Class::MakeMethods::ReadMe - About This Module


Class::MakeMethods::ReadMe - About This Module


  # Follow your standard download, test and install sequence
  perl -MCPAN -e 'install Class::MakeMethods'

  # Generates methods for your object when you "use" it.
  package MyObject;
  use Class::MakeMethods::Standard::Hash (
    'new'     => [ 'new' ],
    'scalar'  => [ 'foo', 'bar' ]

  # The resulting methods can be called exactly as normal ones
  package main;   
  my $obj = MyObject->new( foo => "Foozle", bar => "Bozzle" );
  print $obj->foo();


  "Make easy things easier."

This module addresses a problem encountered in object-oriented development wherein numerous methods are defined which differ only slightly from each other.

A common example is accessor methods for hash-based object attributes, which allow you to get and set the value $self->{'foo'} by calling a method $self->foo().

These methods are generally quite simple, requiring only a couple of lines of Perl, but in sufficient bulk, they can cut down on the maintainability of large classes.

Class::MakeMethods allows you to simply declare those methods to be of a predefined type, and it generates and installs the necessary methods in your package at compile-time.


The Class::MakeMethods framework allows Perl class developers to quickly define common types of methods. When a module uses a subclass of Class::MakeMethods, it can select from the supported method types, and specify a name for each method desired. The methods are dynamically generated and installed in the calling package.

Construction of the individual methods is handled by subclasses. This delegation approach allows for a wide variety of method-generation techniques to be supported, each by a different subclass. Subclasses can also be added to provide support for new types of methods.

Over a dozen subclasses are available, including implementations of a variety of different method-generation techniques. Each subclass generates several types of methods, with some supporting their own open-eneded extension syntax, for hundreds of possible combinations of method types.


Class::MakeMethods is based on Class::MethodMaker, but has been substantially revised in order to provide a range of new features. Although earlier versions of this module were posted for review as a possible ``version 2'' of MethodMaker, the maintainer of that module subsequently indicated that that he had different goals for future development and suggested a fork. (Full backward compatibility is provided by an emulator, described below.)

There are a variety of related modules on CPAN; I've included a quick review of several of these in the Class::MakeMethods::RelatedModules manpage. In comparison, this module aims to be quite general purpose and extensible while retaining acceptable performance characteristics.

Emulation Adaptors

In several cases, Class::MakeMethods provides functionality closely equivalent to that of an existing module, and it is simple to map the existing module's interface to that of Class::MakeMethods.

Class::MakeMethods::Emulator is available as a separate distribution from CPAN. See the Class::MakeMethods::Emulator manpage for more information. Emulators are included for Class::MethodMaker, Class::Accessor::Fast, Class::Data::Inheritable, Class::Singleton, and Class::Struct, each of which passes the original module's test suite, usually requiring only a single-line change.


You should be able to install this module using the CPAN shell interface:

  perl -MCPAN -e 'install Class::MakeMethods'

If this module has not yet been posted to your local CPAN mirror, you may also retrieve the current distribution from the below address and follow the normal ``gunzip'', ``tar xf'', ``cd'', ``perl Makefile.PL && make test && sudo make install'' procedure or your local equivalent:

Getting Started

If this is your first exposure to Class::MakeMethods, you may want to jump to the documentation for a few of the included subclasses, perhaps starting with the Class::MakeMethods::Standard::Hash manpage and the Class::MakeMethods::Standard::Universal manpage, before returning to the details presented below.


In general, this module should work with Perl 5.003 or later, without requring any modules beyond the core Perl distribution.

Certain features may be available only on some platforms, as noted below:

Tested Platforms

This release has been tested succesfully on the following platforms:

  5.6.1 on darwin

Earlier releases have also tested on the following platforms:

  5.005_02 on Rhapsody
  5.005_03 on sun4-solaris: PASS as of 1.0.13
  v5.6.0 on sun4-solaris: PASS as of 1.0.13
  v5.6.1 on WinNT: PASS as of 1.0.14.a (was TEST FAILURE as of 1.0.13)
  v5.6.? on RedHat 7.1 i386: TEST FAILURE as of 1.0.13
  v5.6.1 on ppc-linux-64all: FAIL as of 1.0.12
  5.004 on MacOS (MacPerl 520r4): PASS as of 1.0.6
  5.005 on WinNT (ActivePerl 618): PASS as of 1.0.6

You may also review the current test results from CPAN-Testers:;dist=Class-MakeMethods


This is version 1.004 of Class::MakeMethods.

Distribution Summary

This module's summary in the CPAN DSLIP is intended to read:

  Name            DSLIP  Description
  --------------  -----  ---------------------------------------------
  ::MakeMethods   bdpOp  Generate common types of methods

Beta Release

While numerous additional features have been outlined for future development, the intent is support these by adding more options to the declaration interface, while maintaining backward compatibility.

Discussion and Support

There is not currently any offical discussion and support forum for this pacakage.

If you have questions or feedback about this module, please feel free to contact the author at the below address.

I would be particularly interested in any suggestions towards improving the documentation, correcting any Perl-version or platform dependencies, as well as general feedback and suggested additions.


For an overview of this package, see the Class::MakeMethods manpage.

If you're just getting started, see the Class::MakeMethods::Standard manpage for a listing of common method generators.

If you need a bit more flexibility, see the Class::MakeMethods::Composite manpage for method generators which offer more customization options.

For the largest collection of methods and options, see the Class::MakeMethods::Template manpage, available as a separate distribution on CPAN.

If you have used Class::MethodMaker, you will note numerous similarities. Backward compatibility and conversion documentation is provded in the Class::MakeMethods::Emulator::MethodMaker manpage, available in a separate distribution on CPAN.


Developed By

  M. Simon Cavalletto,
  Evolution Softworks,

Source Material

Inspiration, cool tricks, and blocks of useful code for this module were extracted from the following CPAN modules:

  Class::MethodMaker, by Peter Seibel.
  Class::Accessor, by Michael G Schwern 
  Class::Contract, by Damian Conway
  Class::SelfMethods, by Toby Everett

Feedback and Suggestions

Thanks to:

  Martyn J. Pearce
  Scott R. Godin
  Ron Savage
  Jay Lawrence
  Adam Spiers
  Terrence Brannon


Copyright 2002 Matthew Simon Cavalletto.

Portions copyright 1998, 1999, 2000, 2001 Evolution Online Systems, Inc.

Portions copyright 1996 Organic Online.

Portions copyright 2000 Martyn J. Pearce.


You may use, modify, and distribute this software under the same terms as Perl.

 Class::MakeMethods::ReadMe - About This Module