Tie::Array - base class for tied arrays
package 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 # optional methods - for efficiency sub CLEAR { ... } sub PUSH { ... } sub POP { ... } sub SHIFT { ... } sub UNSHIFT { ... } sub SPLICE { ... } sub EXTEND { ... } sub DESTROY { ... }
package 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;
This module provides methods for array-tying classes. See
the perltie manpage for a list of the functions required in order to tie an array to a package.
The basic Tie::Array package provides stub DELETE
and EXTEND methods, 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 the perltie manpage section for more detailed descriptive, as well as example code:
tie @array, classname
. Associates an array 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 method should
return an object of a class which provides the methods below.
offset is optional and defaults to zero, negative values count back from the end of the array.
length is optional and defaults to rest of the array.
LIST may be empty.
Returns a list of the original length elements at offset.
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'.
Very little consideration has been given to the behaviour of tied arrays
when $[
is not default value of zero.
Nick Ing-Simmons <nik@tiuk.ti.com>
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