Wolfram's 1D cellular automation in F# console

wolfram.fsx

(* 
	A simple F# script to display Wolfram's basic 1D cellular automaton rules as text output [1]
	
	-mg
*)

let runWolframRule rule cells  iterations =

    let compute cells ith rule =
        let withBorders = 0 :: cells @ [0];
        (withBorders.[ith], withBorders.[ith+1], withBorders.[ith+2])
                |> fun (a,b,c) -> 0 ||| (a <<< 2) ||| (b <<< 1) ||| (c <<< 0)
                |> fun bit -> if (rule &&& (1 <<< bit) <> 0 ) then 1 else 0

    let toStr cells =
        cells   |> List.map  (function | 0 -> '.' | 1 | _ -> '#')
                |> List.fold (sprintf "%s%c") ""

    let computeAndPrint cells =
        printfn "%s" <| toStr cells
        cells   |> List.mapi (fun i _ -> compute cells i rule)

    [0..iterations]
                |> List.fold (fun st _ -> computeAndPrint st) cells

let sampleCells x = (List.replicate x 0) @ [1] @ (List.replicate x 0)

(*
Here's a sample output:

runWolframRule 30 sampleCells 40

........................................#........................................

.......................................###.......................................

......................................##..#......................................

.....................................##.####.....................................

....................................##..#...#....................................

...................................##.####.###...................................

..................................##..#....#..#..................................

.................................##.####..######.................................

................................##..#...###.....#................................

...............................##.####.##..#...###...............................

..............................##..#....#.####.##..#..............................

.............................##.####..##.#....#.####.............................

............................##..#...###..##..##.#...#............................

...........................##.####.##..###.###..##.###...........................

..........................##..#....#.###...#..###..#..#..........................

.........................##.####..##.#..#.#####..#######.........................

........................##..#...###..####.#....###......#........................

.......................##.####.##..###....##..##..#....###.......................

......................##..#....#.###..#..##.###.####..##..#......................

.....................##.####..##.#..######..#...#...###.####.....................

....................##..#...###..####.....####.###.##...#...#....................

...................##.####.##..###...#...##....#...#.#.###.###...................

..................##..#....#.###..#.###.##.#..###.##.#.#...#..#..................

.................##.####..##.#..###.#...#..####...#..#.##.######.................

................##..#...###..####...##.#####...#.#####.#..#.....#................

...............##.####.##..###...#.##..#....#.##.#.....#####...###...............

..............##..#....#.###..#.##.#.####..##.#..##...##....#.##..#..............

.............##.####..##.#..###.#..#.#...###..####.#.##.#..##.#.####.............

............##..#...###..####...####.##.##..###....#.#..####..#.#...#............

...........##.####.##..###...#.##....#..#.###..#..##.####...###.##.###...........

..........##..#....#.###..#.##.#.#..#####.#..######..#...#.##...#..#..#..........

.........##.####..##.#..###.#..#.####.....####.....####.##.#.#.#########.........

........##..#...###..####...####.#...#...##...#...##....#..#.#.#........#........

.......##.####.##..###...#.##....##.###.##.#.###.##.#..#####.#.##......###.......

......##..#....#.###..#.##.#.#..##..#...#..#.#...#..####.....#.#.#....##..#......

.....##.####..##.#..###.#..#.####.####.#####.##.#####...#...##.#.##..##.####.....

....##..#...###..####...####.#....#....#.....#..#....#.###.##..#.#.###..#...#....

...##.####.##..###...#.##....##..###..###...######..##.#...#.###.#.#..####.###...

..##..#....#.###..#.##.#.#..##.###..###..#.##.....###..##.##.#...#.####....#..#..

.##.####..##.#..###.#..#.####..#..###..###.#.#...##..###..#..##.##.#...#..######.

##..#...###..####...####.#...######..###...#.##.##.###..######..#..##.#####.....#

[1] http://en.wikipedia.org/wiki/Wolfram_code

*)