version: 1
name: Conway's Game of Life
author: Brent Yorgey
description: A basic implementation of the rules of the Game of Life.
robots:
  - name: base
    display:
      attr: robot
      char: 'Ω'
    loc: [0,0]
    dir: [1,0]
    devices:
      - treads
      - compass
      - grabber
      - clock
      - logger
    inventory:
      - [1000, rock]
  - name: cell
    system: true
    dir: [0,1]
    display:
      invisible: true
    inventory:
      - [1, rock]
    program: |
      def forever = \c. c; forever c; end;
      def cnt = \x.
        if (x == inl ()) {0} {1}
      end;
      def count3 =
        h <- scan down;
        f <- scan forward;
        b <- scan back;
        return (cnt h + cnt f + cnt b)
      end;
      def mod : int -> int -> int = \a. \b. a - (a/b)*b end;
      def waitUntil = \p.
        b <- p;
        if b {wait 1} {waitUntil p}
      end;
      forever (
        h <- scan down;
        alive <- return (h != inl ());
        n1 <- count3;
        turn left; move; turn right; n2 <- count3;
        turn right; move; move; turn left; n3 <- count3;
        turn left; move; turn right;
        total <- return (n1 + n2 + n3 - if alive {1} {0});
        if (alive && (total < 2 || total > 3))
          { grab; return () }
          { if (not alive && total == 3)
            { place "rock" }
            {}
          };
        // synchronize
        waitUntil (t <- time; return (mod t 0x20 == 0))
      )
world:
  default: [ice]
  palette:
    'o': [ice, rock, cell]
    '.': [ice, null, cell]
  upperleft: [1,-1]
  map: |
    ..............................
    ..............................
    ......o.......................
    .......o......................
    .....ooo......................
    ..............................
    ..............................
    ..............................
    ..............................
    ..............................
    ..............................
    ..............................
    ...............oooooooooo.....
    ..............................
    ..............................
    ..............................