codepad

Language:

; three farmers

(define-syntax fold-of
  (syntax-rules (range in is)
    ((_ "z" f b e) (set! b (f b e)))
    ((_ "z" f b e (v range fst pst stp) c ...)
      (let* ((x fst) (p pst) (s stp)
             (le? (if (positive? s) <= >=)))
        (do ((v x (+ v s))) ((le? p v) b)
          (fold-of "z" f b e c ...))))
    ((_ "z" f b e (v range fst pst) c ...)
      (let* ((x fst) (p pst) (s (if (< x p) 1 -1)))
        (fold-of "z" f b e (v range x p s) c ...)))
    ((_ "z" f b e (v range pst) c ...)
      (fold-of "z" f b e (v range 0 pst) c ...))
    ((_ "z" f b e (x in xs) c ...)
      (do ((t xs (cdr t))) ((null? t) b)
        (let ((x (car t)))
          (fold-of "z" f b e c ...))))
    ((_ "z" f b e (x is y) c ...)
      (let ((x y)) (fold-of "z" f b e c ...)))
    ((_ "z" f b e p? c ...)
      (if p? (fold-of "z" f b e c ...)))
    ((_ f i e c ...)
      (let ((b i)) (fold-of "z" f b e c ...)))))

(define-syntax list-of (syntax-rules ()
  ((_ arg ...) (reverse (fold-of
    (lambda (d a) (cons a d)) '() arg ...)))))

(display
  (list-of (list am pm first second third)
    (c range 1 52) (pm range 1 202)
    (zero? (modulo (- 10500 (* (- 52 c) pm)) c))
    (am is (quotient (- 10500 (* (- 52 c) pm)) c))
    (zero? (modulo (- 3500 (* 10 pm)) (- am pm)))
    (zero? (modulo (- 3500 (* 16 pm)) (- am pm)))
    (zero? (modulo (- 3500 (* 26 pm)) (- am pm)))
    (first is (quotient (- 3500 (* 10 pm)) (- am pm)))
    (second is (quotient (- 3500 (* 16 pm)) (- am pm)))
    (third is (quotient (- 3500 (* 26 pm)) (- am pm)))
    (<= 0 first 10) (<= 0 second 16) (<= 0 third 26)))

Private [?]

Run code