Documentation

Known tactic for deriving arbitrary :: Gen a. This tactic splits the type's data cons into terminal and inductive cases, and generates code that produces a terminal if the QuickCheck size parameter is <=1, or any data con otherwise. It correctly scales recursive parameters, ensuring termination.

Helper data type for the generator of a specific data con.

Make a Generator for a given tycon instantiated with the given [Type].

Check if the given TyCon exists anywhere in the Type.

Generate the correct sort of call to arbitrary. For recursive calls, we need to scale down the size parameter, either by a constant factor of 1 if it's the only recursive parameter, or by div n where n is the number of recursive parameters. For all other types, just call arbitrary directly.