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8.215. Tie::Array, Tie::StdArray

Provides methods for array-tying
classes. (See the perltie manpage for the
functions needed for tying an array to a package.) The basic
Tie::Array package provides stub DELETE and EXTEND methods and
implements PUSH, POP, SHIFT, UNSHIFT, SPLICE, and CLEAR in terms of
basic FETCH, STORE, FETCHSIZE, and STORESIZE.

Tie::StdArray inherits from Tie::Array and provides the methods
needed for tied arrays implemented as blessed references to an
"inner" Perl array. It causes tied
arrays to behave like standard arrays, allowing for selective method
overloading.

See the perltie manpage for more detailed
information and for examples. To write your own tied arrays, use the
following required methods.

TIEARRAY classname, list

Constructor. This method is invoked by the command
tie @array ,
classname. Associates an array instance
with the specified class. list represents
additional arguments needed to complete the association. Should
return an object of a class that provides the remaining methods.

CLEAR this

Clears all values from the tied array associated with object
this.

DESTROY this

Normal object destructor.

EXTEND this, count

Doesn't need to do anything. Provides information
that the array will likely grow to have
count entries.

FETCH this, index

Retrieves the data item in index for the
tied array associated with object this.

FETCHSIZE this

Returns the number of items in the tied array associated with object
this.

POP this

Removes the last element from the array and returns it.

PUSH this, list

Appends elements of list to the array.

SHIFT this

Removes and returns the first element of the array, shifting the
remaining elements down.

SPLICE this, offset, length, list

Performs the equivalent of a splice on the
array. Returns a list of the original
length elements at the specified offset.
The arguments are:

offset

Optional. Defaults to 0; if negative, counts back
from the end of the array.

length

Optional. Defaults to the rest of the array.

list

May be empty.

STORE this, index, value

Stores value of a data item into index for
the tied array associated with object
this. If the resulting array is larger
than the class's mapping for the array,
undef should be returned for new positions.

STORESIZE this, count

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

UNSHIFT this, list

Inserts list elements at the beginning of
the array, moving existing elements up to make room.