#15677: Valid hole fits and GADT type variable names -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.8.1 Component: Compiler | Version: 8.6.1 Resolution: | Keywords: TypedHoles, | GADTs Operating System: Unknown/Multiple | Architecture: Type of failure: Poor/confusing | Unknown/Multiple error message | Test Case: Blocked By: | Blocking: Related Tickets: #9091 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Tritlo): Well, at least the situation for #9091 is a bit better now, with constraints shown by default: {{{ tritlo@nietzsche:~/Code$ ghc t9091.hs -XGADTs [1 of 1] Compiling T9091 ( t9091.hs, t9091.o ) t9091.hs:7:9: error: • Found hole: _ :: Int • In the expression: _ In an equation for ‘h’: h Y x = _ • Relevant bindings include x :: a (bound at t9091.hs:7:5) h :: X a -> a -> a (bound at t9091.hs:7:1) Constraints include a ~ Int (from t9091.hs:7:3) Valid hole fits include x :: a (bound at t9091.hs:7:5) maxBound :: forall a. Bounded a => a with maxBound @Int (imported from ‘Prelude’ at t9091.hs:1:8-12 (and originally defined in ‘GHC.Enum’)) minBound :: forall a. Bounded a => a with minBound @Int (imported from ‘Prelude’ at t9091.hs:1:8-12 (and originally defined in ‘GHC.Enum’)) | 7 | h Y x = _ }}} but this is still an issue. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15677#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler