#15743: Nail down the Required/Inferred/Specified story -------------------------------------+------------------------------------- Reporter: simonpj | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.6.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire):
is it even possible to specify the position of an inferred variable other than at the front?
It isn't possible to specify the position of an inferred variable. Full stop. (At least, not until we have explicit specificity.) But this isn't just about Inferred variables. It's also about Specified ones. Here's a slight tweak to `T`: {{{#!hs data T k (c :: k) (a :: Proxy c) (b :: Proxy d) (x :: SimilarKind a b) }}} I've given `b` a kind that mentions `d`. This makes `d` Specified. But poor `d` still must come ''after'' `k`. We can still go ahead with option (1) (which is what I've been reluctantly leaning toward as well), but I'm clarifying here that the problem isn't just with Inferred. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15743#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler