;;; Test case for disjoint-set library
;;; written by Peter Lane, 2010

(require-extension disjoint-set) 
(require-extension srfi-78)
(require-extension srfi-13)

(check-set-mode! 'summary)

(let ((eg1 (make-disjoint-set string-hash string=?))
      (item1 "a")
      (item2 "b")
      (item3 "c"))
  ;; check error on looking for nonexistent item
  (check (disjoint-set:find eg1 item1) => 'item-not-found)
  ;; add the three items
  (disjoint-set:make eg1 item1)
  (disjoint-set:make eg1 item2)
  (disjoint-set:make eg1 item3)
  ;; check all three give different references
  (let ((ref1 (disjoint-set:find eg1 item1))
        (ref2 (disjoint-set:find eg1 item2))
        (ref3 (disjoint-set:find eg1 item3)))
    (check (eq? ref1 ref2) => #f)
    (check (eq? ref2 ref3) => #f)
    (check (eq? ref3 ref1) => #f))
  ;; merge one and two
  (disjoint-set:union eg1 (disjoint-set:find eg1 item1) (disjoint-set:find eg1 item2))
  (let ((ref1 (disjoint-set:find eg1 item1))
        (ref2 (disjoint-set:find eg1 item2))
        (ref3 (disjoint-set:find eg1 item3)))
    (check (eq? ref1 ref2) => #t)
    (check (eq? ref2 ref3) => #f)
    (check (eq? ref3 ref1) => #f))
  ;; merge one and three
  (disjoint-set:union eg1 (disjoint-set:find eg1 item1) (disjoint-set:find eg1 item3))
  (let ((ref1 (disjoint-set:find eg1 item1))
        (ref2 (disjoint-set:find eg1 item2))
        (ref3 (disjoint-set:find eg1 item3)))
    (check (eq? ref1 ref2) => #t)
    (check (eq? ref2 ref3) => #t)
    (check (eq? ref3 ref1) => #t)))

(if (check-passed? 10)
  'ok
  (error "Failed test suite"))