#11224: Program doesn't preserve semantics after pattern synonym inlining. -------------------------------------+------------------------------------- Reporter: anton.dubovik | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 7.10.2 Resolution: | Keywords: Operating System: Windows | Architecture: x86_64 Type of failure: Incorrect result | (amd64) at runtime | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by mpickering): I think the problem is in this part of `tcTySig` {{{ ; let (_, pat_ty) = tcSplitFunTys ty' univ_set = tyCoVarsOfType pat_ty (univ_tvs, ex_tvs) = partition (`elemVarSet` univ_set) qtvs' }}} Maybe the correct solution is to avoid splitting tyvars into ex/univ at this stage as it's impossible to tell which they are without looking at the pattern. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11224#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler