Data update

Task/Anonymous-recursion/Crystal/anonymous-recursion.cr

@@ -0,0 +1,14 @@
+def fib (n : Int64)
+  raise "only positive numbers allowed" if n < 0
+  # it needs to be declared beforehand to be able to call it
+  # from inside itself
+  fib1 = uninitialized Int64 -> Int64
+  fib1 = -> (n : Int64) {
+    if n < 2
+      n
+    else
+      fib1[n - 1] + fib1[n - 2]
+    end
+  }
+  fib1[n]
+end