tie::refhash(3pm) [suse man page]

Tie::RefHash(3pm)					 Perl Programmers Reference Guide					 Tie::RefHash(3pm)

NAME

       Tie::RefHash - use references as hash keys

SYNOPSIS

	   require 5.004;
	   use Tie::RefHash;
	   tie HASHVARIABLE, 'Tie::RefHash', LIST;
	   tie HASHVARIABLE, 'Tie::RefHash::Nestable', LIST;

	   untie HASHVARIABLE;

DESCRIPTION

       This module provides the ability to use references as hash keys if you first "tie" the hash variable to this module.  Normally, only the
       keys of the tied hash itself are preserved as references; to use references as keys in hashes-of-hashes, use Tie::RefHash::Nestable,
       included as part of Tie::RefHash.

       It is implemented using the standard perl TIEHASH interface.  Please see the "tie" entry in perlfunc(1) and perltie(1) for more
       information.

       The Nestable version works by looking for hash references being stored and converting them to tied hashes so that they too can have
       references as keys.  This will happen without warning whenever you store a reference to one of your own hashes in the tied hash.

EXAMPLE

	   use Tie::RefHash;
	   tie %h, 'Tie::RefHash';
	   $a = [];
	   $b = {};
	   $c = *main;
	   $d = "gunk";
	   $e = sub { 'foo' };
	   %h = ($a => 1, $b => 2, $c => 3, $d => 4, $e => 5);
	   $a->[0] = 'foo';
	   $b->{foo} = 'bar';
	   for (keys %h) {
	      print ref($_), "
";
	   }

	   tie %h, 'Tie::RefHash::Nestable';
	   $h{$a}->{$b} = 1;
	   for (keys %h, keys %{$h{$a}}) {
	      print ref($_), "
";
	   }

THREAD SUPPORT

       Tie::RefHash fully supports threading using the "CLONE" method.

STORABLE SUPPORT

       Storable hooks are provided for semantically correct serialization and cloning of tied refhashes.

RELIC SUPPORT

       This version of Tie::RefHash seems to no longer work with 5.004. This has not been throughly investigated. Patches welcome ;-)

MAINTAINER

       Yuval Kogman <nothingmuch@woobling.org>

AUTHOR

       Gurusamy Sarathy        gsar@activestate.com

       'Nestable' by Ed Avis   ed@membled.com

SEE ALSO

       perl(1), perlfunc(1), perltie(1)

perl v5.12.1							    2010-04-26							 Tie::RefHash(3pm)

Tie::Scalar(3pm)					 Perl Programmers Reference Guide					  Tie::Scalar(3pm)

NAME

       Tie::Scalar, Tie::StdScalar - base class definitions for tied scalars

SYNOPSIS

	   package NewScalar;
	   require Tie::Scalar;

	   @ISA = qw(Tie::Scalar);

	   sub FETCH { ... }	       # Provide a needed method
	   sub TIESCALAR { ... }       # Overrides inherited method

	   package NewStdScalar;
	   require Tie::Scalar;

	   @ISA = qw(Tie::StdScalar);

	   # All methods provided by default, so define only what needs be overridden
	   sub FETCH { ... }

	   package main;

	   tie $new_scalar, 'NewScalar';
	   tie $new_std_scalar, 'NewStdScalar';

DESCRIPTION

       This module provides some skeletal methods for scalar-tying classes. See perltie for a list of the functions required in tying a scalar to
       a package. The basic Tie::Scalar package provides a "new" method, as well as methods "TIESCALAR", "FETCH" and "STORE". The Tie::StdScalar
       package provides all the methods specified in  perltie. It inherits from Tie::Scalar and causes scalars tied to it to behave exactly like
       the built-in scalars, allowing for selective overloading of methods. The "new" method is provided as a means of grandfathering, for classes
       that forget to provide their own "TIESCALAR" method.

       For developers wishing to write their own tied-scalar classes, the methods are summarized below. The perltie section not only documents
       these, but has sample code as well:

       TIESCALAR classname, LIST
	   The method invoked by the command "tie $scalar, classname". Associates a new scalar instance with the specified class. "LIST" would
	   represent additional arguments (along the lines of AnyDBM_File and compatriots) needed to complete the association.

       FETCH this
	   Retrieve the value of the tied scalar referenced by this.

       STORE this, value
	   Store data value in the tied scalar referenced by this.

       DESTROY this
	   Free the storage associated with the tied scalar referenced by this.  This is rarely needed, as Perl manages its memory quite well. But
	   the option exists, should a class wish to perform specific actions upon the destruction of an instance.

   Tie::Scalar vs Tie::StdScalar
       "Tie::Scalar" provides all the necessary methods, but one should realize they do not do anything useful. Calling "Tie::Scalar::FETCH" or
       "Tie::Scalar::STORE" results in a (trappable) croak. And if you inherit from "Tie::Scalar", you must provide either a "new" or a
       "TIESCALAR" method.

       If you are looking for a class that does everything for you you don't define yourself, use the "Tie::StdScalar" class, not the
       "Tie::Scalar" one.

MORE INFORMATION

       The perltie section uses a good example of tying scalars by associating process IDs with priority.

perl v5.18.2							    2014-01-06							  Tie::Scalar(3pm)