Merge pull request #3 from drupol/trie-trees

Implements a new tree type: Trie

spec/drupol/phptree/Node/TrieNodeSpec.php

@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace spec\drupol\phptree\Node;
+
+use drupol\phptree\Node\KeyValueNode;
+use drupol\phptree\Node\TrieNode;
+use PhpSpec\ObjectBehavior;
+
+class TrieNodeSpec extends ObjectBehavior
+{
+    public function it_is_initializable()
+    {
+        $this->shouldHaveType(TrieNode::class);
+    }
+
+    public function it_can_add_node()
+    {
+        $this->beConstructedWith('root', 'root');
+
+        $nodes = [
+            'ab',
+            'abc',
+            'abcd',
+            'abcde',
+            'cb',
+            'cba',
+            'dcba',
+            'edcba',
+        ];
+
+        foreach ($nodes as $key => $value) {
+            $nodes[$key] = new KeyValueNode($key, $value);
+        }
+
+        $this
+            ->add(...$nodes)
+            ->count()
+            ->shouldReturn(25);
+    }
+}

src/Exporter/Graph.php

@@ -59,13 +59,7 @@ public function getTraverser(): TraverserInterface
     }
 
     /**
-     * Export a node into a Graph.
-     *
-     * @param \drupol\phptree\Node\ValueNodeInterface $node
-     *   The node.
-     *
-     * @return \Fhaculty\Graph\Graph
-     *   The graph.
+     * {@inheritdoc}
      */
     public function export(ValueNodeInterface $node): OriginalGraph
     {

src/Exporter/Text.php

@@ -12,13 +12,7 @@
 class Text implements ExporterInterface
 {
     /**
-     * Export the node in a string.
-     *
-     * @param \drupol\phptree\Node\ValueNodeInterface $node
-     *   The node.
-     *
-     * @return string
-     *   The string.
+     * {@inheritdoc}
      */
     public function export(ValueNodeInterface $node): string
     {

src/Node/TrieNode.php

@@ -0,0 +1,60 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace drupol\phptree\Node;
+
+/**
+ * Class TrieNode
+ */
+class TrieNode extends KeyValueNode
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function add(NodeInterface ...$nodes): NodeInterface
+    {
+        foreach ($nodes as $node) {
+            $data = $node->getValue();
+
+            $hash = \hash('sha256', $node->getKey() . $data);
+
+            $node = new TrieNode($hash, \substr($data, 0, 1));
+            $parent = $this->append($node);
+
+            $dataWithoutFirstLetter = \substr($data, 1);
+            if (!empty($dataWithoutFirstLetter)) {
+                $parent->add(new TrieNode($hash, $dataWithoutFirstLetter));
+            } else {
+                $nodes = [$node->getValue()];
+                foreach ($node->getAncestors() as $ancestor) {
+                    $nodes[] = $ancestor->getValue();
+                }
+                \array_pop($nodes);
+                $node->append(new TrieNode($hash, \strrev(\implode('', $nodes))));
+            }
+        }
+
+        return $this;
+    }
+
+    /**
+     * @param \drupol\phptree\Node\ValueNodeInterface $node
+     *
+     * @return \drupol\phptree\Node\NodeInterface|\drupol\phptree\Node\ValueNodeInterface
+     */
+    private function append(ValueNodeInterface $node)
+    {
+        /** @var \drupol\phptree\Node\ValueNodeInterface $child */
+        foreach ($this->children() as $child) {
+            /** @var \drupol\phptree\Node\ValueNodeInterface $node */
+            if ($node->getValue() === $child->getValue()) {
+                return $child;
+            }
+        }
+
+        parent::add($node);
+
+        return $node;
+    }
+}

tests/src/Exporter/KeyValueGraph.php

@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace drupol\phptree\tests\Exporter;
+
+use drupol\phptree\Node\NodeInterface;
+use Fhaculty\Graph\Vertex;
+
+/**
+ * Class KeyValueGraph
+ */
+class KeyValueGraph extends ValueGraph
+{
+    /**
+     * {@inheritdoc}
+     */
+    protected function createVertex(NodeInterface $node): Vertex
+    {
+        $vertex = parent::createVertex($node);
+
+        if (\method_exists($node, 'getValue') && \method_exists($node, 'getKey')) {
+            $vertex->setAttribute('graphviz.label', $node->getValue());
+        }
+
+        return $vertex;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function createVertexId(NodeInterface $node)
+    {
+        if (\method_exists($node, 'getValue') && \method_exists($node, 'getKey')) {
+            return $node->getKey() . $node->getValue();
+        }
+
+        return \sha1((string) parent::createVertexId($node));
+    }
+}