Tie::Array - phpMan

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:

    TIEARRAY classname, LIST
        The class method is invoked by the command "tie @array, classname".
        Associates an array instance with the specified class. "LIST" would
        represent additional arguments (along the lines of AnyDBM_File and
        compatriots) needed to complete the association. The method should
        return an object of a class which provides the methods below.

    STORE this, index, value
        Store datum *value* into *index* for the tied array associated with
        object *this*. If this makes the array larger then class's mapping
        of "undef" should be returned for new positions.

    FETCH this, index
        Retrieve the datum in *index* for the tied array associated with
        object *this*.

    FETCHSIZE this
        Returns the total number of items in the tied array associated with
        object *this*. (Equivalent to "scalar(@array)").

    STORESIZE this, count
        Sets the total number of items in the tied array associated with
        object *this* to be *count*. If this makes the array larger then
        class's mapping of "undef" should be returned for new positions. If
        the array becomes smaller then entries beyond count should be
        deleted.

    EXTEND this, count
        Informative call that array is likely to grow to have *count*
        entries. Can be used to optimize allocation. This method need do
        nothing.

    EXISTS this, key
        Verify that the element at index *key* exists in the tied array
        *this*.

        The Tie::Array implementation is a stub that simply croaks.

    DELETE this, key
        Delete the element at index *key* from the tied array *this*.

        The Tie::Array implementation is a stub that simply croaks.

    CLEAR this
        Clear (remove, delete, ...) all values from the tied array
        associated with object *this*.

    DESTROY this
        Normal object destructor method.

    PUSH this, LIST
        Append elements of LIST to the array.

    POP this
        Remove last element of the array and return it.

    SHIFT this
        Remove the first element of the array (shifting other elements down)
        and return it.

    UNSHIFT this, LIST
        Insert LIST elements at the beginning of the array, moving existing
        elements up to make room.

    SPLICE this, offset, length, LIST
        Perform the equivalent of "splice" on the array.

        *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*.

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 AT tiuk.com>