update

Task/Anonymous-recursion/PHP/anonymous-recursion-3.php

@@ -0,0 +1,18 @@
+<?php
+class fib_helper {
+    function __invoke($n) {
+        if ($n < 2)
+            return 1;
+        else
+            return $this($n-1) + $this($n-2);
+    }
+}
+
+function fib($n) {
+    if ($n < 0)
+        throw new Exception('Negative numbers not allowed');
+    $f = new fib_helper();
+    return $f($n);
+}
+echo fib(8), "\n";
+?>