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Perl Documentation

NAME

Tie::Array - base class for tied arrays

SYNOPSIS

package Tie::NewArray;
use Tie::Array;
@ISA = ('Tie::Array');
# mandatory methods
sub TIEARRAY { ... }
sub FETCH { ... }
sub FETCHSIZE { ... }
sub STORE { ... }       # mandatory if elements writeable
sub STORESIZE { ... }   # mandatory if elements can be added/deleted
sub EXISTS { ... }      # mandatory if exists() expected to work
sub DELETE { ... }      # mandatory if delete() expected to work
# optional methods - for efficiency
sub CLEAR { ... }
sub PUSH { ... }
sub POP { ... }
sub SHIFT { ... }
sub UNSHIFT { ... }
sub SPLICE { ... }
sub EXTEND { ... }
sub DESTROY { ... }
package Tie::NewStdArray;
use Tie::Array;
@ISA = ('Tie::StdArray');
# all methods provided by default
package main;
$object = tie @somearray,'Tie::NewArray';
$object = tie @somearray,'Tie::StdArray';
$object = tie @somearray,'Tie::NewStdArray';

DESCRIPTION

This module provides methods for array-tying classes. See perltie for a list of the functions required in order to tie an array to a package. The basic Tie::Array package provides stub DESTROY, and EXTEND methods that do nothing, stub DELETE and EXISTS methods that croak() if the delete() or exists() builtins are ever called on the tied array, and implementations of PUSH, POP, SHIFT, UNSHIFT, SPLICE and CLEAR in terms of basic FETCH, STORE, FETCHSIZE, STORESIZE.

The Tie::StdArray package provides efficient methods required for tied arrays which are implemented as blessed references to an "inner" perl array. It inherits from Tie::Array, and should cause tied arrays to behave exactly like standard arrays, allowing for selective overloading of methods.

For developers wishing to write their own tied arrays, the required methods are briefly defined below. See the perltie section for more detailed descriptive, as well as example code:

CAVEATS

There is no support at present for tied @ISA. There is a potential conflict between magic entries needed to notice setting of @ISA, and those needed to implement 'tie'.

AUTHOR

Nick Ing-Simmons <nik@tiuk.ti.com>