• Ryan Scott's avatar
    Fix Template Haskell's handling of infix GADT constructors · 01634277
    Ryan Scott authored
    This is the second (and hopefully last) fix needed to make TH handle
    GADTs properly (after D1465). This Diff addresses some issues with infix
    GADT constructors, specifically:
    
    * Before, you could not determine if a GADT constructor was declared
      infix because TH did not give you the ability to determine if there is
      a //user-specified// fixity declaration for that constructor. The
      return type of `reifyFixity` was changed to `Maybe Fixity` so that it
      yields `Just` the fixity is there is a fixity declaration, and
      `Nothing` otherwise (indicating it has `defaultFixity`).
    * `DsMeta`/`Convert` were changed so that infix GADT constructors are
      turned into `GadtC`, not `InfixC` (which should be reserved for
      Haskell98 datatype declarations).
    * Some minor fixes to the TH pretty-printer so that infix GADT
      constructors will be parenthesized in GADT signatures.
    
    Fixes #11345.
    
    Test Plan: ./validate
    
    Reviewers: goldfire, austin, bgamari, jstolarek
    
    Reviewed By: jstolarek
    
    Subscribers: thomie
    
    Differential Revision: https://phabricator.haskell.org/D1744
    
    GHC Trac Issues: #11345
    01634277
all.T 15.8 KB