And here we finally come to GADTs! It's just a way to define data types using pattern matching and constants on the left side of "data" statements!

When pattern matching, these constraints are made available to discharge constraints in the body of the match.

The Language.Haskell.TH.Syntax.Quasi class now has a qAddDependentFile method, which splices can use to indicate that the result of the splice depends upon the contents of a file. This tells the compiler that if the file has changed then it will need to recompile the module containing the splice.