1 <?php declare(strict_types=1);
8 * Called once before traversal.
10 * Return value semantics:
11 * * null: $nodes stays as-is
12 * * otherwise: $nodes is set to the return value
14 * @param Node[] $nodes Array of nodes
16 * @return null|Node[] Array of nodes
18 public function beforeTraverse(array $nodes);
21 * Called when entering a node.
23 * Return value semantics:
25 * => $node stays as-is
26 * * NodeTraverser::DONT_TRAVERSE_CHILDREN
27 * => Children of $node are not traversed. $node stays as-is
28 * * NodeTraverser::STOP_TRAVERSAL
29 * => Traversal is aborted. $node stays as-is
31 * => $node is set to the return value
33 * @param Node $node Node
35 * @return null|int|Node Replacement node (or special return value)
37 public function enterNode(Node $node);
40 * Called when leaving a node.
42 * Return value semantics:
44 * => $node stays as-is
45 * * NodeTraverser::REMOVE_NODE
46 * => $node is removed from the parent array
47 * * NodeTraverser::STOP_TRAVERSAL
48 * => Traversal is aborted. $node stays as-is
50 * => The return value is merged into the parent array (at the position of the $node)
52 * => $node is set to the return value
54 * @param Node $node Node
56 * @return null|int|Node|Node[] Replacement node (or special return value)
58 public function leaveNode(Node $node);
61 * Called once after traversal.
63 * Return value semantics:
64 * * null: $nodes stays as-is
65 * * otherwise: $nodes is set to the return value
67 * @param Node[] $nodes Array of nodes
69 * @return null|Node[] Array of nodes
71 public function afterTraverse(array $nodes);