This paper describes two Haskell libraries for property-based testing. Following the lead of QuickCheck (Claessen and Hughes 2000), these testing libraries SmallCheck and Lazy SmallCheck also use type-based generators to obtain test-sets of finite values for which properties are checked, and report any counter-examples found. But instead of using a sample of randomly generated values they test properties for all values up to some limiting depth, progressively increasing this limit. The paper explains the design and implementation of both libraries and evaluates them in comparison with each other and with QuickCheck. Categories and Subject Descriptors D.1.1 [Applicative (Functional)

Datatype-generic programming is defining functions that depend on the structure, or “shape”, of datatypes. It has been around for more than 10 years, and a lot of progress has been made, in particular in the lazy functional programming language Haskell. There are more than 10 proposals for generic programming libraries or language extensions for Haskell. To compare and characterize the many generic programming libraries in a typed functional language, we introduce a set of criteria and develop a generic programming benchmark: a set of characteristic examples testing various facets of datatype-generic programming. We have implemented the benchmark for nine existing Haskell generic programming libraries and present the evaluation of the libraries. The comparison is useful for reaching a common standard for generic programming, but also for a programmer who has to choose a particular approach for datatype-generic programming.

We develop a Haskell library for functional-logic programming, motivated by the implementation of Wired, a relational embedded domain-specific language for describing and analysing digital circuits at the VLSI-layout level. Compared to a previous library for logic programming by Claessen and Ljunglöf, we support residuation, easier creation of logical data types, and pattern matching. We discuss other applications of our library, including test-data generation, and various extensions, including lazy narrowing.

Datatype-generic programming is about defining functions that depend on the structure, or “shape”, of datatypes. It has been around for more than 10 years, and a lot of progress has been made, in particular in the lazy functional programming language Haskell. There are more than 10 proposals for generic programming libraries or language extensions for Haskell. In this paper we compare and characterise the many generic programming libraries for Haskell. To that end, we introduce a set of criteria and develop a generic programming benchmark: a set of characteristic examples testing various facets of datatype-generic programming. We have implemented the benchmark for ten existing Haskell generic programming libraries and present the evaluation of the libraries. The comparison is useful for reaching a common standard for generic programming, but also for a programmer who has to choose a particular approach for datatype-generic programming.