Re: [GHC] #10361: DeriveAnyClass does not fill in associated type defaults

#10361: DeriveAnyClass does not fill in associated type defaults -------------------------------------+------------------------------------- Reporter: kosmikus | Owner: dreixel Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 7.10.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D1283 -------------------------------------+------------------------------------- Comment (by Ben Gamari ): In [changeset:"2f74be9c8af1e167b21df1a27b96b6626cd446a9/ghc" 2f74be9c/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="2f74be9c8af1e167b21df1a27b96b6626cd446a9" Fill in associated type defaults with DeriveAnyClass Summary: Unlike `-XDefaultSignatures`, `-XDeriveAnyClass` would not fill in associated type family defaults when deriving a class which contained them. In order to fix this properly, `tcATDefault` needed to be used from `TcGenDeriv`. To avoid a module import cycle, `tcATDefault` was moved from `TcInstDcls` to `TcClsDcl`. Fixes #10361. Test Plan: ./validate Reviewers: kosmikus, dreixel, bgamari, austin, simonpj Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D1283 GHC Trac Issues: #10361 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10361#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler