1<?php declare(strict_types=1); 2 3namespace PhpParser; 4 5interface NodeVisitor { 6 /** 7 * If NodeVisitor::enterNode() returns DONT_TRAVERSE_CHILDREN, child nodes 8 * of the current node will not be traversed for any visitors. 9 * 10 * For subsequent visitors enterNode() will still be called on the current 11 * node and leaveNode() will also be invoked for the current node. 12 */ 13 public const DONT_TRAVERSE_CHILDREN = 1; 14 15 /** 16 * If NodeVisitor::enterNode() or NodeVisitor::leaveNode() returns 17 * STOP_TRAVERSAL, traversal is aborted. 18 * 19 * The afterTraverse() method will still be invoked. 20 */ 21 public const STOP_TRAVERSAL = 2; 22 23 /** 24 * If NodeVisitor::leaveNode() returns REMOVE_NODE for a node that occurs 25 * in an array, it will be removed from the array. 26 * 27 * For subsequent visitors leaveNode() will still be invoked for the 28 * removed node. 29 */ 30 public const REMOVE_NODE = 3; 31 32 /** 33 * If NodeVisitor::enterNode() returns DONT_TRAVERSE_CURRENT_AND_CHILDREN, child nodes 34 * of the current node will not be traversed for any visitors. 35 * 36 * For subsequent visitors enterNode() will not be called as well. 37 * leaveNode() will be invoked for visitors that has enterNode() method invoked. 38 */ 39 public const DONT_TRAVERSE_CURRENT_AND_CHILDREN = 4; 40 41 /** 42 * If NodeVisitor::enterNode() or NodeVisitor::leaveNode() returns REPLACE_WITH_NULL, 43 * the node will be replaced with null. This is not a legal return value if the node is part 44 * of an array, rather than another node. 45 */ 46 public const REPLACE_WITH_NULL = 5; 47 48 /** 49 * Called once before traversal. 50 * 51 * Return value semantics: 52 * * null: $nodes stays as-is 53 * * otherwise: $nodes is set to the return value 54 * 55 * @param Node[] $nodes Array of nodes 56 * 57 * @return null|Node[] Array of nodes 58 */ 59 public function beforeTraverse(array $nodes); 60 61 /** 62 * Called when entering a node. 63 * 64 * Return value semantics: 65 * * null 66 * => $node stays as-is 67 * * array (of Nodes) 68 * => The return value is merged into the parent array (at the position of the $node) 69 * * NodeVisitor::REMOVE_NODE 70 * => $node is removed from the parent array 71 * * NodeVisitor::REPLACE_WITH_NULL 72 * => $node is replaced with null 73 * * NodeVisitor::DONT_TRAVERSE_CHILDREN 74 * => Children of $node are not traversed. $node stays as-is 75 * * NodeVisitor::DONT_TRAVERSE_CURRENT_AND_CHILDREN 76 * => Further visitors for the current node are skipped, and its children are not 77 * traversed. $node stays as-is. 78 * * NodeVisitor::STOP_TRAVERSAL 79 * => Traversal is aborted. $node stays as-is 80 * * otherwise 81 * => $node is set to the return value 82 * 83 * @param Node $node Node 84 * 85 * @return null|int|Node|Node[] Replacement node (or special return value) 86 */ 87 public function enterNode(Node $node); 88 89 /** 90 * Called when leaving a node. 91 * 92 * Return value semantics: 93 * * null 94 * => $node stays as-is 95 * * NodeVisitor::REMOVE_NODE 96 * => $node is removed from the parent array 97 * * NodeVisitor::REPLACE_WITH_NULL 98 * => $node is replaced with null 99 * * NodeVisitor::STOP_TRAVERSAL 100 * => Traversal is aborted. $node stays as-is 101 * * array (of Nodes) 102 * => The return value is merged into the parent array (at the position of the $node) 103 * * otherwise 104 * => $node is set to the return value 105 * 106 * @param Node $node Node 107 * 108 * @return null|int|Node|Node[] Replacement node (or special return value) 109 */ 110 public function leaveNode(Node $node); 111 112 /** 113 * Called once after traversal. 114 * 115 * Return value semantics: 116 * * null: $nodes stays as-is 117 * * otherwise: $nodes is set to the return value 118 * 119 * @param Node[] $nodes Array of nodes 120 * 121 * @return null|Node[] Array of nodes 122 */ 123 public function afterTraverse(array $nodes); 124} 125
