Re: [GHC] #13347: Abstract classes in hs-boot should not be treated as injective

#13347: Abstract classes in hs-boot should not be treated as injective -------------------------------------+------------------------------------- Reporter: ezyang | Owner: (none) Type: bug | Status: patch Priority: low | Milestone: Component: Compiler (Type | Version: 8.1 checker) | Resolution: | Keywords: hs-boot Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D3236 Wiki Page: | -------------------------------------+------------------------------------- Comment (by Edward Z. Yang ): In [changeset:"fb5cd9d6d6185afe6d4ef2f3df3f895b6d0abf4c/ghc" fb5cd9d/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="fb5cd9d6d6185afe6d4ef2f3df3f895b6d0abf4c" Properly represent abstract classes in Class and IfaceDecl Summary: Previously, abstract classes looked very much like normal classes, except that they happened to have no methods, superclasses or ATs, and they came from boot files. This patch gives abstract classes a proper representation in Class and IfaceDecl, by moving the things which are never defined for abstract classes into ClassBody/IfaceClassBody. Because Class is abstract, this change had ~no disruption to any of the code in GHC; if you ask about the methods of an abstract class, we'll just give you an empty list. This also fixes a bug where abstract type classes were incorrectly treated as representationally injective (they're not!) Fixes #13347, and a TODO in the code. Signed-off-by: Edward Z. Yang Test Plan: validate Reviewers: simonpj, bgamari, austin Subscribers: goldfire, thomie Differential Revision: https://phabricator.haskell.org/D3236 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13347#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler