my $life = new life: 20;

##</code><code>##


loop { $life.display() }

##</code><code>##


class life
{
  has Int          $.count;
  has Int          $.max;
  has Array of Bit @.grid;

##</code><code>##


  method BUILD(Int $dim)

##</code><code>##

  {
    $.count = 0;
    $.max = $dimension-1;
    my Array of Bit @grid is dim($dim,$dim) is default(0);

##</code><code>##

    @grid[$dim / 2 - 1][$dim / 2    ] = 1;
    @grid[$dim / 2 - 1][$dim / 2 + 1] = 1;
    @grid[$dim / 2    ][$dim / 2    ] = 1;
    @grid[$dim / 2    ][$dim / 2 - 1] = 1;
    @grid[$dim / 2 + 1][$dim / 2    ] = 1;
    @.grid := @grid;

##</code><code>##

  }

  sub iterate (&block) 

##</code><code>##

  {
    for 0..$.max -> $x 

##</code><code>##

   {
      for 0..$.max -> $y 
      {
        block($x,$y);
      }
    }
  }

  method calculate() is private 
  {
    my @newgrid;
    iterate
    { 
      my $live = sum(@.grid[$^x-1..$^x+1][$^y-1..$^y+1]);
      @newgrid[$^x][$^y] =  $live==2 && @.grid[$^x][$^y] 
                         || $live==3;
    }

##</code><code>##

    @.grid = @newgrid;
  }

  method display
  {
    iterate { 
      print $.grid[$^x][$^y] ?? '+' :: '.';
      print "\n" if $^x == $.max;
    }
    print "\n";
    print "Turn $(++$.count), press enter to continue or ctl-c to quit;
    <$*IN>;

##</code><code>##

    .calculate();
  }
}