#11405: Incorrect failure of type-level skolem escape check -------------------------------------+------------------------------------- Reporter: goldfire | Owner: goldfire Type: bug | Status: new Priority: highest | Milestone: 8.0.1 Component: Compiler | Version: 8.0.1-rc1 Resolution: | Keywords: TypeInType 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 gridaphobe): Is it just a problem because of `x0`, ie would {{{ x = \ @(v :: Levity) @(a :: TYPE v) ($dict :: (?callStack :: CallStack)) -> let $dict' = ... in undefined @v @a $dict' }}} be OK? If so, can we change the desugarer to not generate the intermediate binder when there's only one use and no recursion? I'm not sure that would be a general fix, but it would fix the immediate problem. (Also, why are levity-polymorphic binders not allowed? Is this explained somewhere? Just curious.) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11405#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler