Hello,

I have an a situation where I have multiple levels of derived objects that all need to implement the same method (in my simplified case below, I have named it 'do_something'). Each package knows how to 'do_something' with the data that it cares about, and it needs to recursively tell its parent in the inheritance tree to do_something with the data as well. For simplicity sake, assume that each class only inherits from one class (no multiple inheritance).

After I got started coding all of the do_something's, I found the code was so similar in each case, that it would be a crime not to just write it once and re-use the code. I thought I could do this via closures. But being a newbie to closures, I appear to be doing something wrong.

Here is the model I'm trying to implement:

#file: Foo.pm
package Foo;

*do_something = &make_do_something( 'foo' );

sub make_do_something {
    my $name = shift;
    ## In my real code, I have other interesting params here
    ## that gives my sub the information to do the
    ## things that each class knows about.
    return sub { 
        my $self = shift;
        if ( $name ne 'foo' ) {
            print "Not foo\n";
            $self->SUPER::do_something();
        }
        print "Foo $name!!!\n";
        return 1;
    }
}
__END__

#File: Bar.pm
package Bar;

use base 'Foo';

*do_something = &Foo::make_do_something( 'bar' );

sub new { 
    bless {}, shift();
}
__END__

#!/usr/local/bin/perl
#File: foobar.pl

use Foo;
use Bar;

$b = new Bar();

$b->do_something();
__END__

[download]

Now, I was hoping that I would see something like this:

Not foo
Foo foo!!!
Foo bar!!!
Regretfully, I'm getting this:
Not foo
Can't locate object method "do_something" via package "Foo"
 (perhaps you forgot to load "Foo"?) at Foo.pm line 13.
Is it possible to do what I'm trying to do here? What am I doing wrong?

In reply to Trying to re-use code at different levels of an inherited object. by ehdonhon

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