#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: | Architecture: Unknown/Multiple Operating System: | Difficulty: Unknown Unknown/Multiple | Blocked By: Type of failure: | Related Tickets: None/Unknown | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by simonpj): David, I don't think it's feasible to remove `OVERLAPS` at the moment, unless you can amass some real support for it. * Main reason: people have argued precisely the opposite: that `OVERLAPPING` and `OVERLAPPABLE` are too complicated, and they should be removed in favour of just `OVERLAPS`. In principle I like the idea of forcing people to be explicit, but I think it's bridge too far. * Tiresome reason: the parser isn't up to parsing two pragmas; currently `{-# OVERLAPPING, OVERLAPPABLE #-}` isn't allowed. Someone would have to fix that. Of course, if `-XSafe` is on, you can modify the behaviour if you like. So if you want to propose something along those lines, go ahead. Simon -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9242#comment:32 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler