Handling ImplicitParams in Instance Declaration
|Reported by:||philipjf||Owned by:|
|Type of failure:||Documentation bug||Test Case:|
|Related Tickets:||Differential Revisions:|
Description (last modified by simonpj)
The GHC documentation states that ImplicitParam's may not be used in class or instance declaration constraints. see for example http://www.haskell.org/ghc/docs/7.6.1/html/users_guide/other-type-extensions.html In practice though, at least on the Mac, all recent version of GHC have permitted such instances. At the very least the documentation should make clear that the compiler might permit such instances, but they have undefined behaviour. Ideally, these would simply be permitted.