/ 
Object-Extend-0.0.1
River stage zero No dependents
/ Object::Extend

NAME

Object::Extend - add or override per-object methods

SYNOPSIS

use Object::Extend qw(extend);

my $foo1 = Foo->new;
my $foo2 = Foo->new;

extend $foo2 => {
    bar => sub { ... },
};

$foo1->bar; # error
$foo2->bar; # OK

DESCRIPTION

This module allows Ruby (and JavaScript) style "singleton methods" to be added to Perl objects. Singleton methods are added to an object-specific shim class (the object's eigenclass) which extends the object's original class. The original class is left unchanged.

For more details on singleton methods, see here: http://madebydna.com/all/code/2011/06/24/eigenclasses-demystified.html

EXPORT

extend

extend takes an object and a hash or hashref of method names and method values (coderefs) and adds the methods to the object's eigenclass. The object is then blessed into the eigenclass and returned.

It can be used in standalone statements:

extend $object, foo => sub { ... }, bar => \&bar;

Or expressions:

return extend($object => { bar => sub { ... } })->bar;

In both cases, extend operates on and returns the supplied object i.e. a new object is never created. If a new object is needed it can be handled manually e.g.:

my $object2 = Object->new($object1);
my $object3 = clone($object1);

extend($object2, foo => sub { ... })->foo;
return extend($object3 => ...);

Objects can be extended multiple times with the same or different methods:

my $object = Foo->new;

# call the original method
$object->foo;

# override the original method
extend $object => foo => sub { ... };
$object->foo;

# add a new method
extend $object => bar => sub { ... };
$object->bar;

with

This sub can optionally be imported to make the use of extend more descriptive. It takes and returns a hashref of method names/coderefs:

use Object::Extend qw(extend with);

extend $object => with { foo => sub { ... } };

METHODS

EIGENCLASS

Every extended object's eigenclass includes an additional class in its @ISA which indicates that the object has been extended. This class name is accessible via the EIGENCLASS method e.g.:

if ($object->isa(Object::Extend->EIGENCLASS)) { ... } # object extended with object-specific methods

VERSION

0.0.1

SEE ALSO

AUTHOR

chocolateboy <chocolate@cpan.org>

COPYRIGHT AND LICENSE

Copyright (C) 2013 by chocolateboy

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.14.2 or, at your option, any later version of Perl 5 you may have available.