NodeTraverser.php
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<?php
namespace PhpParser;
class NodeTraverser implements NodeTraverserInterface
{
/**
* @var NodeVisitor[] Visitors
*/
protected $visitors;
/**
* @var bool
*/
private $cloneNodes;
/**
* Constructs a node traverser.
*
* @param bool $cloneNodes Should the traverser clone the nodes when traversing the AST
*/
public function __construct($cloneNodes = false) {
$this->visitors = array();
$this->cloneNodes = $cloneNodes;
}
/**
* Adds a visitor.
*
* @param NodeVisitor $visitor Visitor to add
*/
public function addVisitor(NodeVisitor $visitor) {
$this->visitors[] = $visitor;
}
/**
* Removes an added visitor.
*
* @param NodeVisitor $visitor
*/
public function removeVisitor(NodeVisitor $visitor) {
foreach ($this->visitors as $index => $storedVisitor) {
if ($storedVisitor === $visitor) {
unset($this->visitors[$index]);
break;
}
}
}
/**
* Traverses an array of nodes using the registered visitors.
*
* @param Node[] $nodes Array of nodes
*
* @return Node[] Traversed array of nodes
*/
public function traverse(array $nodes) {
foreach ($this->visitors as $visitor) {
if (null !== $return = $visitor->beforeTraverse($nodes)) {
$nodes = $return;
}
}
$nodes = $this->traverseArray($nodes);
foreach ($this->visitors as $visitor) {
if (null !== $return = $visitor->afterTraverse($nodes)) {
$nodes = $return;
}
}
return $nodes;
}
protected function traverseNode(Node $node) {
if ($this->cloneNodes) {
$node = clone $node;
}
foreach ($node->getSubNodeNames() as $name) {
$subNode =& $node->$name;
if (is_array($subNode)) {
$subNode = $this->traverseArray($subNode);
} elseif ($subNode instanceof Node) {
$traverseChildren = true;
foreach ($this->visitors as $visitor) {
$return = $visitor->enterNode($subNode);
if (self::DONT_TRAVERSE_CHILDREN === $return) {
$traverseChildren = false;
} else if (null !== $return) {
$subNode = $return;
}
}
if ($traverseChildren) {
$subNode = $this->traverseNode($subNode);
}
foreach ($this->visitors as $visitor) {
if (null !== $return = $visitor->leaveNode($subNode)) {
if (is_array($return)) {
throw new \LogicException(
'leaveNode() may only return an array ' .
'if the parent structure is an array'
);
}
$subNode = $return;
}
}
}
}
return $node;
}
protected function traverseArray(array $nodes) {
$doNodes = array();
foreach ($nodes as $i => &$node) {
if (is_array($node)) {
$node = $this->traverseArray($node);
} elseif ($node instanceof Node) {
$traverseChildren = true;
foreach ($this->visitors as $visitor) {
$return = $visitor->enterNode($node);
if (self::DONT_TRAVERSE_CHILDREN === $return) {
$traverseChildren = false;
} else if (null !== $return) {
$node = $return;
}
}
if ($traverseChildren) {
$node = $this->traverseNode($node);
}
foreach ($this->visitors as $visitor) {
$return = $visitor->leaveNode($node);
if (self::REMOVE_NODE === $return) {
$doNodes[] = array($i, array());
break;
} elseif (is_array($return)) {
$doNodes[] = array($i, $return);
break;
} elseif (null !== $return) {
$node = $return;
}
}
}
}
if (!empty($doNodes)) {
while (list($i, $replace) = array_pop($doNodes)) {
array_splice($nodes, $i, 1, $replace);
}
}
return $nodes;
}
}