#5296: Add explicit type applications -------------------------------------+------------------------------------- Reporter: dsf | Owner: goldfire Type: feature request | Status: closed Priority: low | Milestone: 8.0.1 Component: Compiler (Type | Version: 7.0.3 checker) | Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: GHC rejects | Test Case: valid program | typecheck/should_compile/Vta{1,2} | typecheck/should_fail/VtaFail Blocked By: 1897 | Blocking: 10770 Related Tickets: #4466 | Differential Rev(s): Phab:D1681 Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): It depends on what ambiguity means. In a language with visible type application, {{{ foo :: (Show a, Read a) => String -> String }}} can be called quite easily. Thus the ambiguity check seems unhelpful here. Thus the decision to have `TypeApplications` turn on `AllowAmbiguousTypes`. I do see what you're getting at. Perhaps this is the wrong design, and I'm happy to think about changing it (although it does seem a bit late). I will say that if you do want the ambiguity check, you can always use `NoAllowAmbiguousTypes`. If you wish to pursue the issue, I think a good next step is posting to ghc-devs to see what others think. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/5296#comment:30 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler