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<?php |
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/** |
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* Part of twLib |
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* http://www.thomaswhiston.com |
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* [email protected] |
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* Created by PhpStorm. |
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* User: Thomas Whiston |
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* Date: 03/02/2016 |
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* Time: 20:44 |
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*/ |
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namespace twhiston\twLib\Reference; |
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use twhiston\twLib\Exception\TwLibException; |
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/** |
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* Class Stack |
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* Basic reference stack |
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* add items to the stack with the takeReference function |
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* Though this class has array access it will throw an exception if you attempt to add anything by reference as its impossible |
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* @package twhiston\twLib\Reference |
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*/ |
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class Stack implements \ArrayAccess, \Iterator, \Countable |
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{ |
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/** |
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* @var Reference[] |
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*/ |
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private $stack; |
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/** |
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* @var int |
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*/ |
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private $pos; |
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/** |
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* Stack constructor. |
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*/ |
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public function __construct() |
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{ |
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$this->pos = 0; |
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} |
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/** |
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* @param $data |
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*/ |
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public function takeReference(&$data) |
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{ |
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if ($data instanceof Reference) { |
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$this->stack[] = $data; |
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} else { |
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$this->stack[] = new Reference($data); |
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} |
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} |
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/** |
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* @inheritDoc |
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*/ |
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public function offsetExists($offset) |
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{ |
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return isset($this->stack[$offset]); |
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} |
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/** |
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* @inheritDoc |
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*/ |
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public function offsetGet($offset) |
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{ |
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return isset($this->stack[$offset]) ? $this->stack[$offset] : null; |
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} |
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/** |
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* @inheritDoc |
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*/ |
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1 |
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public function offsetSet($offset, $value) |
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{ |
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throw new TwLibException( |
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'Do not set stack references with the array operator' |
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); |
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} |
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/** |
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* @inheritDoc |
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*/ |
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1 |
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public function offsetUnset($offset) |
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{ |
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1 |
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unset($this->stack[$offset]); |
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1 |
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} |
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/** |
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* @inheritDoc |
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*/ |
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public function current() |
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{ |
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$this->stack[$this->pos]; |
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} |
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/** |
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* @inheritDoc |
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*/ |
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1 |
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public function next() |
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{ |
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1 |
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++$this->pos; |
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1 |
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} |
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/** |
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* @inheritDoc |
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*/ |
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1 |
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public function key() |
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{ |
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1 |
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return $this->pos; |
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} |
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/** |
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* @inheritDoc |
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*/ |
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1 |
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public function valid() |
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{ |
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1 |
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return isset($this->stack[$this->pos]); |
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} |
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/** |
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* @inheritDoc |
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*/ |
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1 |
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public function rewind() |
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{ |
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1 |
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$this->pos = 0; |
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1 |
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} |
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/** |
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* @return \twhiston\twLib\Reference\Reference |
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*/ |
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2 |
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public function &top() |
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{ |
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return $this->stack[count($this->stack) - 1]; |
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} |
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/** |
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* Remove the Reference from the top of the stack |
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*/ |
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2 |
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public function pop() |
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{ |
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return array_pop($this->stack); |
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} |
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/** |
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* Remove the Reference from the bottom of the stack |
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*/ |
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1 |
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public function shift() |
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{ |
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1 |
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return array_shift($this->stack); |
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} |
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/** |
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155
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* @inheritDoc |
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*/ |
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2 |
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public function count() |
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{ |
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return count($this->stack); |
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} |
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162
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163
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} |
