L.S., I just read the article "Apple Patents Swift".[0] It says that Apple has two patents regarding Swift: [1][2]; these patents state, amongst others, that there are new types of variables: "Additionally, an embodiment of the new language introduces advanced types not found in Objective-C. These types include Tuples and Optionals. Tuples enable a developer to create and pass groupings of values. Tuples group multiple values into a single compound value." and "In one embodiment, an optional type is provided that handles the absence of a value. Optionals are a way to say either “there is a value, and it equals x” or “there isn't a value at all.”" I hope we don't get arrested for using the Maybe monad or tuples in Haskell. Regards, Henk-Jan van Tuyl [0] https://www.i-programmer.info/news/98-languages/12495-apple-patents-swift.ht... [1] https://patents.google.com/patent/US9952841B2 [2] https://patents.google.com/patent/US9329844B2 -- Message from Stanford University: Folding@home What if you could share your unused computer power to help find a cure? In just 5 minutes you can join the world's biggest networked computer and get us closer sooner. Watch the video. http://foldingathome.stanford.edu/ -- http://members.chello.nl/hjgtuyl/tourdemonad.html Haskell programming --