#9242: Implement {-# OVERLAPPABLE #-} and {-# INCOHERENT #-} pragmas -------------------------------------+------------------------------------- Reporter: simonpj | Owner: diatchki Type: feature | Status: new request | Milestone: Priority: normal | Version: 7.8.2 Component: Compiler | Keywords: Resolution: | Operating System: Unknown/Multiple Differential Revisions: | Type of failure: None/Unknown Architecture: | Test Case: Unknown/Multiple | Blocking: Difficulty: Unknown | Blocked By: | Related Tickets: | -------------------------------------+------------------------------------- Comment (by diatchki): I thought some more about the OVERLAPPING and OVERLAPPABLE idea, but I couldn't come up with examples where I'd want to use that feature. So, for the time being, I'll leave the implementation as is, and document it accordingly. Related to this: having looked at the code for the instance database, I think it would be quite easy to implement "instance chains", which eliminates the need for overlapping instances in pretty much all situations that I've encountered them. I outlined the details in ticket #9334. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9242#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler