Keyword for exclusive or in ruby?

Question

Does Ruby have a plain-English keyword for exclusive or, like they have \"and\" and \"or\"? If not, is this because exclusive or doesn\'t allow evaluation short-cutting?

Answer 1

Any implementation of xor won't allow short circuiting. Both expressions need to be evaluated no matter what.

Ruby does provide the ^ operator, but this will choke on truthy values. I've implemented a function to handle the cases where I want an xor that behaves more like and and or:

def xor(a,b)
  (a and (not b)) or ((not a) and b)
end

Unlike ^, this function can be used in situations similar to the following:

xor("hello".match(/llo/), false) # => true
xor(nil, 1239)                   # => true
xor("cupcake", false)            # => false