extra_predicates.rb

class Object
  # just a more verbose way of reversing predicates.
  #
  # lets you do things like 
  # '    '.not_blank? # => false
  # instead of
  # !'   '.blank?     # => false
  # doesn't work sometimes if someone is using method_missing
  # somewhere (i.e. rails)
  def method_missing(method, *args, &block)
    if matched= method.to_s.match(/(not_)(\w*\?$)/)
      super unless self.respond_to? matched[2].to_sym
      !self.send "#{matched[2]}"
    else
      super
    end
  end
  
  # grammar for the masses.
  # from utility belt, or something. maybe.
  def is_an? klass
    is_a? klass
  end
end