test.nim

type
  Sprite {.pure inheritable.} = object
    x, y: float
    image: string
  
  Fighter = object of Sprite
    health: float
    strength: float

proc move(s:var Sprite, x, y:float) =
  s.x += x
  s.y += y

proc touch(f:var Fighter, other:Fighter) =
  f.health -= other.strength
  if f.health < 0:
    echo "Ship ", f.image, " dead!"

proc print(f:Fighter) =
  echo f.x, ", ", f.y, ", ", f.image, ", ", f.health, ", ", f.strength

proc newFighter(x, y:float, image:string, health, strength:float): Fighter =
  when Fighter is ref:
    result.new()
  result.x = x
  result.y = y
  result.image = image
  result.health = health
  result.strength = strength

var
  tie = newFighter(1, 2, "Tie Fighter", 1, 0.1)
  xwing = newFighter(3, 4, "Rebel XWing", 1, 0.5)

echo sizeof Sprite
echo sizeof Fighter
tie.print()
xwing.print()
tie.move(10, 20)
xwing.move(5, 3)
tie.touch(xwing)
xwing.touch(tie)
tie.print()
xwing.print()