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Diffstat (limited to 'lib/prado/framework/Collections/TStack.php')
| -rw-r--r-- | lib/prado/framework/Collections/TStack.php | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/lib/prado/framework/Collections/TStack.php b/lib/prado/framework/Collections/TStack.php new file mode 100644 index 0000000..de78527 --- /dev/null +++ b/lib/prado/framework/Collections/TStack.php @@ -0,0 +1,260 @@ +<?php +/** + * TStack, TStackIterator classes + * + * @author Qiang Xue <qiang.xue@gmail.com> + * @link https://github.com/pradosoft/prado + * @copyright Copyright © 2005-2015 The PRADO Group + * @license https://github.com/pradosoft/prado/blob/master/COPYRIGHT + * @package System.Collections + */ + +/** + * TStack class + * + * TStack implements a stack. + * + * The typical stack operations are implemented, which include + * {@link push()}, {@link pop()} and {@link peek()}. In addition, + * {@link contains()} can be used to check if an item is contained + * in the stack. To obtain the number of the items in the stack, + * check the {@link getCount Count} property. + * + * Items in the stack may be traversed using foreach as follows, + * <code> + * foreach($stack as $item) ... + * </code> + * + * @author Qiang Xue <qiang.xue@gmail.com> + * @package System.Collections + * @since 3.0 + */ +class TStack extends TComponent implements IteratorAggregate,Countable +{ + /** + * internal data storage + * @var array + */ + private $_d=array(); + /** + * number of items + * @var integer + */ + private $_c=0; + + /** + * Constructor. + * Initializes the stack with an array or an iterable object. + * @param array|Iterator the initial data. Default is null, meaning no initialization. + * @throws TInvalidDataTypeException If data is not null and neither an array nor an iterator. + */ + public function __construct($data=null) + { + if($data!==null) + $this->copyFrom($data); + } + + /** + * @return array the list of items in stack + */ + public function toArray() + { + return $this->_d; + } + + /** + * Copies iterable data into the stack. + * Note, existing data in the list will be cleared first. + * @param mixed the data to be copied from, must be an array or object implementing Traversable + * @throws TInvalidDataTypeException If data is neither an array nor a Traversable. + */ + public function copyFrom($data) + { + if(is_array($data) || ($data instanceof Traversable)) + { + $this->clear(); + foreach($data as $item) + { + $this->_d[]=$item; + ++$this->_c; + } + } + else if($data!==null) + throw new TInvalidDataTypeException('stack_data_not_iterable'); + } + + /** + * Removes all items in the stack. + */ + public function clear() + { + $this->_c=0; + $this->_d=array(); + } + + /** + * @param mixed the item + * @return boolean whether the stack contains the item + */ + public function contains($item) + { + return array_search($item,$this->_d,true)!==false; + } + + /** + * Returns the item at the top of the stack. + * Unlike {@link pop()}, this method does not remove the item from the stack. + * @return mixed item at the top of the stack + * @throws TInvalidOperationException if the stack is empty + */ + public function peek() + { + if($this->_c===0) + throw new TInvalidOperationException('stack_empty'); + else + return $this->_d[$this->_c-1]; + } + + /** + * Pops up the item at the top of the stack. + * @return mixed the item at the top of the stack + * @throws TInvalidOperationException if the stack is empty + */ + public function pop() + { + if($this->_c===0) + throw new TInvalidOperationException('stack_empty'); + else + { + --$this->_c; + return array_pop($this->_d); + } + } + + /** + * Pushes an item into the stack. + * @param mixed the item to be pushed into the stack + */ + public function push($item) + { + ++$this->_c; + $this->_d[] = $item; + } + + /** + * Returns an iterator for traversing the items in the stack. + * This method is required by the interface IteratorAggregate. + * @return Iterator an iterator for traversing the items in the stack. + */ + public function getIterator() + { + return new ArrayIterator( $this->_d ); + } + + /** + * @return integer the number of items in the stack + */ + public function getCount() + { + return $this->_c; + } + + /** + * Returns the number of items in the stack. + * This method is required by Countable interface. + * @return integer number of items in the stack. + */ + public function count() + { + return $this->getCount(); + } +} + +/** + * TStackIterator class + * + * TStackIterator implements Iterator interface. + * + * TStackIterator is used by TStack. It allows TStack to return a new iterator + * for traversing the items in the list. + * + * @deprecated Issue 264 : ArrayIterator should be used instead + * @author Qiang Xue <qiang.xue@gmail.com> + * @package System.Collections + * @since 3.0 + */ +class TStackIterator implements Iterator +{ + /** + * @var array the data to be iterated through + */ + private $_d; + /** + * @var integer index of the current item + */ + private $_i; + /** + * @var integer count of the data items + */ + private $_c; + + /** + * Constructor. + * @param array the data to be iterated through + */ + public function __construct(&$data) + { + $this->_d=&$data; + $this->_i=0; + $this->_c=count($this->_d); + } + + /** + * Rewinds internal array pointer. + * This method is required by the interface Iterator. + */ + public function rewind() + { + $this->_i=0; + } + + /** + * Returns the key of the current array item. + * This method is required by the interface Iterator. + * @return integer the key of the current array item + */ + public function key() + { + return $this->_i; + } + + /** + * Returns the current array item. + * This method is required by the interface Iterator. + * @return mixed the current array item + */ + public function current() + { + return $this->_d[$this->_i]; + } + + /** + * Moves the internal pointer to the next array item. + * This method is required by the interface Iterator. + */ + public function next() + { + $this->_i++; + } + + /** + * Returns whether there is an item at current position. + * This method is required by the interface Iterator. + * @return boolean + */ + public function valid() + { + return $this->_i<$this->_c; + } +} + |