private - Add private data members to Perl classes

  package GI::Joe;

  use private qw( _SexualPrefs _IsSpy );

  # see the protected man page for an example

Private member.

Internal data or functionality. An attribute or method only directly accessible to the methods of the same class and inaccessible from any other scope. In Perl, notionally private attributes and members are conventionally given names beginning with an underscore.

From "Object Oriented Perl" by Damian Conway

private.pm adds a list of keys as private data members to the current class. See public for more info.

Private data members are those pieces of data which are expected to be only accessed by methods of the class which owns them. They are not inherited by subclasses.

private.pm serves a subset of the functionality of fields.pm.

  use private qw(_Foo);

is almost exactly the same as:

  use fields qw(_Foo);

with the exception that you can (if you REALLY want to) do something like this:

  use private qw(Foo);

Whereas one cannot do this with fields.pm. (Note: This is considered unwise and private.pm will scream about it if you have Perl's warnings on.)

Additionally, private.pm is a bit clearer in its intent and is not necessarily implying use of pseudo-hashes.

See SYNOPSIS in protected for an example of use.

I fully expect private.pm to eventually mutate into a real pragma someday when a better formalized OO data system for Perl supplants the current fledgling pseudo-hashes.

Michae G Schwern <schwern@pobox.com>

public, protected, fields, base, Class::Fields