;; lib/minikanren/tests/clpfd-ord.sx — fd-lt / fd-lte / fd-eq.

;; --- fd-lt ---

(mk-test
  "fd-lt-narrows-x-against-num"
  (run*
    q
    (fresh
      (x)
      (fd-in x (list 1 2 3 4 5))
      (fd-lt x 3)
      (fd-label (list x))
      (== q x)))
  (list 1 2))

(mk-test
  "fd-lt-narrows-x-against-num-symmetric"
  (run*
    q
    (fresh
      (x)
      (fd-in x (list 1 2 3 4 5))
      (fd-lt 3 x)
      (fd-label (list x))
      (== q x)))
  (list 4 5))

(mk-test
  "fd-lt-pair-ordered"
  (let
    ((res (run* q (fresh (x y) (fd-in x (list 1 2 3 4)) (fd-in y (list 1 2 3 4)) (fd-lt x y) (fd-label (list x y)) (== q (list x y))))))
    (= (len res) 6))
  true)

(mk-test
  "fd-lt-impossible-fails"
  (run*
    q
    (fresh
      (x)
      (fd-in x (list 5 6 7))
      (fd-lt x 3)
      (fd-label (list x))
      (== q x)))
  (list))

;; --- fd-lte ---

(mk-test
  "fd-lte-includes-equal"
  (run*
    q
    (fresh
      (x)
      (fd-in x (list 1 2 3 4 5))
      (fd-lte x 3)
      (fd-label (list x))
      (== q x)))
  (list 1 2 3))

(mk-test
  "fd-lte-equal-bound"
  (run*
    q
    (fresh
      (x)
      (fd-in x (list 1 2 3 4 5))
      (fd-lte 3 x)
      (fd-label (list x))
      (== q x)))
  (list 3 4 5))

;; --- fd-eq ---

(mk-test
  "fd-eq-bind"
  (run*
    q
    (fresh
      (x)
      (fd-in x (list 1 2 3 4 5))
      (fd-eq x 3)
      (== q x)))
  (list 3))

(mk-test
  "fd-eq-out-of-domain-fails"
  (run*
    q
    (fresh
      (x)
      (fd-in x (list 1 2 3))
      (fd-eq x 5)
      (== q x)))
  (list))

(mk-test
  "fd-eq-two-vars-share-domain"
  (run*
    q
    (fresh
      (x y)
      (fd-in x (list 1 2 3))
      (fd-in y (list 2 3 4))
      (fd-eq x y)
      (fd-label (list x y))
      (== q (list x y))))
  (list (list 2 2) (list 3 3)))

;; --- combine fd-lt + fd-neq for "between" puzzle ---

(mk-test
  "fd-lt-neq-combined"
  (run*
    q
    (fresh
      (x y z)
      (fd-in x (list 1 2 3))
      (fd-in y (list 1 2 3))
      (fd-in z (list 1 2 3))
      (fd-lt x y)
      (fd-lt y z)
      (fd-label (list x y z))
      (== q (list x y z))))
  (list (list 1 2 3)))

(mk-tests-run!)