Kurt Stephens

  $ irb 
  irb(main):001:0> require “ks_rational.rb”
  => true
  irb(main):002:0> r = Rational.new! 0, 0
  => Rational0, 0
  irb(main):003:0> r.zero?
  => true
  irb(main):004:0> r = Rational(0, 0)
  ZeroDivisionError: denominator is zero
      from ks_rational.rb:76:in `reduce’
      from ks_rational.rb:39:in `Rational’
      from (irb):2

I’d suggest a warning in the RDoc for #zero? similar to the one for #==. Rational.new! is voodoo! I’d almost recommend it should be Rational.faux!