haskell@gentoo.org Gentoo Haskell Feat (Functional Enumeration of Abstract Types) provides enumerations as functions from natural numbers to values (similar to @toEnum@ but for any algebraic data type). This can be used for SmallCheck-style systematic testing, QuickCheck style random testing, and hybrids of the two. The enumerators are defined in a very boilerplate manner and there is a Template Haskell script for deriving the class instance for most types. "Test.Feat" contain a subset of the other modules that should be sufficient for most test usage. There are some small and large example in the tar ball.