added Traverser

src/Neon/Node.php

@@ -22,4 +22,11 @@ abstract class Node
 
 	/** @return mixed */
 	abstract public function toValue();
+
+
+	/** @return self[] */
+	public function getSubNodes(): array
+	{
+		return [];
+	}
 }

src/Neon/Node/ArrayItemNode.php

@@ -47,4 +47,10 @@ public function toValue()
 	{
 		throw new \LogicException;
 	}
+
+
+	public function getSubNodes(): array
+	{
+		return $this->key ? [$this->key, $this->value] : [$this->value];
+	}
 }

src/Neon/Node/ArrayNode.php

@@ -33,4 +33,10 @@ public function toValue(): array
 	{
 		return ArrayItemNode::itemsToArray($this->items);
 	}
+
+
+	public function getSubNodes(): array
+	{
+		return $this->items;
+	}
 }

src/Neon/Node/EntityChainNode.php

@@ -36,4 +36,10 @@ public function toValue(): Neon\Entity
 		}
 		return new Neon\Entity(Neon\Neon::CHAIN, $entities);
 	}
+
+
+	public function getSubNodes(): array
+	{
+		return $this->chain;
+	}
 }

src/Neon/Traverser.php

@@ -0,0 +1,35 @@
+<?php
+
+/**
+ * This file is part of the Nette Framework (https://nette.org)
+ * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
+ */
+
+declare(strict_types=1);
+
+namespace Nette\Neon;
+
+
+/** @internal */
+final class Traverser
+{
+	/** @var callable(Node): void */
+	private $callback;
+
+
+	public function traverse(Node $node, callable $callback): Node
+	{
+		$this->callback = $callback;
+		return $this->traverseNode($node);
+	}
+
+
+	private function traverseNode(Node $node): Node
+	{
+		($this->callback)($node);
+		foreach ($node->getSubNodes() as $subnode) {
+			$this->traverseNode($subnode);
+		}
+		return $node;
+	}
+}

tests/Neon/Traverser.phpt

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+use Nette\Neon;
+use Nette\Neon\Node;
+use Nette\Neon\Node\EntityNode;
+use Nette\Neon\Node\LiteralNode;
+use Tester\Assert;
+
+
+require __DIR__ . '/../bootstrap.php';
+
+$visitor = function (Node $node) {
+	if ($node instanceof EntityNode) {
+		foreach ($node->attributes as $i => $attr) {
+			if (!$attr->key) {
+				$attr->key = new LiteralNode("key$i");
+			}
+		}
+	}
+};
+
+$decoder = new Neon\Decoder;
+$node = $decoder->parseToNode('
+a: foo(1, 2, 3)
+');
+
+$traverser = new Neon\Traverser;
+$node = $traverser->traverse($node, $visitor);
+$value = $node->toValue();
+
+Assert::equal([
+	'a' => new Nette\Neon\Entity(
+		'foo',
+		['key0' => 1, 'key1' => 2, 'key2' => 3]
+	),
+], $value);