Automatically generate comparitive definitions based on attribute fields.

  include Comparable[:a, :b]

is equivalent to including a module containing:

  def <=>(other)
    cmp = self.a <=> other.a; return cmp unless cmp == 0
    cmp = self.b <=> other.b; return cmp unless cmp == 0
    0
  end

Returns the lower of self or x.

  4.at_least(5)  #=> 5
  6.at_least(5)  #=> 6

CREDIT: Florian Gross

Returns the greater of self or x.

  4.at_most(5)  #=> 4
  6.at_most(5)  #=> 5

CREDIT: Florian Gross

Alias for clip

Alias for at_most

Returns self if above the given lower bound, or within the given lower and upper bounds, otherwise returns the the bound of which the value falls outside.

  4.clip(3)    #=> 4
  4.clip(5)    #=> 5
  4.clip(2,7)  #=> 4
  9.clip(2,7)  #=> 7
  1.clip(2,7)  #=> 2

CREDIT Florian Gross, Trans

Alternate name for comparison operator #<=>.

  3.cmp(1)   #=>  1
  3.cmp(3)   #=>  0
  3.cmp(10)  #=> -1

This fundamental compare method is used to keep comparison compatible with succ.

CREDIT: Peter Vanbroekhoven