Inheritance diagram for SplDoublyLinkedList:

Collaboration diagram for SplDoublyLinkedList:

Public Member Functions
	bottom ()
	count ()
	current ()
	getIteratorMode ()
	isEmpty ()
	key ()
	next ()
	offsetExists ($offset)
	offsetGet ($offset)
	offsetSet ($offset, $value)
	offsetUnset ($offset)
	pop ()
	push ($data)
	rewind ()
	setIteratorMode ($mode)
	shift ()
	top ()
	unshift ($data)
	valid ()
Public Attributes
const	IT_MODE_DELETE = 0x00000001
const	IT_MODE_FIFO = 0x00000000
const	IT_MODE_KEEP = 0x00000000
const	IT_MODE_LIFO = 0x00000002
Protected Attributes
	$_it_mode = 0
	$_it_pos = 0
	$_llist = array()

Detailed Description

Doubly Linked List.

Since:: PHP 5.3

The SplDoublyLinkedList class provides the main functionalities of a doubly linked list (DLL).

Note:: The following userland implementation of Iterator is a bit different from the internal one. Internally, iterators generated by nested foreachs are independent, while they share the same traverse pointer in userland.

Definition at line 22 of file spldoublylinkedlist.inc.

Member Function Documentation

SplDoublyLinkedList::bottom ( )

Returns:: the element at the end of the DLL.

Definition at line 97 of file spldoublylinkedlist.inc.

    {
        return reset($this->_llist);
    }

SplDoublyLinkedList::count ( )

Returns:: number elements in the DLL.

Implements Countable.

Definition at line 104 of file spldoublylinkedlist.inc.

Referenced by isEmpty(), offsetGet(), offsetSet(), offsetUnset(), pop(), rewind(), and shift().

    {
        return count($this->_llist);
    }

SplDoublyLinkedList::current ( )

Returns:: current object

Implements Iterator.

Definition at line 170 of file spldoublylinkedlist.inc.

    {
        return $this->_llist[$this->_it_pos];
    }

SplDoublyLinkedList::getIteratorMode ( )

Returns:: the current iteration mode

See also:: setIteratorMode

Definition at line 138 of file spldoublylinkedlist.inc.

    {
        return $this->_it_mode;
    }

SplDoublyLinkedList::isEmpty ( )

Returns:: whether the DLL is empty.

Definition at line 111 of file spldoublylinkedlist.inc.

References count().

    {
        return ($this->count() == 0);
    }

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SplDoublyLinkedList::key ( )

Returns:: current key

Implements Iterator.

Definition at line 163 of file spldoublylinkedlist.inc.

    {
        return $this->_it_pos;
    }

SplDoublyLinkedList::next ( )

Forward to next element.

Implements Iterator.

Definition at line 177 of file spldoublylinkedlist.inc.

References pop(), and shift().

    {
        if ($this->_it_mode & self::IT_MODE_LIFO) {
            if ($this->_it_mode & self::IT_MODE_DELETE) {
                $this->pop();
            }
            $this->_it_pos--;
        } else {
            if ($this->_it_mode & self::IT_MODE_DELETE) {
                $this->shift();
            } else {
                $this->_it_pos++;
            }
        }
    }

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SplDoublyLinkedList::offsetExists ( $ offset )

Returns:: whether a certain offset exists in the DLL

Parameters:

$offset The offset

Exceptions:

OutOfRangeException If the offset is either invalid or out of range.

Implements ArrayAccess.

Definition at line 199 of file spldoublylinkedlist.inc.

    {
        if (!is_numeric($offset)) {
            throw new OutOfRangeException("Offset invalid or out of range");
        } else {
            return array_key_exists($offset, $this->_llist);
        }
    }

SplDoublyLinkedList::offsetGet ( $ offset )

Returns:: the data at a certain offset in the DLL

Parameters:

$offset The offset

Exceptions:

OutOfRangeException If the offset is either invalid or out of range.

Implements ArrayAccess.

Definition at line 214 of file spldoublylinkedlist.inc.

References count().

    {
        if ($this->_it_mode & self::IT_MODE_LIFO) {
            $realOffset = count($this->_llist)-$offset;
        } else {
            $realOffset = $offset;
        }

        if (!is_numeric($offset) || !array_key_exists($realOffset, $this->_llist)) {
            throw new OutOfRangeException("Offset invalid or out of range");
        } else {
            return $this->_llist[$realOffset];
        }
    }

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SplDoublyLinkedList::offsetSet	(	$	offset,
		$	value
	)

Defines the data at a certain offset in the DLL.

Parameters:

$offset	The offset
$value	New value

Exceptions:

OutOfRangeException If the offset is either invalid or out of range.

Implements ArrayAccess.

Definition at line 236 of file spldoublylinkedlist.inc.

References count(), and push().

    {
        if ($offset === null) {
            return $this->push($value);
        }

        if ($this->_it_mode & self::IT_MODE_LIFO) {
            $realOffset = count($this->_llist)-$offset;
        } else {
            $realOffset = $offset;
        }

        if (!is_numeric($offset) || !array_key_exists($realOffset, $this->_llist)) {
            throw new OutOfRangeException("Offset invalid or out of range");
        } else {
            $this->_llist[$realOffset] = $value;
        }
    }

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SplDoublyLinkedList::offsetUnset ( $ offset )

Unsets the element at a certain offset in the DLL.

Parameters:

$offset The offset

Exceptions:

OutOfRangeException If the offset is either invalid or out of range.

Implements ArrayAccess.

Definition at line 261 of file spldoublylinkedlist.inc.

References count().

    {
        if ($this->_it_mode & self::IT_MODE_LIFO) {
            $realOffset = count($this->_llist)-$offset;
        } else {
            $realOffset = $offset;
        }

        if (!is_numeric($offset) || !array_key_exists($realOffset, $this->_llist)) {
            throw new OutOfRangeException("Offset invalid or out of range");
        } else {
            array_splice($this->_llist, $realOffset, 1);
        }
    }

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SplDoublyLinkedList::pop ( )

Returns:: the element popped from the end of the DLL.

Exceptions:

RuntimeException If the datastructure is empty.

Definition at line 51 of file spldoublylinkedlist.inc.

References count().

Referenced by next().

    {
        if (count($this->_llist) == 0) {
            throw new RuntimeException("Can't pop from an empty datastructure");
        }
        return array_pop($this->_llist);
    }

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SplDoublyLinkedList::push ( $ data )

Pushes an element to the end of the DLL.

Parameters:

$data variable to add to the DLL.

Definition at line 73 of file spldoublylinkedlist.inc.

Referenced by SplQueue\enqueue(), and offsetSet().

    {
        array_push($this->_llist, $data);
        return true;
    }

SplDoublyLinkedList::rewind ( )

Rewind to top iterator as set in constructor.

Implements Iterator.

Definition at line 145 of file spldoublylinkedlist.inc.

References count().

    {
        if ($this->_it_mode & self::IT_MODE_LIFO) {
            $this->_it_pos = count($this->_llist)-1;
        } else {
            $this->_it_pos = 0;
        }
    }

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SplDoublyLinkedList::setIteratorMode ( $ mode )

Changes the iteration mode.

There are two orthogonal sets of modes that can be set:

The direction of the iteration (either one or the other)
- SplDoublyLnkedList::IT_MODE_LIFO (Stack style)
- SplDoublyLnkedList::IT_MODE_FIFO (Queue style)

The behavior of the iterator (either one or the other)
- SplDoublyLnkedList::IT_MODE_DELETE (Elements are deleted by the iterator)
- SplDoublyLnkedList::IT_MODE_KEEP (Elements are traversed by the iterator)

The default mode is 0 : SplDoublyLnkedList::IT_MODE_FIFO | SplDoublyLnkedList::IT_MODE_KEEP

Parameters:

$mode new mode of iteration

Reimplemented in SplQueue, and SplStack.

Definition at line 130 of file spldoublylinkedlist.inc.

    {
        $this->_it_mode = $mode;
    }

SplDoublyLinkedList::shift ( )

Returns:: the element shifted from the beginning of the DLL.

Exceptions:

RuntimeException If the datastructure is empty.

Definition at line 62 of file spldoublylinkedlist.inc.

References count().

Referenced by SplQueue\dequeue(), and next().

    {
        if (count($this->_llist) == 0) {
            throw new RuntimeException("Can't shift from an empty datastructure");
        }
        return array_shift($this->_llist);
    }

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SplDoublyLinkedList::top ( )

Returns:: the element at the beginning of the DLL.

Definition at line 90 of file spldoublylinkedlist.inc.

    {
        return end($this->_llist);
    }

SplDoublyLinkedList::unshift ( $ data )

Adds an element to the beginning of the DLL.

Parameters:

$data variable to add to the DLL.

Definition at line 82 of file spldoublylinkedlist.inc.

    {
        array_unshift($this->_llist, $data);
        return true;
    }

SplDoublyLinkedList::valid ( )

Returns:: whether iterator is valid

Implements Iterator.

Definition at line 156 of file spldoublylinkedlist.inc.

    {
        return array_key_exists($this->_it_pos, $this->_llist);
    }

Member Data Documentation

SplDoublyLinkedList::$_it_mode = 0 [protected]

Reimplemented in SplQueue, and SplStack.

Definition at line 25 of file spldoublylinkedlist.inc.

SplDoublyLinkedList::$_it_pos = 0 [protected]

Definition at line 26 of file spldoublylinkedlist.inc.

SplDoublyLinkedList::$_llist = array() [protected]

Definition at line 24 of file spldoublylinkedlist.inc.

const SplDoublyLinkedList::IT_MODE_DELETE = 0x00000001

Iterator mode.

See also:: setIteratorMode

Definition at line 46 of file spldoublylinkedlist.inc.

const SplDoublyLinkedList::IT_MODE_FIFO = 0x00000000

Iterator mode.

See also:: setIteratorMode

Definition at line 36 of file spldoublylinkedlist.inc.

const SplDoublyLinkedList::IT_MODE_KEEP = 0x00000000

Iterator mode.

See also:: setIteratorMode

Definition at line 41 of file spldoublylinkedlist.inc.

const SplDoublyLinkedList::IT_MODE_LIFO = 0x00000002

Iterator mode.

See also:: setIteratorMode

Definition at line 31 of file spldoublylinkedlist.inc.

The documentation for this class was generated from the following file:

spldoublylinkedlist.inc

Public Member Functions

Public Attributes

Protected Attributes

Detailed Description

Member Function Documentation

Member Data Documentation