NAME Object::Util - a selection of utility methods that can be called on blessed objects SYNOPSIS use Object::Util; # $foo might be undef, but this should not die if ($foo->$_isa("Bar")) { ...; } DESCRIPTION This module is inspired by Safe::Isa, Object::Tap, and my own OO experiences. It is a hopefully helpful set of methods for working with objects, exposed as lexical coderef variables. Rationale Providing methods as coderefs so that you can do: $object->$_foo(@args) ... is unusual, so probably requires some explanation. Firstly some of these methods are designed to be called on either a blessed object or some kind of unblessed reference or value. Calling a method on an unblessed reference like this will croak: $ref->foo(@args) Ditto calling methods on undef. Coderefs don't suffer from that problem. More importantly though, the aim of this module is that these methods should be available for you to call on *any* object. You can only call `$object->foo(@args)` if $object's class implements a method called `foo`, or inherits from a superclass that does. Coderef methods can be called on any object. This module adopts the $_foo naming convention pioneered by modules such as Safe::Isa. However (unlike Safe::Isa) the coderefs it provides are *true lexical variables* (a.k.a. `my` variables), not package variables (a.k.a. `our` variables). Methods $_new Can be used as `$factory->$_new(@args)` to create a new object. $factory may be a class name (the module will be auto-loaded), or may be a coderef or object overloading `&{}`. If it's a class name, then `$class->new(@args)` will be called; otherwise `$coderef->(@args)` will be called. $_isa `$object->$_isa($class)` works like `isa` as defined in UNIVERSAL, but returns `undef` if $object is undefined. Same as Safe::Isa. $_can `$object->$_can($class)` works like `can` as defined in UNIVERSAL, but returns `undef` if $object is undefined. Same as Safe::Isa. $_does `$object->$_does($class)` works like `does` as defined in Moose::Object, but returns `undef` if $object is undefined. Same as Safe::Isa. $_DOES `$object->$_DOES($class)` works like `DOES` as defined in UNIVERSAL, but returns `undef` if $object is undefined. Same as Safe::Isa. $_call_if_object `$object->$_call_if_object($method => @args)` works like `$object->$method(@args)`, but returns `undef` if $object is undefined. Same as Safe::Isa. $_try `$object->$_try($method => @args)` works like `$object->$method(@args)`, but returns `undef` if any exception is thrown. $_tap `$object->$_tap($method => @args)` works like `$object->$method(@args)`, but returns the object itself, making it useful for chaining. Same as Object::Tap, or the `tap` method in Ruby. $_clone If the object provides a `clone` method, calls that. Or if the object appears to be Moose- or Mouse-based, clones it using the metaobject protocol. Otherwise takes the naive approach of treating the object as a hashref or attribute values, and creates a new object of the same class. # clone overrides some attributes from the original object my $glenda = $glen->$_clone(name => "Glenda", gender => "f"); That final fallback obviously massively breaks your class' encapsulation, so it should be used sparingly. $_with_traits Calling `$class->$_with_traits(@traits)` will return a new class name that does some extra traits. Should roughly support Moose, Moo, and `Role::Tiny`. $_dump Calling `$object->$_dump` returns a Data::Dumper dump of the object, with some useful changes to the default Data::Dumper output. (Same as Data::Dumper::Concise.) Implementation Details B::Hooks::Parser is used to inject these methods into your lexical scope, and `Internals::SvREADONLY` (an internal function built into the Perl core) is used to make them read-only, so you can't do: use Object::Util; $_isa = sub { "something else" }; If this module detects that B::Hooks::Parser cannot be used on your version of Perl, or your Perl is too old to have Internals::SvREADONLY, then it has various fallback routes, but the variables it provides may end up as package (`our`) variables, or not be read-only. BUGS Please report any bugs to . SEE ALSO Safe::Isa, UNIVERSAL, Object::Tap, MooseX::Clone, Data::Dumper::Concise. AUTHOR Toby Inkster . COPYRIGHT AND LICENCE This software is copyright (c) 2014 by Toby Inkster. This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself. DISCLAIMER OF WARRANTIES THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.