Object-InsideOut version 1.04.00
================================

This module provides comprehensive support for implementing classes using the
inside-out object model.

This module implements inside-out objects as anonymous scalar references that
are blessed into a class with the scalar containing the ID for the object
(usually a sequence number).  Object data (i.e., fields) are stored within the
class's package in either arrays indexed by the object's ID, or hashes keyed
to the object's ID.

The virtues of the inside-out object model over the 'blessed hash' object
model have been extolled in detail elsewhere.  Briefly, inside-out objects
offer the following advantages over 'blessed hash' objects:

= Encapsulation

Object data is enclosed within the class's code and is accessible only through
the class-defined interface.

= Field Name Collision Avoidance

Inheritance using 'blessed hash' classes can lead to conflicts if any classes
use the same name for a field (i.e., hash key).  Inside-out objects are immune
to this problem because object data is stored inside each class's package, and
not in the object itself.

= Compile-time Name Checking

A common error with 'blessed hash' classes is the misspelling of field names:

    $obj->{'coment'} = 'No comment';   # Should be 'comment' not 'coment'

As there is no compile-time checking on hash keys, such errors do not usually
manifest themselves until runtime.

With inside-out objects, data is accessed using methods, the names of which
are checked by the Perl compiler such that any typos are easily caught using
"perl -c".


This module offers all the capabilities of Class::Std with the following
additional key advantages:

= Speed

When using arrays for storing object data, Object::InsideOut objects are as
much as 40% faster than 'blessed hash' objects for fetching and setting data,
and even with hashes they are still several percent faster than 'blessed hash'
objects.

For the same types of operations, Object::InsideOut objects are from 2 to 6
times faster than Class::Std objects.

= Threads

Object::InsideOut is thread safe, and thoroughly supports sharing objects
between threads using threads::shared.  Class::Std is not usable in threaded
applications (or applications that use 'fork' under ActiverPerl).

= Flexibility

Allows control over object ID specification, accessor naming, parameter name
matching, and more.

= mod_perl and Runtime Loading

Usable from within mod_perl, and supports classes that may be loaded at
runtime (i.e., using "eval { require ...; };").

= Perl 5.6

Usable with Perl 5.6.0 and later.  Class::Std is only usable with Perl 5.8.1
and later.

= Exception Objects

As recommended in "Perl Best Practices", Object::InsideOut uses
Exception::Class for handling errors in an OO-compatible manner.

= Object Serialization

Object::InsideOut has built-in support for object dumping and reloading that
can be accomplished in either an automated fashion or through the use of
class-supplied subroutines.

INSTALLATION

To install this module type the following:

    perl Makefile.PL
    make
    make test
    make install

or if you have Module::Build installed:

    perl Build.PL
    perl Build
    perl Build test
    perl Build install

DEPENDENCIES

Requires Perl 5.6.0 or later.

This module uses the following 'standard' modules:

  ExtUtils::MakeMaker          - For installation
  Test::More (0.50 or later)   - For installation
  Scalar::Util (1.10 or later) - Standard in 5.8 or obtain from CPAN

This module requires the following module available from CPAN:

  Exception::Class (1.22 or later)

COPYRIGHT AND LICENCE

Copyright 2005 Jerry D. Hedden <jdhedden AT 1979 DOT usna DOT com>

This program is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.

# EOF