#11427: TypeSynonyms not deduced -------------------------------------+------------------------------------- Reporter: phadej | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1-rc1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- {{{ class (AllF f xs, SListI xs) => All (f :: k -> Constraint) (xs :: [k]) instance #if __GLASGOW_HASKELL__ >= 710 {-# OVERLAPPING #-} #endif All SListI xss => SingI (xss :: [[k]]) where sing = sList }}} fails with {{{ • Could not deduce (SListI xss) arising from the superclasses of an instance declaration from the context: All SListI xss bound by the instance declaration at src/Generics/SOP/Constraint.hs:141:3-40 • In the instance declaration for ‘SingI xss’ }}} See https://travis-ci.org/well-typed/generics-sop/jobs/102388817 and https://github.com/phadej/generics-sop/tree/ghc-8.0.1 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11427 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler