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