This is a list of Frequently Asked Questions about OneTuple, the optional Haskell singleton tuple type. Some of these are, of course, merely anticipated FAQs. Q 1. What's the point, if you can't support the same syntax as 'normal' tuples? A 1. You can hack it up in TH if you want -- patches are welcome! Simplicity and (near) H98 compatibility were goals in building OneTuple. Q 2. Why define 'data OneTuple' instead of just a type alias? A 2. For laziness and pattern matching similar to other tuples. Q 3. Isn't this the same as ? A 3. Could be, but this one's sold as a tuple! Q 4. Singleton tuples don't make sense! They're isomorphic to their component type! A 4. Yes, that's true, up to laziness.