What are functional-programming ways of implementing Conway's Game of Life
- by George Mauer
I recently implemented for fun Conway's Game of Life in Javascript (actually coffeescript but same thing). Since javascript can be used as a functional language I was trying to stay to that end of the spectrum. I was not happy with my results. I am a fairly good OO programmer and my solution smacked of same-old-same-old. So long question short: what is the (pseudocode) functional style of doing it?
Here is Pseudocode for my attempt:
class Node
update: (board) ->
get number_of_alive_neighbors from board
get this_is_alive from board
if this_is_alive and number_of_alive_neighbors < 2 then die
if this_is_alive and number_of_alive_neighbors > 3 then die
if not this_is_alive and number_of_alive_neighbors == 3 then alive
class NodeLocations
at: (x, y) -> return node value at x,y
of: (node) -> return x,y of node
class Board
getNeighbors: (node) ->
use node_locations to check 8 neighbors
around node and return count
nodes = for 1..100 new Node
state = new NodeState(nodes)
locations = new NodeLocations(nodes)
board = new Board(locations, state)
executeRound:
state = clone state
accumulated_changes = for n in nodes n.update(board)
apply accumulated_changes to state
board = new Board(locations, state)
