33 lines
847 B
Haskell
33 lines
847 B
Haskell
{-# LANGUAGE ScopedTypeVariables #-}
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{-# LANGUAGE TypeApplications #-}
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module GOL.Engine where
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import Control.Comonad.Env
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import Control.Comonad.Representable.Store
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import Data.Bool (bool)
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import GOL.Rule
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import GOL.Space
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-- | The comonad stack used in the Game of Life engine.
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-- It consists of a store comonad over the space @f@,
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-- with an environment containing a rule.
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type GOL f = EnvT Rule (Store f)
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getNeighbors :: forall f a. Space f => GOL f a -> [a]
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getNeighbors = experiment $ neighbors @f
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nextState :: Space f => GOL f Bool -> Bool
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nextState = do
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neighborStates <- getNeighbors
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let count = sum . fmap (bool 0 1) $ neighborStates
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selfState <- extract
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Rule survive birth <- ask
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return $
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if selfState
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then survive count
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else birth count
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tick :: Space f => GOL f Bool -> GOL f Bool
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tick = extend nextState |