Primo Committ

vendor/league/commonmark/src/Node/NodeWalker.php

@@ -0,0 +1,89 @@
+<?php
+
+/*
+ * This file is part of the league/commonmark package.
+ *
+ * (c) Colin O'Dell <colinodell@gmail.com>
+ *
+ * Original code based on the CommonMark JS reference parser (https://bitly.com/commonmark-js)
+ *  - (c) John MacFarlane
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace League\CommonMark\Node;
+
+final class NodeWalker
+{
+    /**
+     * @var Node
+     */
+    private $root;
+
+    /**
+     * @var Node|null
+     */
+    private $current;
+
+    /**
+     * @var bool
+     */
+    private $entering;
+
+    public function __construct(Node $root)
+    {
+        $this->root = $root;
+        $this->current = $this->root;
+        $this->entering = true;
+    }
+
+    /**
+     * Returns an event which contains node and entering flag
+     * (entering is true when we enter a Node from a parent or sibling,
+     * and false when we reenter it from child)
+     *
+     * @return NodeWalkerEvent|null
+     */
+    public function next(): ?NodeWalkerEvent
+    {
+        $current = $this->current;
+        $entering = $this->entering;
+        if (null === $current) {
+            return null;
+        }
+
+        if ($entering && $current->isContainer()) {
+            if ($current->firstChild()) {
+                $this->current = $current->firstChild();
+                $this->entering = true;
+            } else {
+                $this->entering = false;
+            }
+        } elseif ($current === $this->root) {
+            $this->current = null;
+        } elseif (null === $current->next()) {
+            $this->current = $current->parent();
+            $this->entering = false;
+        } else {
+            $this->current = $current->next();
+            $this->entering = true;
+        }
+
+        return new NodeWalkerEvent($current, $entering);
+    }
+
+    /**
+     * Resets the iterator to resume at the specified node
+     *
+     * @param Node $node
+     * @param bool $entering
+     *
+     * @return void
+     */
+    public function resumeAt(Node $node, bool $entering = true)
+    {
+        $this->current = $node;
+        $this->entering = $entering;
+    }
+}