28 lines
928 B
Haskell
28 lines
928 B
Haskell
{-# LANGUAGE AllowAmbiguousTypes #-}
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{-# LANGUAGE FlexibleContexts #-}
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{-# LANGUAGE TypeFamilies #-}
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module GOL.Space where
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import Data.Functor.Rep
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-- | A space in which a Conway's Game of Life simulation
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-- takes place, with a notion of "neighbors to a cell" defined.
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--
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-- More specifically, a space is a representable functor @f@ such
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-- that @'Rep' f@ is a graph. 'neighbors' then takes a node of
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-- that graph and returns all nodes that are adjacent.
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--
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-- Instances should satisfy:
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--
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-- * Symmetry: if @x '`elem`' 'neighbors' y@, then @y '`elem`' 'neighbors' x@.
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--
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-- * Irreflexivity: @x '`elem`' 'neighbors' x@ is always false.
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class Representable f => Space f where
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neighbors :: Rep f -> [Rep f]
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-- | A space is _displayable_ if it is representable over a 2D
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-- grid. The graphical system requires a displayable space.
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class (Space f, Rep f ~ (Int, Int)) => DisplayableSpace f where
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sizex :: Int
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sizey :: Int |