59 lines
1.5 KiB
Haskell
59 lines
1.5 KiB
Haskell
module Format where
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import System.Random
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import State
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import Timestamp
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import Config
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currentFormat :: Timestamp -> State
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currentFormat t = strictApplyN n nextFormat initialRotation
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where
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n = t `monthsSince` genesis
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nextFormat :: State -> State
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nextFormat (p, b, r) = (np, nb, nr)
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where
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ip = rotateOld p
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(np, nr) = (addNewPack . addNewPack) (ip, r)
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nb = rotateBox b
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legalOutRot :: [OutRot] -> [OutRot]
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legalOutRot x = filter (\(Or _ n) -> n == 0) x
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updatePackAge :: [OutRot] -> [OutRot]
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updatePackAge p = map (\(Or s n) -> (Or s $ max 0 (n-1))) p
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setIllegal :: InRot -> OutRot
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setIllegal (Ir n) = Or n 3
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setLegal :: OutRot -> InRot
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setLegal (Or n _) = Ir n
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rotateOld :: Pool -> Pool
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rotateOld (i, o) = (ni, no)
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where
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ni = drop 2 i
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no = (updatePackAge o) ++ dropped
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dropped = map setIllegal (take 2 i)
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addNewPack :: (Pool, StdGen) -> (Pool, StdGen)
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addNewPack ((i, o), r) = ((ni, no), nr)
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where
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lp = length $ legalOutRot o
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(ip, nr) = randomR (0, lp-1) r
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np = (legalOutRot o) !! ip
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ni = i ++ [(setLegal np)]
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no = filter (\x -> x /= np) o
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rotate :: Integer -> [a] -> [a]
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rotate n xs = take lxs . drop ((fromIntegral n) `mod` lxs) . cycle $ xs
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where
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lxs = length xs
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rotateBox :: BoxQueue -> BoxQueue
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rotateBox (Bq x) = Bq $ rotate 1 x
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strictApplyN :: Integer -> (a -> a) -> a -> a
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strictApplyN 0 _ x = x
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strictApplyN n f x = strictApplyN (n - 1) f $! (f x)
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