Introduce YES and NO as aliases of true and false
I have a patch introducing the constants YES/NO as aliases of true/false. You can check it out here: https://github.com/gsamokovarov/ruby/compare/trunk...yes-no
While I don't expect this to be accepted, I think it can start a discussion around supporting it.
There is a movement in recent languages to let YES/NO express TRUE/FALSE. Objective C, CoffeeScript and markup languages like YAML are some examples of that. I thing it works really well for ruby scripts, used as configuration files. The rails config/* files seem like great candidates for YES/NO usage.
Implementation wise, I choose to go with TRUE/FALSE like constants, rather than extra yes/no keywords as it seemed to me like the most unobtrusive way to introduce those.
Please, excuse me if this has been discussed before.