Ordenando Puntos

Véase el código en 14.1.6

• Comparable
• Enumerable

include Comparable   # Mix in methods from the Comparable module.

# Define an ordering for points based on their distance from the origin.
# This method is required by the Comparable module.
def <=>(other)
  return nil unless other.instance_of? Point
  @x**2 + @y**2 <=> other.x**2 + other.y**2
end

p,q = Point.new(1,0), Point.new(0,1)
p == q        # => false: p is not equal to q
p < q         # => false: p is not less than q
p > q         # => false: p is not greater than q