life.rb

# Quick rendition of Conway's game of life
class Grid
  def initialize
    @width = 100
    @height = 30
    generate_grid
  end

  def generate_grid
    @grid = (0...@width).map do
      (0...@height).map do
        [0, 1].sample
      end
    end
  end

  def to_s
    (0...@height).map do |y|
      (0...@width).map do |x|
        [' ', '@'][@grid[x][y]]
      end.join
    end.join("\n")
  end

  def sibling_sum(x,y)
    [-1, 0, 1].flat_map do |offset_x|
      [-1, 0, 1].map do |offset_y|
        if (offset_x == 0 && offset_y == 0) || outside_grid?(x+offset_x,y+offset_y)
          0
        else
          raise "#{x}, #{y}" if           @grid[x + offset_x][y + offset_y] == nil
          @grid[x + offset_x][y + offset_y]
        end
      end
    end.inject(:+)
  end

  def outside_grid?(x, y)
    x < 0 || x >= @width || y < 0 || y >= @height
  end

  def generation
    @grid = @grid.map.with_index do |row, x|
      row.map.with_index do |point, y|
        case sibling_sum(x,y)
        when 0..1
          0
        when 2
          point
        when 3
          1
        when 4..8
          0
        else
          raise sibling_sum(x,y)
        end
      end
    end
  end

end

g = Grid.new
loop do
  puts g
  puts "\x1b[#{30}A"
  g.generation
  sleep 0.1
end

Dork :-)