Refactor ConDecl: Trac #14529

This patch refactors HsDecls.ConDecl.  Specifically

* ConDeclGADT was horrible, with all the information hidden
  inside con_res_ty.  Now it's kept separate, as it should be.

* ConDeclH98: use [LHsTyVarBndr] instead of LHsQTyVars for the
  existentials. There is no implicit binding here.

* Add a field con_forall to both ConDeclGADT and ConDeclH98
  which says if there is an explicit user-written forall.

* Field renamings in ConDecl
     con_cxt     to con_mb_cxt
     con_details to con_args

There is an accompanying submodule update to Haddock.

Also the following change turned out to remove a lot of clutter:

* add a smart constructor for HsAppsTy, namely mkHsAppsTy,
  and use it consistently. This avoids a lot of painful pattern
  matching for the common singleton case.

Two api-annotation tests (T10278, and T10399) are broken, hence marking
them as expect_broken(14529).  Alan is going to fix them, probably by
changing the con_forall field to
   con_forall :: Maybe SrcSpan
instead of Bool

1 files changed, 6 insertions, 1 deletions

diff --git a/compiler/utils/ListSetOps.hs b/compiler/utils/ListSetOps.hs
index c311ac9c85..a0fd9879bc 100644
--- a/compiler/utils/ListSetOps.hs
+++ b/compiler/utils/ListSetOps.hs
@@ -8,7 +8,7 @@
 {-# LANGUAGE CPP #-}
 
 module ListSetOps (
-        unionLists, minusList,
+        unionLists, minusList, deleteBys,
 
         -- Association lists
         Assoc, assoc, assocMaybe, assocUsing, assocDefault, assocDefaultUsing,
@@ -37,6 +37,11 @@ getNth :: Outputable a => [a] -> Int -> a
 getNth xs n = ASSERT2( xs `lengthExceeds` n, ppr n $$ ppr xs )
              xs !! n
 
+deleteBys :: (a -> a -> Bool) -> [a] -> [a] -> [a]
+-- (deleteBys eq xs ys) returns xs-ys, using the given equality function
+-- Just like 'Data.List.delete' but with an equality function
+deleteBys eq xs ys = foldl (flip (deleteBy eq)) xs ys
+
 {-
 ************************************************************************
 *                                                                      *