Data commit

Task/Anonymous-recursion/TXR/anonymous-recursion.txr

@@ -0,0 +1,16 @@
+(defmacro recursive ((. parm-init-pairs) . body)
+  (let ((hidden-name (gensym "RECURSIVE-")))
+    ^(macrolet ((recurse (. args) ^(,',hidden-name ,*args)))
+       (labels ((,hidden-name (,*[mapcar first parm-init-pairs]) ,*body))
+         (,hidden-name ,*[mapcar second parm-init-pairs])))))
+
+(defun fib (number)
+  (if (< number 0)
+    (error "Error. The number entered: ~a is negative" number)
+    (recursive ((n number) (a 0) (b 1))
+      (if (= n 0)
+        a
+        (recurse (- n 1) b (+ a b))))))
+
+(put-line `fib(10) = @(fib 10)`)
+(put-line `fib(-1) = @(fib -1)`))