#11456: Type application and :set +c command cause panic -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 Resolution: | Keywords: | TypeApplications GHCi 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 rwbarton): It does actually, assuming you mean replacing `show` by `id` in the ticket. `GHCi.UI.Info.processAllTypeCheckedModule` is trying to desugar all the spans in the typechecked program individually to find out their types. One of those spans is `@Int`, which can't be desugared outside of the context `show @Int`. We should skip such subexpressions: any `HsTypeOut` constructor. Since this code is written in Generics-ese, I don't feel like trying to fix it myself. (Also, surely there is a more sensible way to collect this data then desugaring every span to find out its type, when we have already type checked the whole module?) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11456#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler