Conway Ruby

gistfile1.rb

def parse(filename)
  contents = File.read(filename)
  [contents.gsub("\n", "").split(//), contents.split[0].size]
end

def neighbours(i, s)
  f,l=[i%s==0,i%s==s-1]
  [(f ? -1 : i-s-1),i-s,(l ? -1 : i-s+1),(f ? -1 : i-1),(l ? -1 : i+1),(f ? -1 : i+s-1),i+s,(l ? -1 : i+s+1) ].reject { |i| i < 0 }
end

g,s=parse(ARGV[0])
while true do
  system "clear"
  g=g.each_with_object([]).with_index do |(c, ng), i|
    a=neighbours(i,s).map { |i| g[i] }.count("X")
    ng[i]=c=="X" ? (a<2 || a>3) ? "O" : "X" : (a==3) ? "X" : "O"
  end
  g.each_slice(s) { |r| puts r.join }
  sleep 1
end