I’m writing a validation that tests the presence of two optional keys
rule :foo, :bar do
unless values.key?(:foo) ^ values.key?(:bar)
key.failure("must have one of: foo, bar")
end
end
(Seldom do I get to write an XOR!)
It was surprising to me that I couldn’t write key?(:bar) instead, since Evaluator#key? merely forwards to Values#key?. Doesn’t seem like this omission was intentional.
I have a working patch that implements this. Are you interested in a PR?
