#11515: PartialTypeSignatures suggests a redundant constraint with constraint families -------------------------------------+------------------------------------- Reporter: goldfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 Resolution: | Keywords: TypedHoles 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 RyanGlScott): This appears to be fixed, as of GHC 8.2.2: {{{ $ /opt/ghc/8.2.2/bin/ghci Bug.hs GHCi, version 8.2.2: http://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/rgscott/.ghci [1 of 1] Compiling Bug ( Bug.hs, interpreted ) Bug.hs:7:20: error: • Found type wildcard ‘_’ standing for ‘()’ To use the inferred type, enable PartialTypeSignatures • In the type signature: foo :: (ShowSyn a, _) => a -> String | 7 | foo :: (ShowSyn a, _) => a -> String | ^ }}} I'll add a regression test. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11515#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler