This module provides some skeletal methods for hash-tying classes. See
the perltie manpage for a list of the functions required in order to tie a hash to a package.
The basic Tie::Hash package provides a new method, as well as methods TIEHASH, EXISTS and CLEAR. The Tie::StdHash package provides most methods required for hashes in the perltie manpage. It inherits from
Tie::Hash, and causes tied hashes to behave exactly like standard hashes, allowing
for selective overloading of methods. The new method is provided as grandfathering in the case a class forgets to include
a TIEHASH method.
For developers wishing to write their own tied hashes, the required methods
are briefly defined below. See the the perltie manpage section for more detailed descriptive, as well as example code:
The method invoked by the command tie %hash, classname. Associates a new hash instance with the specified class. LIST would represent additional arguments (along the lines of the AnyDBM_File manpage and compatriots) needed to complete the association.
The the perltie manpage documentation includes a method called DESTROY as a necessary method for tied hashes. Neither Tie::Hash nor Tie::StdHash
define a default for this method. This is a standard for class packages,
but may be omitted in favor of a simple default.
The packages relating to various DBM-related implemetations (DB_File,
NDBM_File, etc.) show examples of general tied hashes, as does the
Config module. While these do not utilize Tie::Hash, they serve as good working examples.