RosettaCodeData/Task/Langtons-ant/CoffeeScript/langtons-ant-1.coffee

80 lines
1.9 KiB
CoffeeScript

class Ant
constructor: (@world) ->
@location = [0, 0]
@direction = 'E'
move: =>
[x, y] = @location
if @world.is_set x, y
@world.unset x, y
@direction = Directions.left @direction
else
@world.set x, y
@direction = Directions.right @direction
@location = Directions.forward(x, y, @direction)
# Model a theoretically infinite 2D world with a hash, allowing squares
# to be black or white (independent of any ants.)
class BlackWhiteWorld
constructor: ->
@bits = {}
set: (x, y) ->
@bits["#{x},#{y}"] = true
unset: (x, y) ->
delete @bits["#{x},#{y}"]
is_set: (x, y) ->
@bits["#{x},#{y}"]
draw: ->
# Most of this code just involves finding the extent of the world.
# Always include the origin, even if it's not set.
@min_x = @max_x = @min_y = @max_y = 0
for key of @bits
[xx, yy] = (coord for coord in key.split ',')
x = parseInt xx
y = parseInt yy
@min_x = x if x < @min_x
@max_x = x if x > @max_x
@min_y = y if y < @min_y
@max_y = y if y > @max_y
console.log "top left: #{@min_x}, #{@max_y}, bottom right: #{@max_x}, #{@min_y}"
for y in [@max_y..@min_y] by -1
s = ''
for x in [@min_x..@max_x]
if @bits["#{x},#{y}"]
s += '#'
else
s += '_'
console.log s
# Simple code for directions, independent of ants.
Directions =
left: (dir) ->
return 'W' if dir == 'N'
return 'S' if dir == 'W'
return 'E' if dir == 'S'
'N'
right: (dir) ->
return 'E' if dir == 'N'
return 'S' if dir == 'E'
return 'W' if dir == 'S'
'N'
forward: (x, y, dir) ->
return [x, y+1] if dir == 'N'
return [x, y-1] if dir == 'S'
return [x+1, y] if dir == 'E'
return [x-1, y] if dir == 'W'
world = new BlackWhiteWorld()
ant = new Ant(world)
for i in [1..11500]
ant.move()
console.log "Ant is at #{ant.location}, direction #{ant.direction}"
world.draw()