Add a new Importer nikic/php-ast.

Author: drupol

README.md

@@ -34,6 +34,9 @@ Exporters and importers:
 * **Graph**: Export a tree into a Graph using the [graphp/graphp](https://github.com/graphp/graph) library.
 * **GraphViz**: Export a tree into a script in [GraphViz](http://www.graphviz.org/) format.
 * **Text**: Export a tree into a simple string, easy for storing in a database.
+* **nikic/php-ast**: Import a tree from an AST generated by the PHP extension [AST](https://github.com/nikic/php-ast).
+* **nikic/php-parser**: Import a tree from an AST generated by [nikic/php-parser](https://github.com/nikic/php-parser).
+* **microsoft/tolerant-php-parser**: Import a tree from an AST generated by [microsoft/tolerant-php-parser](https://github.com/microsoft/tolerant-php-parser).
 
 Modifier:
 * **Reverse**: To reverse a tree, all the children are mirrored.

spec/loophp/phptree/Importer/NikicPhpAstSpec.php

@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types=1);
+
+namespace spec\loophp\phptree\Importer;
+
+use loophp\phptree\Importer\NikicPhpAst;
+use loophp\phptree\Node\AttributeNodeInterface;
+use PhpSpec\ObjectBehavior;
+
+class NikicPhpAstSpec extends ObjectBehavior
+{
+    public function it_can_import(): void
+    {
+        $file = __DIR__ . '/../../../../src/Node/Node.php';
+        $ast = \ast\parse_file($file, 50);
+
+        $this
+            ->import($ast)
+            ->shouldImplement(AttributeNodeInterface::class);
+
+        $this
+            ->import($ast)
+            ->count()
+            ->shouldReturn(542);
+
+        $file = __DIR__ . '/../../../../tests/sample.php';
+        $ast = \ast\parse_file($file, 50);
+
+        $this
+            ->import($ast)
+            ->count()
+            ->shouldReturn(84);
+    }
+
+    public function it_is_initializable(): void
+    {
+        $this->shouldHaveType(NikicPhpAst::class);
+    }
+}

src/Importer/NikicPhpAst.php

@@ -0,0 +1,74 @@
+<?php
+
+declare(strict_types=1);
+
+namespace loophp\phptree\Importer;
+
+use ast\Node;
+use Exception;
+use loophp\phptree\Node\AttributeNode;
+use loophp\phptree\Node\AttributeNodeInterface;
+use loophp\phptree\Node\NodeInterface;
+
+use function ast\get_metadata;
+
+/**
+ * Class NikicPhpAst.
+ */
+final class NikicPhpAst implements ImporterInterface
+{
+    /**
+     * @var array<int, \ast\Metadata>
+     */
+    private $metadata;
+
+    /**
+     * @param Node $data
+     *
+     * @throws Exception
+     *
+     * @return \loophp\phptree\Node\NodeInterface
+     */
+    public function import($data): NodeInterface
+    {
+        $this->metadata = get_metadata();
+
+        return $this->parseNode($this->createNode(['label' => 'root']), $data);
+    }
+
+    /**
+     * @param array $attributes
+     *
+     * @return \loophp\phptree\Node\AttributeNodeInterface
+     */
+    private function createNode(array $attributes): AttributeNodeInterface
+    {
+        return new AttributeNode($attributes);
+    }
+
+    /**
+     * @param \loophp\phptree\Node\AttributeNodeInterface $parent
+     * @param Node ...$astNodes
+     *
+     * @return \loophp\phptree\Node\NodeInterface
+     */
+    private function parseNode(AttributeNodeInterface $parent, Node ...$astNodes): NodeInterface
+    {
+        return array_reduce(
+            $astNodes,
+            function (AttributeNodeInterface $carry, Node $astNode): NodeInterface {
+                return $carry
+                    ->add(
+                        $this->parseNode(
+                            $this->createNode([
+                                'label' => $this->metadata[$astNode->kind]->name,
+                                'astNode' => $astNode,
+                            ]),
+                            ...array_values(array_filter($astNode->children, 'is_object'))
+                        )
+                    );
+            },
+            $parent
+        );
+    }
+}