A purely functional, typechecked Lisp written in Haskell.
(define ((fib int) (x int))
  (+.i (fib (-.i x 1) (-.i x 2))))
(define ((elem? bool) (x any) (xs list))
  (cond ((null? xs) false)
	((eq? (car xs) x) true)
	(true (elem? x (cdr xs)))))Build and run using Stack.
$ stack build
$ stack run script.lisp # run a script
$ stack run -- -r       # repl- Actual closures
 - IO capabilities
 - Tail-call optimization
 - General optimization