#7624: Handling ImplicitParams in Instance Declaration
------------------------------+---------------------------------------------
Reporter: philipjf | Owner:
Type: bug | Status: new
Priority: normal | Component: Documentation
Version: 7.6.1 | Keywords: ImplicitParams
Os: Unknown/Multiple | Architecture: Unknown/Multiple
Failure: Documentation bug | Blockedby:
Blocking: | Related:
------------------------------+---------------------------------------------
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.
[http://joyoftypes.blogspot.com/2013/01/using-compiler-bugs-for-fun-and-
profit.html Why I think the (undocumented) current behavior is correct]
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7624>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
_______________________________________________
ghc-tickets mailing list
[email protected]
http://www.haskell.org/mailman/listinfo/ghc-tickets
