Implement abstract class EnumeratingFilterIterator

library/Icinga/Util/EnumeratingFilterIterator.php

@@ -0,0 +1,37 @@
+<?php
+// {{{ICINGA_LICENSE_HEADER}}}
+// {{{ICINGA_LICENSE_HEADER}}}
+
+namespace Icinga\Util;
+
+use FilterIterator;
+
+/**
+ * Class EnumeratingFilterIterator
+ *
+ * FilterIterator with continuous numeric key (index)
+ */
+abstract class EnumeratingFilterIterator extends FilterIterator
+{
+    /**
+     * @var int
+     */
+    private $index;
+
+    /**
+     * @return void
+     */
+    public function rewind()
+    {
+        parent::rewind();
+        $this->index = 0;
+    }
+
+    /**
+     * @return int
+     */
+    public function key()
+    {
+        return $this->index++;
+    }
+}