How do I enable language extensions from within GHCi?

问题

I'm trying to enable XRankNTypes in GHCi. How do I do this?

回答1:

:set -XRankNTypes. The -X part is a compiler switch, by the way, extension is called just RankNTypes.

来源：https://stackoverflow.com/questions/12584884/how-do-i-enable-language-extensions-from-within-ghci