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+<?php
+
+/** @file iteratoriterator.inc
+ * @ingroup SPL
+ * @brief class IteratorIterator
+ * @author Marcus Boerger
+ * @date 2003 - 2009
+ *
+ * SPL - Standard PHP Library
+ */
+
+/** @ingroup SPL
+ * @brief Basic Iterator wrapper
+ * @since PHP 5.1
+ *
+ * This iterator wrapper allows to convert anything that is traversable into
+ * an Iterator. It is very important to understand that most classes that do
+ * not implement Iterator have their reasone to. Most likely they do not allow
+ * the full Iterator feature set. If so you need to provide techniques to
+ * prevent missuse. If you do not you must expect exceptions or fatal erros.
+ *
+ * It is also possible to derive the class and implement IteratorAggregate by
+ * downcasting the instances returned in getIterator. See the following
+ * example (assuming BaseClass implements Traversable):
+ \code
+ class SomeClass extends BaseClass implements IteratorAggregate
+ {
+ function getIterator()
+ {
+ return new IteratorIterator($this, 'BaseClass');
+ }
+ }
+ \endcode
+ *
+ * As you can see in the example this approach requires that the class to
+ * downcast to is actually a base class of the specified iterator to wrap.
+ * Omitting the downcast in the above example would result in an endless loop
+ * since IteratorIterator::__construct() would call SomeClass::getIterator().
+ */
+class IteratorIterator implements OuterIterator
+{
+ /** Construct an IteratorIterator from an Iterator or an IteratorAggregate.
+ *
+ * @param iterator inner iterator
+ * @param classname optional class the iterator has to be downcasted to
+ */
+ function __construct(Traversable $iterator, $classname = null)
+ {
+ if ($iterator instanceof IteratorAggregate)
+ {
+ $iterator = $iterator->getIterator();
+ }
+ if ($iterator instanceof Iterator)
+ {
+ $this->iterator = $iterator;
+ }
+ else
+ {
+ throw new Exception("Classes that only implement Traversable can be wrapped only after converting class IteratorIterator into c code");
+ }
+ }
+
+ /** \return the inner iterator as passed to the constructor
+ */
+ function getInnerIterator()
+ {
+ return $this->iterator;
+ }
+
+ /** \return whether the iterator is valid
+ */
+ function valid()
+ {
+ return $this->iterator->valid();
+ }
+
+ /** \return current key
+ */
+ function key()
+ {
+ return $this->iterator->key();
+ }
+
+ /** \return current value
+ */
+ function current()
+ {
+ return $this->iterator->current();
+ }
+
+ /** forward to next element
+ */
+ function next()
+ {
+ return $this->iterator->next();
+ }
+
+ /** rewind to the first element
+ */
+ function rewind()
+ {
+ return $this->iterator->rewind();
+ }
+
+ /** Aggregate the inner iterator
+ *
+ * @param func Name of method to invoke
+ * @param params Array of parameters to pass to method
+ */
+ function __call($func, $params)
+ {
+ return call_user_func_array(array($this->iterator, $func), $params);
+ }
+
+ /** The inner iterator must be private because when this class will be
+ * converted to c code it won't no longer be available.
+ */
+ private $iterator;
+}
+
+?>