And you are only proposing to add Any as a possible result for foreign
#10460: Allow foreign prim to return Any -------------------------------------+------------------------------------- Reporter: ezyang | Owner: ezyang Type: feature request | Status: new Priority: normal | Milestone: 7.12.1 Component: Compiler (Type | Version: 7.11 checker) | Keywords: Resolution: | Architecture: Operating System: Unknown/Multiple | Unknown/Multiple Type of failure: GHC rejects | Test Case: valid program | Blocking: Blocked By: | Differential Revisions: Related Tickets: | -------------------------------------+------------------------------------- Comment (by ezyang): prim not for other foreign declarations, correct? Yep.
Who converts the argument to Any? The caller? With unsafeCoerce?
Yes and yes. Another possibility is to accept arbitrary types for foreign prim ops (in the same way that GHC's primop mechanism works), but that's more work. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10460#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler