The Wolfram 2, 3 Turing Machine in CoffeeScript

main.coffee

logTm = (tm) ->
  text = tm.colors
    .map (s, i) -> if i is tm.pos then "%c" + ["▲", "▼"][tm.state] else "%c　"
    .join ""
  style = tm.colors.map (c) -> "background-color:" + ["white", "yellow", "orange"][c] + ";"
  console.log.apply console, [text].concat style

# [state, color] = [state, color, offset]
rule = {}
rule[[0, 2]] = [0, 1, -1]
rule[[0, 1]] = [0, 2, -1]
rule[[0, 0]] = [1, 1, 1] 
rule[[1, 2]] = [0, 0, 1]
rule[[1, 1]] = [1, 2, 1] 
rule[[1, 0]] = [0, 2, -1]

stepTm = (tm) ->
  r = rule[[tm.state, tm.colors[tm.pos]]]
  tm.state = r[0]
  tm.colors[tm.pos] = r[1]
  tm.pos += r[2]

tm =
  colors: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
  pos: 3
  state: 0

for _ in [0..50]
  logTm tm
  stepTm tm

Result