Major patch to introduce TyConBinder

Before this patch, following the TypeInType innovations,
each TyCon had two lists:
  - tyConBinders :: [TyBinder]
  - tyConTyVars  :: [TyVar]

They were in 1-1 correspondence and contained
overlapping information.  More broadly, there were many
places where we had to pass around this pair of lists,
instead of a single list.

This commit tidies all that up, by having just one list of
binders in a TyCon:

  - tyConBinders :: [TyConBinder]

The new data types look like this:

  Var.hs:
     data TyVarBndr tyvar vis = TvBndr tyvar vis
     data VisibilityFlag = Visible | Specified | Invisible
     type TyVarBinder = TyVarBndr TyVar VisibilityFlag

  TyCon.hs:
     type TyConBinder = TyVarBndr TyVar TyConBndrVis

     data TyConBndrVis
       = NamedTCB VisibilityFlag
       | AnonTCB

  TyCoRep.hs:
     data TyBinder
       = Named TyVarBinder
       | Anon Type

Note that Var.TyVarBdr has moved from TyCoRep and has been
made polymorphic in the tyvar and visiblity fields:

     type TyVarBinder = TyVarBndr TyVar VisibilityFlag
        -- Used in ForAllTy
     type TyConBinder = TyVarBndr TyVar TyConBndrVis
        -- Used in TyCon

     type IfaceForAllBndr  = TyVarBndr IfaceTvBndr VisibilityFlag
     type IfaceTyConBinder = TyVarBndr IfaceTvBndr TyConBndrVis
         -- Ditto, in interface files

There are a zillion knock-on changes, but everything
arises from these types.  It was a bit fiddly to get the
module loops to work out right!

Some smaller points
~~~~~~~~~~~~~~~~~~~
* Nice new functions
    TysPrim.mkTemplateKiTyVars
    TysPrim.mkTemplateTyConBinders
  which help you make the tyvar binders for dependently-typed
  TyCons.  See comments with their definition.

* The change showed up a bug in TcGenGenerics.tc_mkRepTy, where the code
  was making an assumption about the order of the kind variables in the
  kind of GHC.Generics.(:.:).  I fixed this; see TcGenGenerics.mkComp.

3 files changed, 7 insertions, 10 deletions

diff --git a/compiler/vectorise/Vectorise/Generic/PData.hs b/compiler/vectorise/Vectorise/Generic/PData.hs
index 23cd0a2cb0..9fbe1283f2 100644
--- a/compiler/vectorise/Vectorise/Generic/PData.hs
+++ b/compiler/vectorise/Vectorise/Generic/PData.hs
@@ -51,9 +51,8 @@ buildDataFamInst name' fam_tc vect_tc rhs
             rep_ty   = mkTyConApp rep_tc tys'
             pat_tys  = [mkTyConApp vect_tc tys']
             rep_tc   = mkAlgTyCon name'
-                           (mkTyBindersPreferAnon tyvars' liftedTypeKind)
+                           (mkTyConBindersPreferAnon tyvars' liftedTypeKind)
                            liftedTypeKind
-                           tyvars'
                            (map (const Nominal) tyvars')
                            Nothing
                            []          -- no stupid theta
@@ -85,7 +84,7 @@ buildPDataDataCon orig_name vect_tc repr_tc repr
                             (map (const no_bang) comp_tys)
                             (Just $ map (const HsLazy) comp_tys)
                             []                     -- no field labels
-                            tvs (map (mkNamedBinder . mkTyVarBinder Specified) tvs)
+                            (mkTyVarBinders Specified tvs)
                             []                     -- no existentials
                             []                     -- no eq spec
                             []                     -- no context
@@ -129,7 +128,7 @@ buildPDatasDataCon orig_name vect_tc repr_tc repr
                             (map (const no_bang) comp_tys)
                             (Just $ map (const HsLazy) comp_tys)
                             []                     -- no field labels
-                            tvs (map (mkNamedBinder . mkTyVarBinder Specified) tvs)
+                            (mkTyVarBinders Specified tvs)
                             []                     -- no existentials
                             []                     -- no eq spec
                             []                     -- no context
diff --git a/compiler/vectorise/Vectorise/Type/Env.hs b/compiler/vectorise/Vectorise/Type/Env.hs
index 0bcdf0c4a8..b6c8bec3fc 100644
--- a/compiler/vectorise/Vectorise/Type/Env.hs
+++ b/compiler/vectorise/Vectorise/Type/Env.hs
@@ -360,7 +360,7 @@ vectTypeEnv tycons vectTypeDecls vectClassDecls
         origName  = tyConName origTyCon
         vectName  = tyConName vectTyCon
 
-        mkSyn canonName ty = mkSynonymTyCon canonName [] (typeKind ty) [] [] ty
+        mkSyn canonName ty = mkSynonymTyCon canonName [] (typeKind ty) [] ty
 
         defDataCons
           | isAbstract = return ()
diff --git a/compiler/vectorise/Vectorise/Type/TyConDecl.hs b/compiler/vectorise/Vectorise/Type/TyConDecl.hs
index 052eced404..3085beb183 100644
--- a/compiler/vectorise/Vectorise/Type/TyConDecl.hs
+++ b/compiler/vectorise/Vectorise/Type/TyConDecl.hs
@@ -61,10 +61,9 @@ vectTyConDecl tycon name'
        ; cls' <- liftDs $
                    buildClass
                      name'                      -- new name: "V:Class"
-                     (tyConTyVars tycon)        -- keep original type vars
+                     (tyConBinders tycon)       -- keep original kind
                      (map (const Nominal) (tyConRoles tycon)) -- all role are N for safety
                      theta'                     -- superclasses
-                     (tyConBinders tycon)       -- keep original kind
                      (snd . classTvsFds $ cls)  -- keep the original functional dependencies
                      []                         -- no associated types (for the moment)
                      methods'                   -- method info
@@ -105,7 +104,6 @@ vectTyConDecl tycon name'
                     name'                   -- new name
                     (tyConBinders tycon)
                     (tyConResKind tycon)    -- keep original kind
-                    (tyConTyVars tycon)     -- keep original type vars
                     (map (const Nominal) (tyConRoles tycon)) -- all roles are N for safety
                     Nothing
                     []                      -- no stupid theta
@@ -191,7 +189,7 @@ vectDataCon dc
                     (dataConSrcBangs dc)           -- strictness as original constructor
                     (Just $ dataConImplBangs dc)
                     []                             -- no labelled fields for now
-                    univ_tvs univ_bndrs            -- universally quantified vars
+                    univ_bndrs                     -- universally quantified vars
                     []                             -- no existential tvs for now
                     []                             -- no equalities for now
                     []                             -- no context for now
@@ -204,4 +202,4 @@ vectDataCon dc
     rep_arg_tys = dataConRepArgTys dc
     tycon       = dataConTyCon dc
     (univ_tvs, ex_tvs, eq_spec, theta, _arg_tys, _res_ty) = dataConFullSig dc
-    univ_bndrs  = map mkNamedBinder (dataConUnivTyVarBinders dc)
+    univ_bndrs  = dataConUnivTyVarBinders dc