Let Modifiers use a customizable traverser.

Author: drupol

src/Modifier/Apply.php

@@ -5,6 +5,8 @@
 namespace loophp\phptree\Modifier;
 
 use loophp\phptree\Node\NodeInterface;
+use loophp\phptree\Traverser\PostOrder;
+use loophp\phptree\Traverser\TraverserInterface;
 
 /**
  * Class Apply.
@@ -17,22 +19,28 @@ class Apply implements ModifierInterface
     private $apply;
 
     /**
-     * Filter constructor.
+     * @var \loophp\phptree\Traverser\TraverserInterface|null
+     */
+    private $traverser;
+
+    /**
+     * Apply constructor.
      *
      * @param callable $apply
+     * @param \loophp\phptree\Traverser\TraverserInterface|null $traverser
      */
-    public function __construct(callable $apply)
+    public function __construct(callable $apply, ?TraverserInterface $traverser = null)
     {
         $this->apply = $apply;
+        $this->traverser = $traverser ?? new PostOrder();
     }
 
     /**
      * {@inheritdoc}
      */
     public function modify(NodeInterface $tree): NodeInterface
     {
-        /** @var \loophp\phptree\Node\MerkleNode $item */
-        foreach ($tree->all() as $item) {
+        foreach ($this->traverser->traverse($tree) as $item) {
             ($this->apply)($item);
         }
 

src/Modifier/Filter.php

@@ -5,6 +5,8 @@
 namespace loophp\phptree\Modifier;
 
 use loophp\phptree\Node\NodeInterface;
+use loophp\phptree\Traverser\PostOrder;
+use loophp\phptree\Traverser\TraverserInterface;
 
 /**
  * Class Filter.
@@ -16,23 +18,29 @@ class Filter implements ModifierInterface
      */
     private $filter;
 
+    /**
+     * @var \loophp\phptree\Traverser\PreOrder|\loophp\phptree\Traverser\TraverserInterface
+     */
+    private $traverser;
+
     /**
      * Filter constructor.
      *
      * @param callable $filter
+     * @param \loophp\phptree\Traverser\TraverserInterface|null $traverser
      */
-    public function __construct(callable $filter)
+    public function __construct(callable $filter, ?TraverserInterface $traverser = null)
     {
         $this->filter = $filter;
+        $this->traverser = $traverser ?? new PostOrder();
     }
 
     /**
      * {@inheritdoc}
      */
     public function modify(NodeInterface $tree): NodeInterface
     {
-        /** @var \loophp\phptree\Node\MerkleNode $item */
-        foreach ($tree->all() as $item) {
+        foreach ($this->traverser->traverse($tree) as $item) {
             if (null === $parent = $item->getParent()) {
                 continue;
             }

src/Modifier/FulfillCapacity.php

@@ -5,19 +5,36 @@
 namespace loophp\phptree\Modifier;
 
 use loophp\phptree\Node\NodeInterface;
+use loophp\phptree\Traverser\PostOrder;
+use loophp\phptree\Traverser\TraverserInterface;
 
 /**
  * Class FulfillCapacity.
  */
 class FulfillCapacity implements ModifierInterface
 {
+    /**
+     * @var \loophp\phptree\Traverser\PreOrder|\loophp\phptree\Traverser\TraverserInterface
+     */
+    private $traverser;
+
+    /**
+     * FulfillCapacity constructor.
+     *
+     * @param \loophp\phptree\Traverser\TraverserInterface|null $traverser
+     */
+    public function __construct(?TraverserInterface $traverser = null)
+    {
+        $this->traverser = $traverser ?? new PostOrder();
+    }
+
     /**
      * {@inheritdoc}
      */
     public function modify(NodeInterface $tree): NodeInterface
     {
-        /** @var \loophp\phptree\Node\MerkleNode $item */
-        foreach ($tree->all() as $item) {
+        /** @var \loophp\phptree\Node\NaryNodeInterface $item */
+        foreach ($this->traverser->traverse($tree) as $item) {
             $capacity = $item->capacity();
 
             if (false === $item->isLeaf()) {

src/Modifier/RemoveNullNode.php

@@ -5,24 +5,41 @@
 namespace loophp\phptree\Modifier;
 
 use loophp\phptree\Node\NodeInterface;
+use loophp\phptree\Traverser\PostOrder;
+use loophp\phptree\Traverser\TraverserInterface;
 
 /**
  * Class RemoveNullNode.
  */
 class RemoveNullNode implements ModifierInterface
 {
+    /**
+     * @var \loophp\phptree\Traverser\PreOrder|\loophp\phptree\Traverser\TraverserInterface
+     */
+    private $traverser;
+
+    /**
+     * RemoveNullNode constructor.
+     *
+     * @param \loophp\phptree\Traverser\TraverserInterface|null $traverser
+     */
+    public function __construct(?TraverserInterface $traverser = null)
+    {
+        $this->traverser = $traverser ?? new PostOrder();
+    }
+
     /**
      * {@inheritdoc}
      */
     public function modify(NodeInterface $tree): NodeInterface
     {
-        /** @var \loophp\phptree\Node\MerkleNode $item */
-        foreach ($tree->all() as $item) {
+        /** @var \loophp\phptree\Node\ValueNodeInterface $item */
+        foreach ($this->traverser->traverse($tree) as $item) {
             if (null === $parent = $item->getParent()) {
                 continue;
             }
 
-            if (true !== $item->isLeaf()) {
+            if (false === $item->isLeaf()) {
                 continue;
             }