io.kvs

(extern malloc (-> UInt (Ptr UInt8)))
(extern read_int64 (-> RealWorld (Cons Int64 RealWorld)))
(extern print_int64 (-> (Cons Int64 RealWorld) (Cons Nil RealWorld)))
(extern print_float64 (-> (Cons Float64 RealWorld) (Cons Nil RealWorld)))

(extern eq-int64 (-> (Cons Int64 Int64) Bool))
(extern lt-int64 (-> (Cons Int64 Int64) Bool))
(extern gt-int64 (-> (Cons Int64 Int64) Bool))
(extern mul-int64 (-> (Cons Int64 Int64) Int64))
(extern div-int64 (-> (Cons Int64 Int64) Int64))
(extern add-int64 (-> (Cons Int64 Int64) Int64))
(extern sub-int64 (-> (Cons Int64 Int64) Int64))

(define (= x y) (eq-int64 (cons x y)))
(define (< x y) (lt-int64 (cons x y)))
(define (> x y) (gt-int64 (cons x y)))
(define (* x y) (mul-int64 (cons x y)))
(define (/ x y) (div-int64 (cons x y)))
(define (+ x y) (add-int64 (cons x y)))
(define (- x y) (sub-int64 (cons x y)))

(define read-int64 read_int64)

(define (print-int64 x)
  (lambda (real-world)
    (print_int64 (cons x real-world))))

(define (>> io1 io2)
  (lambda (real-world)
    (io2 (cdr (io1 real-world)))))

(define (>>= io f)
  (lambda (real-world)
    (let ((r (io real-world))
          (v (car r))
          (real-world2 (cdr r)))
      (f v real-world2))))

(define (iomap io f)
  (lambda (real-world)
    (let ((r (io real-world))
          (v (car r))
          (real-world2 (cdr r)))
      (cons (f v) real-world2))))

(define (fib n)
  (let (((iter a b i)
         (if (= i 0)
             a
             (iter b (+ a b) (- i 1)))))
    (iter 0 1 n)))

(define main (>> (print-int64 1111111111)
                 (>>= (iomap read-int64 fib)
                      print-int64)))