value inside '[]'
  print '[', $aasub->(), "]\n";
  print "do last\n";
};

package main; # again

flurfish_sub();

      [download]
      in my case output is 
      do first
[old-main-autoload]
do last

      [download]
      But my personal advice - you're moving to C-like area or even assembler code catching area when you will really soon will complicate logic.
      I think when you will see that code in your program then it is a good signal to redesign your code.
      :)

      Best wishes,
      Vadim.

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