function combat(world, index)
  world.hp[index] = world.hp[index] - world.damage[index]
end

function cull_dead(world, index)
  if world.hp[index] < 0 then
    world.dead[index] = true
  end
end


function handler(world)
  print("world count", world.count)

  for i = 1, world.count + 1, 1
  do
    combat(world, i)
    cull_dead(world, i)

    print(world.name[i],
        "HP now", world.hp[i],
        "damage", world.damage[i],
        "dead", world.dead[i])
  end
end