Haskell Program Coverage

The authors describe the design, implementation and use of HPC, a toolkit to record and display Haskell Program Coverage. HPC includes tools that instrument Haskell programs to record program coverage, run instrumented programs, and display information derived from coverage data in various ways. Computer programs need thorough testing. To be thorough may mean many things, but surely this is one of them: testing should cover every reachable part of the program. To meet this coverage requirement, they must first establish exactly what should be regarded as program parts. Then as they test their programs they need convenient ways to record and review which parts have been covered and which have not.