#8634: Relax functional dependency coherence check ("liberal coverage condition") -------------------------------------+------------------------------------- Reporter: danilo2 | Owner: Type: feature request | Status: new Priority: high | Milestone: 7.12.1 Component: Compiler | Version: 7.7 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Blocked By: | Test Case: Related Tickets: #1241, #2247, | Blocking: #8356, #9103, #9227 | Differential Revisions: Phab:D69 -------------------------------------+------------------------------------- Comment (by simonpj):
Is there a wiki page or similar describing the meaning of functional dependencies under `DysfunctionalDependencies`?
See the end of comment:14. This stuff needs to end up in the user manual though. It's a simple, easily-specified change. I don't think we should hold it up because of a vague aspiration to implement fundeps in terms of type families; I'm sure there will be lots of ''other'' wrinkles to that. I would much prefer it done as a '''per-instance''' pragma, since we now have the technology to do that, rather than as a module-wide pragma. All it needs is for someone to do it. I'm happy to advise. Simon -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8634#comment:64 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler