Chris@13: <?php declare(strict_types=1);
Chris@0: 
Chris@0: namespace PhpParser;
Chris@0: 
Chris@0: interface NodeVisitor
Chris@0: {
Chris@0:     /**
Chris@0:      * Called once before traversal.
Chris@0:      *
Chris@0:      * Return value semantics:
Chris@0:      *  * null:      $nodes stays as-is
Chris@0:      *  * otherwise: $nodes is set to the return value
Chris@0:      *
Chris@0:      * @param Node[] $nodes Array of nodes
Chris@0:      *
Chris@0:      * @return null|Node[] Array of nodes
Chris@0:      */
Chris@0:     public function beforeTraverse(array $nodes);
Chris@0: 
Chris@0:     /**
Chris@0:      * Called when entering a node.
Chris@0:      *
Chris@0:      * Return value semantics:
Chris@0:      *  * null
Chris@0:      *        => $node stays as-is
Chris@0:      *  * NodeTraverser::DONT_TRAVERSE_CHILDREN
Chris@0:      *        => Children of $node are not traversed. $node stays as-is
Chris@0:      *  * NodeTraverser::STOP_TRAVERSAL
Chris@0:      *        => Traversal is aborted. $node stays as-is
Chris@0:      *  * otherwise
Chris@0:      *        => $node is set to the return value
Chris@0:      *
Chris@0:      * @param Node $node Node
Chris@0:      *
Chris@13:      * @return null|int|Node Replacement node (or special return value)
Chris@0:      */
Chris@0:     public function enterNode(Node $node);
Chris@0: 
Chris@0:     /**
Chris@0:      * Called when leaving a node.
Chris@0:      *
Chris@0:      * Return value semantics:
Chris@0:      *  * null
Chris@0:      *        => $node stays as-is
Chris@0:      *  * NodeTraverser::REMOVE_NODE
Chris@0:      *        => $node is removed from the parent array
Chris@0:      *  * NodeTraverser::STOP_TRAVERSAL
Chris@0:      *        => Traversal is aborted. $node stays as-is
Chris@0:      *  * array (of Nodes)
Chris@0:      *        => The return value is merged into the parent array (at the position of the $node)
Chris@0:      *  * otherwise
Chris@0:      *        => $node is set to the return value
Chris@0:      *
Chris@0:      * @param Node $node Node
Chris@0:      *
Chris@13:      * @return null|int|Node|Node[] Replacement node (or special return value)
Chris@0:      */
Chris@0:     public function leaveNode(Node $node);
Chris@0: 
Chris@0:     /**
Chris@0:      * Called once after traversal.
Chris@0:      *
Chris@0:      * Return value semantics:
Chris@0:      *  * null:      $nodes stays as-is
Chris@0:      *  * otherwise: $nodes is set to the return value
Chris@0:      *
Chris@0:      * @param Node[] $nodes Array of nodes
Chris@0:      *
Chris@0:      * @return null|Node[] Array of nodes
Chris@0:      */
Chris@0:     public function afterTraverse(array $nodes);
Chris@13: }