cellular-automata

cellular-automata is a flexible library for the simulation of cellular automata (henceforth CA/CAs). It is based around a new typeclass which can represent cellular automata with arbitrary topologies (introduced here). It also contains some data types for various kinds of CA universes, as well as several utility functions.

Examples

The examples below can be run by calling evolve _selectedRule _myUniverse; this will evolve _myUniverse by one generation according to the selected rule.

-- Conway's Game of Life. (Included in the CA.Utils module)
conwayLife :: CARule Point Bool
-- Note the type signature above: it states that conwayLife operates
-- on universes which use 2D points ('Point'), with state type 'Bool'.
conwayLife curPoint curUniverse =
    case (peek curPoint curUniverse) of
        False -> if surrounds == 3          then True else False
        True  -> if surrounds `elem` [2, 3] then True else False
  where
    -- The number of surrounding 'True' cells
    surrounds = count id $
        fmap (`peek` cur_universe) $ moore False curPoint

-- Wolfram's Rule 30
rule30 :: CARule Int Bool
-- Again, the type signature states that rule30 operates on universes
-- which use 1D points ('Int'), with state type 'Bool'.
rule30 curPoint curUniverse =
    let left  = peek (p-1) s
        mid   = peek  p    s
        right = peek (p+1) s
    in
        (    left && not mid && not right)
     || (not left &&     mid &&     right)
     || (not left &&     mid && not right)
     || (not left && not mid &&     right)