1. 23 Jul, 2011 1 commit
    • Simon Peyton Jones's avatar
      Reject bad 'deriving' directives (fixes Trac #5287) · 49861e71
      Simon Peyton Jones authored
      The 'deriving' mechanism that infers the context for
      an instance declarations was going into a loop, as a
      result of an instance like
             instance C a b => D [a]
      where the 'b' isn't mentioned in the head.
      
      This patch identifies those cases.  I also needed to make
      TcErrors generate a suitable error message.  On the way
      I improved the reporting of "ambiguous" variables;
      for example arrowfail001 now generates a better message.
      49861e71
  2. 22 Jul, 2011 9 commits
  3. 21 Jul, 2011 11 commits
  4. 20 Jul, 2011 19 commits