#9558: "Illegal equational constraint" that might not be the users fault -------------------------------------+------------------------------------- Reporter: rrnewton | Owner: Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 7.9 Resolution: invalid | Keywords: Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Difficulty: Unknown Type of failure: | Blocked By: None/Unknown | Related Tickets: Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Changes (by simonpj): * status: new => closed * resolution: => invalid Comment: Reid is right. Is the change a good design choice? In general I think "yes". The language extensions are meant to say whether or not you are using a language extension in a module; and if you need an extension to write down the type of a function you are defining I think that yes, you are using the extension. But if it causes major backward-compatibility pain, that might have outweighed it (if we'd known). But now 7.8 is out. I'll close this as invalid (since it is by-design), but if anyone feels strongly we should actually change back (in 7.10) to the previous design (where GHC would infer a type that you could not write in a type signature without adding more flags), then please open a new ticket to say so and why. Simon -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9558#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler