• Edward Z. Yang's avatar
    Properly represent abstract classes in Class and IfaceDecl · fb5cd9d6
    Edward Z. Yang authored
    
    
    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: default avatarEdward Z. Yang <ezyang@cs.stanford.edu>
    
    Test Plan: validate
    
    Reviewers: simonpj, bgamari, austin
    
    Subscribers: goldfire, thomie
    
    Differential Revision: https://phabricator.haskell.org/D3236
    fb5cd9d6
TcRnDriver.hs 110 KB