NAME

Callback::Cleanup - Declare callbacks that clean themselves up

SYNOPSIS

        use Callback::Cleanup;

        my $anon_sub = callback {
                # this is the sub body
        } cleanup {
                # this is called on DESTROY
        }

        # or

        Callback::Cleanup->new(
                sub { }, # callback
                sub { }, # cleanup
        );

DESCRIPTION

This is a very simple module that provides syntactic sugar for callbacks that need to finalize somehow.

Callbacks are very convenient APIs when they have no definite end of life. If an end of life behavior is required this helps keep the cleanup code and callback code together.

EXPORTS

callback BLOCK $cleanup

cleanup BLOCK $callback

Both of these exports act as the identity function when given only one parameter.

When given enough arguments they will create a Callback::Cleanup object.

This means that you can declare a callback with a cleanup like this:

        my $cleans_up = callback {

        } cleanup {
        
        }

Or a derived sub that cleans up an existing subref:

        my $cleans_up = cleanup {

        } \&needs_cleanup;

As well as a few other useless forms.

CLOSURES AND GARBAGE COLLECTION

In perl code references that are not closures aren't garbage collected (they are shared).

This module uses "clone_if_immortal" in Sub::Clone to make sure timely destruction of these callbacks happens.

AUTHOR

Yuval Kogman <nothingmuch@woobling.org>

COPYRIGHT & LICENSE

        Copyright (c) 2006, 2008 the aforementioned authors. All rights
        reserved. This program is free software; you can redistribute
        it and/or modify it under the same terms as Perl itself.