$: << '..'
require 'sloop'

EllipseTraits = sloop {
  # Archimedes
  def_area { Math::PI * a * b }

  # Ramanujan
  def_circumfence { Math::PI * (3*(a+b) - Math.sqrt((3*a+b)*(a+3*b))) }

  def_inspect { "#(an ellipse with radii #{a} and #{b})" }
}

CircleTraits = sloop {
  # Archimedes
  def_circumfence { Math::PI * 2 * r }

  def_inspect { "#(a circle radius #{r})" }
}

Ellipse = sloop {
  inherit EllipseTraits
  
  self.a = 0
  self.b = 0
}

Circle = sloop {
  inherit Ellipse
  inherit CircleTraits
  
  self.r = 0
  def_a { r }
  def_b { r }
}


if $0 == __FILE__

  e = Ellipse.clone
  e.a = 1
  e.b = 5

  p [e, e.circumfence, e.area]

  c = Circle.clone
  c.r = 4

  p [c, c.circumfence, c.area]
  
end