Add and expose more useful functions on Hanafuda cards and use them in Yakus computations

src/Hanafuda.hs

@@ -5,8 +5,10 @@ module Hanafuda (
     , Pack
     , add
     , cards
+    , cardsOf
     , cardsOfPack
     , contains
+    , difference
     , empty
     , flower
     , intersection
@@ -16,6 +18,7 @@ module Hanafuda (
     , sameMonth
     , shuffle
     , size
+    , union
   ) where
 
 import Data.Word (Word64)
@@ -27,6 +30,7 @@ import Data.Bits (
     , testBit
     , xor
     , (.&.)
+    , (.|.)
     , countTrailingZeros
   )
 import System.Random (randomRIO)
@@ -112,6 +116,12 @@ intersection = portBinary (.&.)
 difference :: Pack -> Pack -> Pack
 difference = portBinary (\a b -> a `xor` (a .&. b))
 
+union :: Pack -> Pack -> Pack
+union = portBinary (.|.)
+
+cardsOf :: Flower -> Pack
+cardsOf = Pack . shift 0xf . (* 4) . fromEnum
+
 sameMonth :: Card -> Pack -> Pack
 sameMonth card (Pack p) = Pack $ (0xf `shift` (fromEnum card .&. 0xfc)) .&. p
 

src/Hanafuda/KoiKoi/Yaku.hs

@@ -6,11 +6,15 @@ module Hanafuda.KoiKoi.Yaku (
     , sumYakus
   ) where
 
-import Hanafuda (Card(..), Monthly, Pack, add, contains, intersection, packOfCards, size)
+import Hanafuda (
+      Card(..), Monthly, Pack
+    , add, cardsOf, cardsOfPack, contains, difference, intersection, packOfCards
+    , size
+  )
 import Hanafuda.Player (Points)
 import qualified Data.Map as M (Map, empty, insert, unionWith, (!))
 import qualified Data.Set as S (Set, empty, singleton, union)
-import Control.Monad.Reader (reader)
+import Control.Monad.Reader (asks)
 
 data Yaku =
     Lights
@@ -73,7 +77,7 @@ index (yaku, cards, scorer) =
 
 finders :: Monthly YakusByCard
 finders = do
-  monthCardPlus <- reader $ (+) . (4*) . fromEnum
+  monthCards <- cardsOfPack <$> asks cardsOf
   return $ foldl (\yakusByCard -> M.unionWith S.union yakusByCard . index) M.empty [
         (Lights, [Crane, CampCurtain, FullMoon, RainMan, Phoenix], lights)
       , (InoShikaCho, inoshikacho, fixed 5)
@@ -84,7 +88,7 @@ finders = do
       , (Kasu, plains, moreThan 9)
       , (TsukimiZake, [SakeCup, FullMoon], fixed 3)
       , (HanamiZake, [SakeCup, CampCurtain], fixed 3)
-      , (TsukiFuda, map (toEnum . monthCardPlus) [0..3], fixed 5)
+      , (TsukiFuda, monthCards, fixed 5)
     ]
   where
     inoshikacho = [Butterflies, Boar, Deer]