Programming Languages and Systems

Volume 6012 of the series Lecture Notes in Computer Science pp 125-144

Testing Polymorphic Properties

  • Jean-Philippe BernardyAffiliated withChalmers University of Technology
  • , Patrik JanssonAffiliated withChalmers University of Technology
  • , Koen ClaessenAffiliated withChalmers University of Technology


This paper is concerned with testing properties of polymorphic functions. The problem is that testing can only be performed on specific monomorphic instances, whereas parametrically polymorphic functions are expected to work for any type. We present a schema for constructing a monomorphic instance for a polymorphic property, such that correctness of that single instance implies correctness for all other instances. We also give a formal definition of the class of polymorphic properties the schema can be used for. Compared to the standard method of testing such properties, our schema leads to a significant reduction of necessary test cases.


polymorphism parametricity initiality testing