The "Hacking Agenda" #428

Involving @koengit @nick8325 @UlfNorell and @Rewbert:

Instances

• Arbitrary instances for everything in base (and other qc dependencies)
• Super clever TH magic to find all the types and generate properties
  • Enumerate all modules in base and get all the data types
  • Minimal: type check arbitrary @TheType
  • Better: Monomorphise and generate a properties to test the arbitrary instance
  • Manually exclude modules/types (to avoid writing clever rules for which
    types to support)
• See CollectDataTypes.hs and RunCollectDataTypes.hs.

Parallel fork

• Robert gives a nice presentation of what's going on

• We should decide on some design principles:

  • we care only about locally minimal counterexamples
  • we want the features module
  • we don't care about parallel quickcheck exploring sizes
    deterministically
  • we do care about sizes being explored in order small to big

API for test runners

• Tasty and HSpec install their own callbacks
  • Can we make PRs for them using Robert's new API?
  • Robert has the code, but needs some version juggling to work with different
    versions of QuickCheck.

Cleanup

• Drop ghc 7 support
• Clean up flag mess in cabal file
• Add MicroHs support
  • Lennart: "needs random numbers, this is hard!"