--
--
-- Mah-jong example
--
--

--
-- Matcher definitions
--
suit :=
  algebraicDataMatcher
    | wan
    | pin
    | sou

honor :=
  algebraicDataMatcher
    | ton
    | nan
    | sha
    | pe
    | haku
    | hatsu
    | chun

tile :=
  algebraicDataMatcher
    | num suit integer
    | hnr honor

--
-- Pattern modularization
--
twin := \pat1 pat2 => ($pat & ~pat1) :: #pat :: ~pat2

shuntsu :=
  \pat1 pat2 =>
    (num $s $n & ~pat1) :: num #s #(n + 1) :: num #s #(n + 2) :: ~pat2

kohtsu := \pat1 pat2 => ($pat & ~pat1) :: #pat :: #pat :: ~pat2

--
-- A function that determines whether the hand is completed or not.
--
complete? :=
  \match as multiset tile with
    | twin
        $th_1
        (shuntsu $sh_1
           (shuntsu $sh_2
              (shuntsu $sh_3 (shuntsu $sh_4 [] | kohtsu $kh_1 [])
              | kohtsu $kh_1 (kohtsu $kh_2 []))
           | kohtsu $kh_1 (kohtsu $kh_2 (kohtsu $kh_3 [])))
        | kohtsu $kh_1 (kohtsu $kh_2 (kohtsu $kh_3 (kohtsu $kh_4 []))))
        (twin $th_2 (twin $th_3 (twin $th_4 (twin $th_5 (twin $th_6 (twin $th_7 []))))))
    -> True
    | _ -> False

--
-- Demonstration code
--
assertEqual "mahjong 1"
  (complete?
     [ Hnr Haku,  Hnr Haku
     , Num Wan 3, Num Wan 4, Num Wan 5
     , Num Wan 6, Num Wan 7, Num Wan 8
     , Num Pin 2, Num Pin 3, Num Pin 4
     , Num Sou 6, Num Sou 6, Num Sou 6 ])
  True

assertEqual "mahjong 2"
  (complete?
     [ Hnr Haku,  Hnr Haku
     , Num Pin 1, Num Pin 3, Num Pin 4
     , Num Wan 6, Num Wan 7, Num Wan 8
     , Num Wan 3, Num Wan 4, Num Wan 5
     , Num Sou 6, Num Sou 6, Num Sou 6 ])
  False