#11715: Constraint vs * -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: bug | Status: new Priority: high | Milestone: 8.2.1 Component: Compiler (Type | Version: 8.0.1-rc1 checker) | Resolution: | Keywords: Typeable Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): Hm. Perhaps you're right that my suggestion goes against the spirit of Haskell constraints and that it would be more sensible to simply rename `with` to `incoherentWith`. Instead of my proposed error, we could simply add a warning when GHC detects (on a best effort basis) an ambiguous constraint. This warning would be triggered in `cmp`, for example, and silly uses of `incoherentWith`. Or perhaps not in `cmp` because GHC can detect that the ambiguously satisfied constraint is actually a class constraint and therefore assumed to be coherent. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11715#comment:27 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler