Implement overlapping type family instances.

An ordered, overlapping type family instance is introduced by 'type
instance
where', followed by equations. See the new section in the user manual
(7.7.2.2) for details. The canonical example is Boolean equality at the
type
level:

type family Equals (a :: k) (b :: k) :: Bool
type instance where
  Equals a a = True
  Equals a b = False

A branched family instance, such as this one, checks its equations in
order
and applies only the first the matches. As explained in the note
[Instance
checking within groups] in FamInstEnv.lhs, we must be careful not to
simplify,
say, (Equals Int b) to False, because b might later unify with Int.

This commit includes all of the commits on the overlapping-tyfams
branch. SPJ
requested that I combine all my commits over the past several months
into one
monolithic commit. The following GHC repos are affected: ghc, testsuite,
utils/haddock, libraries/template-haskell, and libraries/dph.

Here are some details for the interested:

- The definition of CoAxiom has been moved from TyCon.lhs to a
  new file CoAxiom.lhs. I made this decision because of the
  number of definitions necessary to support BranchList.

- BranchList is a GADT whose type tracks whether it is a
  singleton list or not-necessarily-a-singleton-list. The reason
  I introduced this type is to increase static checking of places
  where GHC code assumes that a FamInst or CoAxiom is indeed a
  singleton. This assumption takes place roughly 10 times
  throughout the code. I was worried that a future change to GHC
  would invalidate the assumption, and GHC might subtly fail to
  do the right thing. By explicitly labeling CoAxioms and
  FamInsts as being Unbranched (singleton) or
  Branched (not-necessarily-singleton), we make this assumption
  explicit and checkable. Furthermore, to enforce the accuracy of
  this label, the list of branches of a CoAxiom or FamInst is
  stored using a BranchList, whose constructors constrain its
  type index appropriately.

I think that the decision to use BranchList is probably the most
controversial decision I made from a code design point of view.
Although I provide conversions to/from ordinary lists, it is more
efficient to use the brList... functions provided in CoAxiom than
always to convert. The use of these functions does not wander far
from the core CoAxiom/FamInst logic.

BranchLists are motivated and explained in the note [Branched axioms] in
CoAxiom.lhs.

- The CoAxiom type has changed significantly. You can see the new
  type in CoAxiom.lhs. It uses a CoAxBranch type to track
  branches of the CoAxiom. Correspondingly various functions
  producing and consuming CoAxioms had to change, including the
  binary layout of interface files.

- To get branched axioms to work correctly, it is important to have a
  notion
  of type "apartness": two types are apart if they cannot unify, and no
  substitution of variables can ever get them to unify, even after type
family
  simplification. (This is different than the normal failure to unify
because
  of the type family bit.) This notion in encoded in tcApartTys, in
Unify.lhs.
  Because apartness is finer-grained than unification, the tcUnifyTys
now
  calls tcApartTys.

- CoreLinting axioms has been updated, both to reflect the new
  form of CoAxiom and to enforce the apartness rules of branch
  application. The formalization of the new rules is in
  docs/core-spec/core-spec.pdf.

- The FamInst type (in types/FamInstEnv.lhs) has changed
  significantly, paralleling the changes to CoAxiom. Of course,
  this forced minor changes in many files.

- There are several new Notes in FamInstEnv.lhs, including one
  discussing confluent overlap and why we're not doing it.

- lookupFamInstEnv, lookupFamInstEnvConflicts, and
  lookup_fam_inst_env' (the function that actually does the work)
  have all been more-or-less completely rewritten. There is a
  Note [lookup_fam_inst_env' implementation] describing the
  implementation. One of the changes that affects other files is
  to change the type of matches from a pair of (FamInst, [Type])
  to a new datatype (which now includes the index of the matching
  branch). This seemed a better design.

- The TySynInstD constructor in Template Haskell was updated to
  use the new datatype TySynEqn. I also bumped the TH version
  number, requiring changes to DPH cabal files. (That's why the
  DPH repo has an overlapping-tyfams branch.)

- As SPJ requested, I refactored some of the code in HsDecls:

 * splitting up TyDecl into SynDecl and DataDecl, correspondingly
   changing HsTyDefn to HsDataDefn (with only one constructor)

 * splitting FamInstD into TyFamInstD and DataFamInstD and
   splitting FamInstDecl into DataFamInstDecl and TyFamInstDecl

 * making the ClsInstD take a ClsInstDecl, for parallelism with
   InstDecl's other constructors

 * changing constructor TyFamily into FamDecl

 * creating a FamilyDecl type that stores the details for a family
   declaration; this is useful because FamilyDecls can appear in classes
but
   other decls cannot

 * restricting the associated types and associated type defaults for a
 * class
   to be the new, more restrictive types

 * splitting cid_fam_insts into cid_tyfam_insts and cid_datafam_insts,
   according to the new types

 * perhaps one or two more that I'm overlooking

None of these changes has far-reaching implications.

- The user manual, section 7.7.2.2, is updated to describe the new type
  family
  instances.

10 files changed, 217 insertions, 165 deletions

diff --git a/src/Haddock/Backends/Hoogle.hs b/src/Haddock/Backends/Hoogle.hs
index 55f6ac1d..4417dc52 100644
--- a/src/Haddock/Backends/Hoogle.hs
+++ b/src/Haddock/Backends/Hoogle.hs
@@ -112,9 +112,8 @@ operator x = x
 ppExport :: DynFlags -> ExportItem Name -> [String]
 ppExport dflags (ExportDecl decl dc subdocs _) = ppDocumentation dflags (fst dc) ++ f (unL decl)
     where
-        f (TyClD d@TyDecl{})
-            | isDataDecl d      = ppData dflags d subdocs
-            | otherwise         = ppSynonym dflags d
+        f (TyClD d@DataDecl{})  = ppData dflags d subdocs
+        f (TyClD d@SynDecl{})   = ppSynonym dflags d
         f (TyClD d@ClassDecl{}) = ppClass dflags d
         f (ForD (ForeignImport name typ _ _)) = ppSig dflags $ TypeSig [name] typ
         f (ForD (ForeignExport name typ _ _)) = ppSig dflags $ TypeSig [name] typ
@@ -145,8 +144,8 @@ ppClass dflags x = out dflags x{tcdSigs=[]} :
         f (HsForAllTy a b con d) = HsForAllTy a b (reL (context : unLoc con)) d
         f t = HsForAllTy Implicit emptyHsQTvs (reL [context]) (reL t)
 
-        context = nlHsTyConApp (unL $ tcdLName x)
-            (map (reL . HsTyVar . hsTyVarName . unL) (hsQTvBndrs (tcdTyVars x)))
+        context = nlHsTyConApp (tcdName x)
+            (map (reL . HsTyVar . hsTyVarName . unL) (hsQTvBndrs (tyClDeclTyVars x)))
 
 
 ppInstance :: DynFlags -> ClsInst -> [String]
@@ -157,9 +156,9 @@ ppSynonym :: DynFlags -> TyClDecl Name -> [String]
 ppSynonym dflags x = [out dflags x]
 
 ppData :: DynFlags -> TyClDecl Name -> [(Name, DocForDecl Name)] -> [String]
-ppData dflags decl@(TyDecl { tcdTyDefn = defn }) subdocs
-    = showData decl{ tcdTyDefn = defn { td_cons=[],td_derivs=Nothing }} :
-      concatMap (ppCtor dflags decl subdocs . unL) (td_cons defn)
+ppData dflags decl@(DataDecl { tcdDataDefn = defn }) subdocs
+    = showData decl{ tcdDataDefn = defn { dd_cons=[],dd_derivs=Nothing }} :
+      concatMap (ppCtor dflags decl subdocs . unL) (dd_cons defn)
     where
         
         -- GHC gives out "data Bar =", we want to delete the equals
@@ -167,7 +166,7 @@ ppData dflags decl@(TyDecl { tcdTyDefn = defn }) subdocs
         showData d = unwords $ map f $ if last xs == "=" then init xs else xs
             where
                 xs = words $ out dflags d
-                nam = out dflags $ tcdLName d
+                nam = out dflags $ tyClDeclLName d
                 f w = if w == nam then operator nam else w
 ppData _ _ _ = panic "ppData"
 
@@ -196,7 +195,7 @@ ppCtor dflags dat subdocs con = lookupCon dflags subdocs (con_name con)
 
         resType = case con_res con of
             ResTyH98 -> apps $ map (reL . HsTyVar) $ 
-                        unL (tcdLName dat) : [hsTyVarName v | L _ (v@UserTyVar {}) <- hsQTvBndrs $ tcdTyVars dat]
+                        (tcdName dat) : [hsTyVarName v | L _ (v@UserTyVar {}) <- hsQTvBndrs $ tyClDeclTyVars dat]
             ResTyGADT x -> x
 
 
diff --git a/src/Haddock/Backends/LaTeX.hs b/src/Haddock/Backends/LaTeX.hs
index ee304073..6df9062e 100644
--- a/src/Haddock/Backends/LaTeX.hs
+++ b/src/Haddock/Backends/LaTeX.hs
@@ -243,7 +243,7 @@ ppDocGroup lev doc = sec lev <> braces doc
 
 declNames :: LHsDecl DocName -> [DocName]
 declNames (L _ decl) = case decl of
-  TyClD d  -> [unLoc $ tcdLName d]
+  TyClD d  -> [tcdName d]
   SigD (TypeSig lnames _) -> map unLoc lnames
   _ -> error "declaration not supported by declNames"
 
@@ -275,10 +275,10 @@ ppDecl :: LHsDecl DocName
        -> LaTeX
 
 ppDecl (L loc decl) (doc, fnArgsDoc) instances subdocs = case decl of
-  TyClD d@(TyFamily {})          -> ppTyFam False loc doc d unicode
-  TyClD d@(TyDecl{ tcdTyDefn = defn })   
-      | isHsDataDefn defn        -> ppDataDecl instances subdocs loc doc d unicode
-      | otherwise                -> ppTySyn loc (doc, fnArgsDoc) d unicode
+  TyClD d@(FamDecl {})          -> ppTyFam False loc doc d unicode
+  TyClD d@(DataDecl {})   
+                                -> ppDataDecl instances subdocs loc doc d unicode
+  TyClD d@(SynDecl {})          -> ppTySyn loc (doc, fnArgsDoc) d unicode
 -- Family instances happen via FamInst now
 --  TyClD d@(TySynonym {})         
 --    | Just _  <- tcdTyPats d    -> ppTyInst False loc doc d unicode
@@ -311,8 +311,8 @@ ppFor _ _ _ _ =
 -- we skip type patterns for now
 ppTySyn :: SrcSpan -> DocForDecl DocName -> TyClDecl DocName -> Bool -> LaTeX
 
-ppTySyn loc doc (TyDecl { tcdLName = L _ name, tcdTyVars = ltyvars
-                        , tcdTyDefn = TySynonym { td_synRhs = ltype } }) unicode
+ppTySyn loc doc (SynDecl { tcdLName = L _ name, tcdTyVars = ltyvars
+                         , tcdRhs = ltype }) unicode
   = ppTypeOrFunSig loc [name] (unLoc ltype) doc (full, hdr, char '=') unicode
   where
     hdr  = hsep (keyword "type" : ppDocBinder name : ppTyVars ltyvars)
@@ -549,7 +549,7 @@ ppDataDecl instances subdocs _loc doc dataDecl unicode
    $$ instancesBit
 
   where
-    cons      = td_cons (tcdTyDefn dataDecl)
+    cons      = dd_cons (tcdDataDefn dataDecl)
     resTy     = (con_res . unLoc . head) cons
 
     body = catMaybes [constrBit, documentationToLaTeX doc]
@@ -694,8 +694,8 @@ ppSideBySideField subdocs unicode (ConDeclField (L _ name) ltype _) =
 -- | Print the LHS of a data\/newtype declaration.
 -- Currently doesn't handle 'data instance' decls or kind signatures
 ppDataHeader :: TyClDecl DocName -> Bool -> LaTeX
-ppDataHeader (TyDecl { tcdLName = L _ name, tcdTyVars = tyvars
-                     , tcdTyDefn = TyData { td_ND = nd, td_ctxt = ctxt } }) unicode
+ppDataHeader (DataDecl { tcdLName = L _ name, tcdTyVars = tyvars
+                       , tcdDataDefn = HsDataDefn { dd_ND = nd, dd_ctxt = ctxt } }) unicode
   = -- newtype or data
     (case nd of { NewType -> keyword "newtype"; DataType -> keyword "data" }) <+>
     -- context
diff --git a/src/Haddock/Backends/Xhtml.hs b/src/Haddock/Backends/Xhtml.hs
index c68b7cbc..3251477a 100644
--- a/src/Haddock/Backends/Xhtml.hs
+++ b/src/Haddock/Backends/Xhtml.hs
@@ -556,10 +556,10 @@ processForMiniSynopsis :: Module -> Bool -> Qualification -> ExportItem DocName
 processForMiniSynopsis mdl unicode qual (ExportDecl (L _loc decl0) _doc _ _insts) =
   ((divTopDecl <<).(declElem <<)) `fmap` case decl0 of
     TyClD d -> let b = ppTyClBinderWithVarsMini mdl d in case d of
-        (TyFamily{}) -> [ppTyFamHeader True False d unicode qual]
-        (TyDecl{ tcdTyDefn = TyData {} }) -> [keyword "data" <+> b]
-        (TyDecl{ tcdTyDefn = TySynonym {} }) -> [keyword "type" <+> b]
-        (ClassDecl {})    -> [keyword "class" <+> b]
+        (FamDecl decl)    -> [ppTyFamHeader True False decl unicode qual]
+        (DataDecl{})   -> [keyword "data" <+> b]
+        (SynDecl{})    -> [keyword "type" <+> b]
+        (ClassDecl {}) -> [keyword "class" <+> b]
         _ -> []
     SigD (TypeSig lnames (L _ _)) ->
       map (ppNameMini mdl . nameOccName . getName . unLoc) lnames
@@ -578,8 +578,8 @@ ppNameMini mdl nm =
 
 ppTyClBinderWithVarsMini :: Module -> TyClDecl DocName -> Html
 ppTyClBinderWithVarsMini mdl decl =
-  let n = unLoc $ tcdLName decl
-      ns = tyvarNames $ tcdTyVars decl
+  let n = tcdName decl
+      ns = tyvarNames $ tcdTyVars decl -- it's safe to use tcdTyVars, see code above
   in ppTypeApp n ns (ppNameMini mdl . nameOccName . getName) ppTyName
 
 
diff --git a/src/Haddock/Backends/Xhtml/Decl.hs b/src/Haddock/Backends/Xhtml/Decl.hs
index 59be34f7..db39ccca 100644
--- a/src/Haddock/Backends/Xhtml/Decl.hs
+++ b/src/Haddock/Backends/Xhtml/Decl.hs
@@ -39,10 +39,9 @@ ppDecl :: Bool -> LinksInfo -> LHsDecl DocName ->
           DocForDecl DocName -> [DocInstance DocName] -> [(DocName, DocForDecl DocName)] ->
           Bool -> Qualification -> Html
 ppDecl summ links (L loc decl) (mbDoc, fnArgsDoc) instances subdocs unicode qual = case decl of
-  TyClD d@(TyFamily {})          -> ppTyFam summ False links loc mbDoc d unicode qual
-  TyClD d@(TyDecl{ tcdTyDefn = defn })   
-      | isHsDataDefn defn        -> ppDataDecl summ links instances subdocs loc mbDoc d unicode qual
-      | otherwise                -> ppTySyn summ links loc (mbDoc, fnArgsDoc) d unicode qual
+  TyClD (FamDecl d)              -> ppTyFam summ False links loc mbDoc d unicode qual
+  TyClD d@(DataDecl {})          -> ppDataDecl summ links instances subdocs loc mbDoc d unicode qual
+  TyClD d@(SynDecl {})           -> ppTySyn summ links loc (mbDoc, fnArgsDoc) d unicode qual
   TyClD d@(ClassDecl {})         -> ppClassDecl summ links instances loc mbDoc subdocs d unicode qual
   SigD (TypeSig lnames (L _ t))  -> ppFunSig summ links loc (mbDoc, fnArgsDoc) (map unLoc lnames) t unicode qual
   ForD d                         -> ppFor summ links loc (mbDoc, fnArgsDoc) d unicode qual
@@ -115,8 +114,8 @@ ppFor _ _ _ _ _ _ _ = error "ppFor"
 -- we skip type patterns for now
 ppTySyn :: Bool -> LinksInfo -> SrcSpan -> DocForDecl DocName -> TyClDecl DocName -> Bool
         -> Qualification -> Html
-ppTySyn summary links loc doc (TyDecl { tcdLName = L _ name, tcdTyVars = ltyvars
-                                      , tcdTyDefn = TySynonym { td_synRhs = ltype } }) 
+ppTySyn summary links loc doc (SynDecl { tcdLName = L _ name, tcdTyVars = ltyvars
+                                       , tcdRhs = ltype }) 
         unicode qual
   = ppTypeOrFunSig summary links loc [name] (unLoc ltype) doc
                    (full, hdr, spaceHtml +++ equals) unicode qual
@@ -145,10 +144,10 @@ ppTyName name
 --------------------------------------------------------------------------------
 
 
-ppTyFamHeader :: Bool -> Bool -> TyClDecl DocName -> Bool -> Qualification -> Html
-ppTyFamHeader summary associated decl unicode qual =
-
-  (case tcdFlavour decl of
+ppTyFamHeader :: Bool -> Bool -> FamilyDecl DocName -> Bool -> Qualification -> Html
+ppTyFamHeader summary associated d@(FamilyDecl { fdFlavour = flav
+                                               , fdKindSig = mkind }) unicode qual =
+  (case flav of
      TypeFamily
        | associated -> keyword "type"
        | otherwise  -> keyword "type family"
@@ -157,22 +156,22 @@ ppTyFamHeader summary associated decl unicode qual =
        | otherwise  -> keyword "data family"
   ) <+>
 
-  ppTyClBinderWithVars summary decl <+>
+  ppFamDeclBinderWithVars summary d <+>
 
-  case tcdKindSig decl of
+  case mkind of
     Just kind -> dcolon unicode  <+> ppLKind unicode qual kind
     Nothing   -> noHtml
 
 
 ppTyFam :: Bool -> Bool -> LinksInfo -> SrcSpan -> Documentation DocName ->
-              TyClDecl DocName -> Bool -> Qualification -> Html
+              FamilyDecl DocName -> Bool -> Qualification -> Html
 ppTyFam summary associated links loc doc decl unicode qual
 
   | summary   = ppTyFamHeader True associated decl unicode qual
   | otherwise = header_ +++ docSection qual doc +++ instancesBit
 
   where
-    docname = tcdName decl
+    docname = unLoc $ fdLName decl
 
     header_ = topDeclElem links loc [docname] (ppTyFamHeader summary associated decl unicode qual)
 
@@ -187,23 +186,25 @@ ppTyFam summary associated links loc doc decl unicode qual
 --------------------------------------------------------------------------------
 
 
-ppAssocType :: Bool -> LinksInfo -> DocForDecl DocName -> LTyClDecl DocName -> Bool
+ppAssocType :: Bool -> LinksInfo -> DocForDecl DocName -> LFamilyDecl DocName -> Bool
             -> Qualification -> Html
 ppAssocType summ links doc (L loc decl) unicode qual =
-  case decl of
-    TyFamily  {} -> ppTyFam summ True links loc (fst doc) decl unicode qual
-    _            -> error "declaration type not supported by ppAssocType"
+   ppTyFam summ True links loc (fst doc) decl unicode qual
 
 
 --------------------------------------------------------------------------------
 -- * TyClDecl helpers
 --------------------------------------------------------------------------------
 
+-- | Print a type family and its variables 
+ppFamDeclBinderWithVars :: Bool -> FamilyDecl DocName -> Html
+ppFamDeclBinderWithVars summ (FamilyDecl { fdLName = lname, fdTyVars = tvs }) =
+  ppAppDocNameNames summ (unLoc lname) (tyvarNames tvs)
 
--- | Print a type family / newtype / data / class binder and its variables 
-ppTyClBinderWithVars :: Bool -> TyClDecl DocName -> Html
-ppTyClBinderWithVars summ decl =
-  ppAppDocNameNames summ (unLoc $ tcdLName decl) (tyvarNames $ tcdTyVars decl)
+-- | Print a newtype / data binder and its variables 
+ppDataBinderWithVars :: Bool -> TyClDecl DocName -> Html
+ppDataBinderWithVars summ decl =
+  ppAppDocNameNames summ (tcdName decl) (tyvarNames $ tcdTyVars decl)
 
 
 --------------------------------------------------------------------------------
@@ -303,7 +304,7 @@ ppShortClassDecl summary links (ClassDecl { tcdCtxt = lctxt, tcdLName = lname, t
       +++ shortSubDecls
           (
             [ ppAssocType summary links doc at unicode qual | at <- ats
-              , let doc = lookupAnySubdoc (tcdName $ unL at) subdocs ]  ++
+              , let doc = lookupAnySubdoc (unL $ fdLName $ unL at) subdocs ]  ++
 
                 -- ToDo: add associated type defaults
 
@@ -336,14 +337,14 @@ ppClassDecl summary links instances loc d subdocs
       | null lsigs = topDeclElem links loc [nm] (hdr unicode qual)
       | otherwise  = topDeclElem links loc [nm] (hdr unicode qual <+> keyword "where")
 
-    nm   = unLoc $ tcdLName decl
+    nm   = tcdName decl
 
     hdr = ppClassHdr summary lctxt (unLoc lname) ltyvars lfds
 
     -- ToDo: add assocatied typ defaults
     atBit = subAssociatedTypes [ ppAssocType summary links doc at unicode qual
                       | at <- ats
-                      , let doc = lookupAnySubdoc (tcdName $ unL at) subdocs ]
+                      , let doc = lookupAnySubdoc (unL $ fdLName $ unL at) subdocs ]
 
     methodBit = subMethods [ ppFunSig summary links loc doc names typ unicode qual
                            | L _ (TypeSig lnames (L _ typ)) <- lsigs
@@ -401,7 +402,7 @@ ppShortDataDecl summary _links _loc dataDecl unicode qual
     doConstr c con = toHtml [c] <+> ppShortConstr summary (unLoc con) unicode qual
     doGADTConstr con = ppShortConstr summary (unLoc con) unicode qual
 
-    cons      = td_cons (tcdTyDefn dataDecl)
+    cons      = dd_cons (tcdDataDefn dataDecl)
     resTy     = (con_res . unLoc . head) cons
 
 
@@ -415,8 +416,8 @@ ppDataDecl summary links instances subdocs loc doc dataDecl unicode qual
   | otherwise = header_ +++ docSection qual doc +++ constrBit +++ instancesBit
 
   where
-    docname   = unLoc . tcdLName $ dataDecl
-    cons      = td_cons (tcdTyDefn dataDecl)
+    docname   = tcdName dataDecl
+    cons      = dd_cons (tcdDataDefn dataDecl)
     resTy     = (con_res . unLoc . head) cons
 
     header_ = topDeclElem links loc [docname] (ppDataHeader summary dataDecl unicode qual
@@ -570,14 +571,15 @@ ppShortField summary unicode qual (ConDeclField (L _ name) ltype _)
 -- | Print the LHS of a data\/newtype declaration.
 -- Currently doesn't handle 'data instance' decls or kind signatures
 ppDataHeader :: Bool -> TyClDecl DocName -> Bool -> Qualification -> Html
-ppDataHeader summary decl@(TyDecl { tcdTyDefn = TyData { td_ND = nd, td_ctxt = ctxt } }) 
+ppDataHeader summary decl@(DataDecl { tcdDataDefn = HsDataDefn { dd_ND = nd
+                                                               , dd_ctxt = ctxt } }) 
              unicode qual
   = -- newtype or data
     (case nd of { NewType -> keyword "newtype"; DataType -> keyword "data" }) <+>
     -- context
     ppLContext ctxt unicode qual <+>
     -- T a b c ..., or a :+: b
-    ppTyClBinderWithVars summary decl
+    ppDataBinderWithVars summary decl
 ppDataHeader _ _ _ _ = error "ppDataHeader: illegal argument"
 
 
diff --git a/src/Haddock/Convert.hs b/src/Haddock/Convert.hs
index aca12188..8894793d 100644
--- a/src/Haddock/Convert.hs
+++ b/src/Haddock/Convert.hs
@@ -18,7 +18,7 @@ module Haddock.Convert where
 
 
 import HsSyn
-import TcType ( tcSplitTyConApp_maybe, tcSplitSigmaTy )
+import TcType ( tcSplitSigmaTy )
 import TypeRep
 import Type(isStrLitTy)
 import Kind ( splitKindFunTys, synTyConResKind )
@@ -26,6 +26,7 @@ import Name
 import Var
 import Class
 import TyCon
+import CoAxiom
 import DataCon
 import BasicTypes ( TupleSort(..) )
 import TysPrim ( alphaTyVars )
@@ -53,7 +54,14 @@ tyThingToLHsDecl t = noLoc $ case t of
   -- later in the file (also it's used for class associated-types too.)
   ATyCon tc
     | Just cl <- tyConClass_maybe tc -- classes are just a little tedious
-    -> TyClD $ ClassDecl
+    -> let extractFamilyDecl :: TyClDecl a -> LFamilyDecl a
+           extractFamilyDecl (FamDecl d) = noLoc d
+           extractFamilyDecl _           =
+             error "tyThingToLHsDecl: impossible associated tycon"
+
+           atTyClDecls = [synifyTyCon at_tc | (at_tc, _) <- classATItems cl]
+           atFamDecls  = map extractFamilyDecl atTyClDecls in
+       TyClD $ ClassDecl
          { tcdCtxt = synifyCtx (classSCTheta cl)
          , tcdLName = synifyName cl
          , tcdTyVars = synifyTyVars (classTyVars cl)
@@ -64,7 +72,7 @@ tyThingToLHsDecl t = noLoc $ case t of
                          (classMethods cl)
          , tcdMeths = emptyBag --ignore default method definitions, they don't affect signature
          -- class associated-types are a subset of TyCon:
-         , tcdATs = [noLoc (synifyTyCon at_tc) | (at_tc, _) <- classATItems cl]
+         , tcdATs = atFamDecls
          , tcdATDefs = [] --ignore associated type defaults
          , tcdDocs = [] --we don't have any docs at this point
          , tcdFVs = placeHolderNames }
@@ -73,36 +81,40 @@ tyThingToLHsDecl t = noLoc $ case t of
 
   -- type-constructors (e.g. Maybe) are complicated, put the definition
   -- later in the file (also it's used for class associated-types too.)
-  ACoAxiom ax -> InstD (FamInstD { lid_inst = synifyAxiom ax })
+  ACoAxiom ax -> InstD (TyFamInstD { tfid_inst = synifyAxiom ax })
 
   -- a data-constructor alone just gets rendered as a function:
   ADataCon dc -> SigD (TypeSig [synifyName dc]
     (synifyType ImplicitizeForAll (dataConUserType dc)))
 
-synifyATDefault :: TyCon -> LFamInstDecl Name
+synifyATDefault :: TyCon -> LTyFamInstDecl Name
 synifyATDefault tc = noLoc (synifyAxiom ax)
   where Just ax = tyConFamilyCoercion_maybe tc
 
-synifyAxiom :: CoAxiom -> FamInstDecl Name
-synifyAxiom (CoAxiom { co_ax_tvs = tkvs, co_ax_lhs = lhs, co_ax_rhs = rhs })
-  | Just (tc, args) <- tcSplitTyConApp_maybe lhs
-  = let name      = synifyName tc
-        typats    = map (synifyType WithinType) args
-        hs_rhs_ty = synifyType WithinType rhs
+synifyAxBranch :: TyCon -> CoAxBranch -> TyFamInstEqn Name
+synifyAxBranch tc (CoAxBranch { cab_tvs = tkvs, cab_lhs = args, cab_rhs = rhs })
+  = let name       = synifyName tc
+        typats     = map (synifyType WithinType) args
+        hs_rhs     = synifyType WithinType rhs
         (kvs, tvs) = partition isKindVar tkvs
-    in FamInstDecl { fid_tycon = name 
-                   , fid_pats = HsWB { hswb_cts = typats
-                                     , hswb_kvs = map tyVarName kvs
-                                     , hswb_tvs = map tyVarName tvs }
-                   , fid_defn = TySynonym hs_rhs_ty, fid_fvs = placeHolderNames }
-  | otherwise
-  = error "synifyAxiom" 
+    in TyFamInstEqn { tfie_tycon = name
+                    , tfie_pats  = HsWB { hswb_cts = typats
+                                        , hswb_kvs = map tyVarName kvs
+                                        , hswb_tvs = map tyVarName tvs }
+                    , tfie_rhs   = hs_rhs }
+
+synifyAxiom :: CoAxiom br -> TyFamInstDecl Name
+synifyAxiom (CoAxiom { co_ax_tc = tc, co_ax_branches = branches })
+  = let eqns = brListMap (noLoc . synifyAxBranch tc) branches
+    in TyFamInstDecl { tfid_eqns  = eqns
+                     , tfid_group = (brListLength branches /= 1)
+                     , tfid_fvs   = placeHolderNames }
 
 synifyTyCon :: TyCon -> TyClDecl Name
 synifyTyCon tc
   | isFunTyCon tc || isPrimTyCon tc 
-  = TyDecl { tcdLName = synifyName tc
-           , tcdTyVars =       -- tyConTyVars doesn't work on fun/prim, but we can make them up:
+  = DataDecl { tcdLName = synifyName tc
+             , tcdTyVars =       -- tyConTyVars doesn't work on fun/prim, but we can make them up:
                          let mk_hs_tv realKind fakeTyVar 
                                 = noLoc $ KindedTyVar (getName fakeTyVar) 
                                                       (synifyKindSig realKind)
@@ -111,37 +123,44 @@ synifyTyCon tc
                                                                 alphaTyVars --a, b, c... which are unfortunately all kind *
                                    }
                             
-           , tcdTyDefn = TyData { td_ND = DataType  -- arbitrary lie, they are neither 
+           , tcdDataDefn = HsDataDefn { dd_ND = DataType  -- arbitrary lie, they are neither 
                                                     -- algebraic data nor newtype:
-                                , td_ctxt = noLoc []
-                                , td_cType = Nothing
-                                , td_kindSig = Just (synifyKindSig (tyConKind tc))
+                                      , dd_ctxt = noLoc []
+                                      , dd_cType = Nothing
+                                      , dd_kindSig = Just (synifyKindSig (tyConKind tc))
                                                -- we have their kind accurately:
-                                , td_cons = []  -- No constructors
-                                , td_derivs = Nothing }
+                                      , dd_cons = []  -- No constructors
+                                      , dd_derivs = Nothing }
            , tcdFVs = placeHolderNames }
   | isSynFamilyTyCon tc 
-  = TyFamily TypeFamily (synifyName tc) (synifyTyVars (tyConTyVars tc))
-               (Just (synifyKindSig (synTyConResKind tc)))
+  = case synTyConRhs_maybe tc of
+        Just (SynFamilyTyCon {}) ->
+          FamDecl (FamilyDecl TypeFamily (synifyName tc) (synifyTyVars (tyConTyVars tc))
+                              (Just (synifyKindSig (synTyConResKind tc))))
+        _ -> error "synifyTyCon: impossible open type synonym?"
   | isDataFamilyTyCon tc 
   = --(why no "isOpenAlgTyCon"?)
     case algTyConRhs tc of
         DataFamilyTyCon ->
-          TyFamily DataFamily (synifyName tc) (synifyTyVars (tyConTyVars tc))
-               Nothing --always kind '*'
-               -- placeHolderKind
+          FamDecl (FamilyDecl DataFamily (synifyName tc) (synifyTyVars (tyConTyVars tc))
+                              Nothing) --always kind '*'
         _ -> error "synifyTyCon: impossible open data type?"
+  | isSynTyCon tc
+  = case synTyConRhs_maybe tc of
+        Just (SynonymTyCon ty) ->
+          SynDecl { tcdLName = synifyName tc
+                  , tcdTyVars = synifyTyVars (tyConTyVars tc)
+                  , tcdRhs = synifyType WithinType ty
+                  , tcdFVs = placeHolderNames }
+        _ -> error "synifyTyCon: impossible synTyCon"
   | otherwise =
-  -- (closed) type, newtype, and data
+  -- (closed) newtype and data
   let
-  -- alg_ only applies to newtype/data
-  -- syn_ only applies to type
-  -- others apply to both
   alg_nd = if isNewTyCon tc then NewType else DataType
   alg_ctx = synifyCtx (tyConStupidTheta tc)
   name = synifyName tc
   tyvars = synifyTyVars (tyConTyVars tc)
-  alg_kindSig = Just (tyConKind tc)
+  kindSig = Just (tyConKind tc)
   -- The data constructors.
   --
   -- Any data-constructors not exported from the module that *defines* the
@@ -158,19 +177,18 @@ synifyTyCon tc
   -- That seems like an acceptable compromise (they'll just be documented
   -- in prefix position), since, otherwise, the logic (at best) gets much more
   -- complicated. (would use dataConIsInfix.)
-  alg_use_gadt_syntax = any (not . isVanillaDataCon) (tyConDataCons tc)
-  alg_cons = map (synifyDataCon alg_use_gadt_syntax) (tyConDataCons tc)
+  use_gadt_syntax = any (not . isVanillaDataCon) (tyConDataCons tc)
+  cons = map (synifyDataCon use_gadt_syntax) (tyConDataCons tc)
   -- "deriving" doesn't affect the signature, no need to specify any.
   alg_deriv = Nothing
-  defn | Just (_, syn_rhs) <- synTyConDefn_maybe tc 
-       = TySynonym (synifyType WithinType syn_rhs)
-       | otherwise = TyData { td_ND = alg_nd, td_ctxt = alg_ctx
-                            , td_cType = Nothing
-                            , td_kindSig = fmap synifyKindSig alg_kindSig
-                            , td_cons    = alg_cons 
-                            , td_derivs  = alg_deriv }
- in TyDecl { tcdLName = name, tcdTyVars = tyvars, tcdTyDefn = defn
-           , tcdFVs = placeHolderNames }
+  defn = HsDataDefn { dd_ND      = alg_nd
+                    , dd_ctxt    = alg_ctx
+                    , dd_cType   = Nothing
+                    , dd_kindSig = fmap synifyKindSig kindSig
+                    , dd_cons    = cons 
+                    , dd_derivs  = alg_deriv }
+ in DataDecl { tcdLName = name, tcdTyVars = tyvars, tcdDataDefn = defn
+             , tcdFVs = placeHolderNames }
 
 -- User beware: it is your responsibility to pass True (use_gadt_syntax)
 -- for any constructor that would be misrepresented by omitting its
diff --git a/src/Haddock/GhcUtils.hs b/src/Haddock/GhcUtils.hs
index a841e567..82ccb590 100644
--- a/src/Haddock/GhcUtils.hs
+++ b/src/Haddock/GhcUtils.hs
@@ -147,7 +147,7 @@ isValD _ = False
 
 
 declATs :: HsDecl a -> [a]
-declATs (TyClD d) | isClassDecl d = map (tcdName . unL) $ tcdATs d
+declATs (TyClD d) | isClassDecl d = map (unL . fdLName . unL) $ tcdATs d
 declATs _ = []
 
 
@@ -215,9 +215,9 @@ instance Parent (ConDecl Name) where
 
 instance Parent (TyClDecl Name) where
   children d
-    | isDataDecl  d = map (unL . con_name . unL) . td_cons . tcdTyDefn $ d
+    | isDataDecl  d = map (unL . con_name . unL) . dd_cons . tcdDataDefn $ d
     | isClassDecl d =
-        map (tcdName . unL) (tcdATs d) ++
+        map (unL . fdLName . unL) (tcdATs d) ++
         [ unL n | L _ (TypeSig ns _) <- tcdSigs d, n <- ns ]
     | otherwise = []
 
@@ -231,8 +231,8 @@ family = getName &&& children
 -- child to its grand-children, recursively.
 families :: TyClDecl Name -> [(Name, [Name])]
 families d
-  | isDataDecl  d = family d : map (family . unL) (td_cons (tcdTyDefn d))
-  | isClassDecl d = family d : concatMap (families . unL) (tcdATs d)
+  | isDataDecl  d = family d : map (family . unL) (dd_cons (tcdDataDefn d))
+  | isClassDecl d = [family d]
   | otherwise     = []
 
 
diff --git a/src/Haddock/Interface/AttachInstances.hs b/src/Haddock/Interface/AttachInstances.hs
index a4d4764e..86d1a7b8 100644
--- a/src/Haddock/Interface/AttachInstances.hs
+++ b/src/Haddock/Interface/AttachInstances.hs
@@ -53,7 +53,7 @@ attachToExportItem :: Interface -> IfaceMap -> InstIfaceMap -> ExportItem Name -
 attachToExportItem iface ifaceMap instIfaceMap export =
   case export of
     ExportDecl { expItemDecl = L _ (TyClD d) } -> do
-      mb_info <- getAllInfo (unLoc (tcdLName d))
+      mb_info <- getAllInfo (tcdName d)
       let export' =
             export {
               expItemInstances =
diff --git a/src/Haddock/Interface/Create.hs b/src/Haddock/Interface/Create.hs
index 9fca453d..8f429d9c 100644
--- a/src/Haddock/Interface/Create.hs
+++ b/src/Haddock/Interface/Create.hs
@@ -268,7 +268,7 @@ mkMaps dflags gre instances decls = do
     instanceMap = M.fromList [ (getSrcSpan n, n) | i <- instances, let n = getName i ]
 
     names :: HsDecl Name -> [Name]
-    names (InstD (ClsInstD { cid_poly_ty = L l _ })) = maybeToList (M.lookup l instanceMap)  -- See note [2].
+    names (InstD (ClsInstD (ClsInstDecl { cid_poly_ty = L l _ }))) = maybeToList (M.lookup l instanceMap)  -- See note [2].
     names decl = getMainDeclBinder decl
 
 -- Note [2]:
@@ -296,7 +296,7 @@ subordinates (TyClD decl)
                 ]
     dataSubs = constrs ++ fields
       where
-        cons = map unL $ (td_cons (tcdTyDefn decl))
+        cons = map unL $ (dd_cons (tcdDataDefn decl))
         constrs = [ (unL $ con_name c, maybeToList $ fmap unL $ con_doc c, M.empty)
                   | c <- cons ]
         fields  = [ (unL n, maybeToList $ fmap unL doc, M.empty)
@@ -312,7 +312,7 @@ typeDocs d =
   case d of
     SigD (TypeSig _ ty) -> docs (unLoc ty)
     ForD (ForeignImport _ ty _ _) -> docs (unLoc ty)
-    TyClD (TyDecl { tcdTyDefn = TySynonym {td_synRhs = ty}}) -> docs (unLoc ty)
+    TyClD (SynDecl { tcdRhs = ty }) -> docs (unLoc ty)
     _ -> M.empty
   where
     go n (HsForAllTy _ _ _ ty) = go n (unLoc ty)
@@ -331,7 +331,7 @@ classDecls class_ = filterDecls . collectDocs . sortByLoc $ decls
     docs  = mkDecls tcdDocs DocD class_
     defs  = mkDecls (bagToList . tcdMeths) ValD class_
     sigs  = mkDecls tcdSigs SigD class_
-    ats   = mkDecls tcdATs TyClD class_
+    ats   = mkDecls tcdATs (TyClD . FamDecl) class_
 
 
 -- | The top-level declarations of a module that we care about,
@@ -374,7 +374,11 @@ warnAboutFilteredDecls :: DynFlags -> Module -> [LHsDecl Name] -> ErrMsgM ()
 warnAboutFilteredDecls dflags mdl decls = do
   let modStr = moduleString mdl
   let typeInstances =
-        nub [ unLoc (fid_tycon d) | L _ (InstD (FamInstD { lid_inst = d })) <- decls ]
+        nub (concat [[ unLoc (tfie_tycon eqn)
+                     | L _ (InstD (TyFamInstD (TyFamInstDecl { tfid_eqns = eqns }))) <- decls
+                     , L _ eqn <- eqns ],
+                     [ unLoc (dfid_tycon d)
+                     | L _ (InstD (DataFamInstD { dfid_inst = d })) <- decls ]])
 
   unless (null typeInstances) $
     tell [
@@ -383,8 +387,11 @@ warnAboutFilteredDecls dflags mdl decls = do
       ++ "will be filtered out:\n  " ++ (intercalate ", "
       $ map (occNameString . nameOccName) typeInstances) ]
 
-  let instances = nub [ pretty dflags i | L _ (InstD (ClsInstD { cid_poly_ty = i, cid_fam_insts = ats })) <- decls
-                                 , not (null ats) ]
+  let instances = nub [ pretty dflags i | L _ (InstD (ClsInstD (ClsInstDecl
+                                                { cid_poly_ty = i
+                                                , cid_tyfam_insts = ats
+                                                , cid_datafam_insts = adts }))) <- decls
+                                 , not (null ats) || not (null adts) ]
 
   unless (null instances) $
     tell [
@@ -734,11 +741,11 @@ extractDecl name mdl decl
           _ -> error "internal: extractDecl"
       TyClD d | isDataDecl d ->
         let (n, tyvar_names) = name_and_tyvars d
-            L pos sig = extractRecSel name mdl n tyvar_names (td_cons (tcdTyDefn d))
+            L pos sig = extractRecSel name mdl n tyvar_names (dd_cons (tcdDataDefn d))
         in L pos (SigD sig)
       _ -> error "internal: extractDecl"
   where
-    name_and_tyvars d = (unLoc (tcdLName d), hsLTyVarLocNames (tcdTyVars d))
+    name_and_tyvars d = (tcdName d, hsLTyVarLocNames (tyClDeclTyVars d))
 
 
 toTypeNoLoc :: Located Name -> LHsType Name
diff --git a/src/Haddock/Interface/Rename.hs b/src/Haddock/Interface/Rename.hs
index 6109c341..b384886c 100644
--- a/src/Haddock/Interface/Rename.hs
+++ b/src/Haddock/Interface/Rename.hs
@@ -322,10 +322,8 @@ renameDecl decl = case decl of
     return (InstD d')
   _ -> error "renameDecl"
 
-
-renameLTyClD :: LTyClDecl Name -> RnM (LTyClDecl DocName)
-renameLTyClD (L loc d) = return . L loc =<< renameTyClD d
-
+renameLThing :: (a Name -> RnM (a DocName)) -> Located (a Name) -> RnM (Located (a DocName))
+renameLThing fn (L loc x) = return . L loc =<< fn x
 
 renameTyClD :: TyClDecl Name -> RnM (TyClDecl DocName)
 renameTyClD d = case d of
@@ -334,19 +332,21 @@ renameTyClD d = case d of
     return (ForeignType lname' b)
 
 --  TyFamily flav lname ltyvars kind tckind -> do
-  TyFamily flav lname ltyvars tckind -> do
-    lname'   <- renameL lname
-    ltyvars' <- renameLTyVarBndrs ltyvars
---    kind'    <- renameMaybeLKind kind
-    tckind'    <- renameMaybeLKind tckind
---    return (TyFamily flav lname' ltyvars' kind' tckind)
-    return (TyFamily flav lname' ltyvars' tckind')
+  FamDecl { tcdFam = decl } -> do
+    decl' <- renameFamilyDecl decl
+    return (FamDecl { tcdFam = decl' })
+
+  SynDecl { tcdLName = lname, tcdTyVars = tyvars, tcdRhs = rhs, tcdFVs = fvs } -> do
+    lname'    <- renameL lname
+    tyvars'   <- renameLTyVarBndrs tyvars
+    rhs'     <- renameLType rhs
+    return (SynDecl { tcdLName = lname', tcdTyVars = tyvars', tcdRhs = rhs', tcdFVs = fvs })
 
-  TyDecl { tcdLName = lname, tcdTyVars = tyvars, tcdTyDefn = defn, tcdFVs = fvs } -> do
+  DataDecl { tcdLName = lname, tcdTyVars = tyvars, tcdDataDefn = defn, tcdFVs = fvs } -> do
     lname'    <- renameL lname
     tyvars'   <- renameLTyVarBndrs tyvars
-    defn'     <- renameTyDefn defn
-    return (TyDecl { tcdLName = lname', tcdTyVars = tyvars', tcdTyDefn = defn', tcdFVs = fvs })
+    defn'     <- renameDataDefn defn
+    return (DataDecl { tcdLName = lname', tcdTyVars = tyvars', tcdDataDefn = defn', tcdFVs = fvs })
 
   ClassDecl { tcdCtxt = lcontext, tcdLName = lname, tcdTyVars = ltyvars
             , tcdFDs = lfundeps, tcdSigs = lsigs, tcdATs = ats, tcdATDefs = at_defs } -> do
@@ -355,8 +355,8 @@ renameTyClD d = case d of
     ltyvars'  <- renameLTyVarBndrs ltyvars
     lfundeps' <- mapM renameLFunDep lfundeps
     lsigs'    <- mapM renameLSig lsigs
-    ats'      <- mapM renameLTyClD ats
-    at_defs'  <- mapM (mapM renameFamInstD) at_defs
+    ats'      <- mapM (renameLThing renameFamilyDecl) ats
+    at_defs'  <- mapM (mapM renameTyFamInstD) at_defs
     -- we don't need the default methods or the already collected doc entities
     return (ClassDecl { tcdCtxt = lcontext', tcdLName = lname', tcdTyVars = ltyvars'
                       , tcdFDs = lfundeps', tcdSigs = lsigs', tcdMeths= emptyBag
@@ -370,19 +370,24 @@ renameTyClD d = case d of
 
     renameLSig (L loc sig) = return . L loc =<< renameSig sig
 
-renameTyDefn :: HsTyDefn Name -> RnM (HsTyDefn DocName)
-renameTyDefn (TyData { td_ND = nd, td_ctxt = lcontext, td_cType = cType
-                     , td_kindSig = k, td_cons = cons }) = do
+renameFamilyDecl :: FamilyDecl Name -> RnM (FamilyDecl DocName)
+renameFamilyDecl (FamilyDecl { fdFlavour = flav, fdLName = lname
+                             , fdTyVars = ltyvars, fdKindSig = tckind }) = do
+    lname'   <- renameL lname
+    ltyvars' <- renameLTyVarBndrs ltyvars
+    tckind'  <- renameMaybeLKind tckind
+    return (FamilyDecl { fdFlavour = flav, fdLName = lname'
+                       , fdTyVars = ltyvars', fdKindSig = tckind' })
+
+renameDataDefn :: HsDataDefn Name -> RnM (HsDataDefn DocName)
+renameDataDefn (HsDataDefn { dd_ND = nd, dd_ctxt = lcontext, dd_cType = cType
+                           , dd_kindSig = k, dd_cons = cons }) = do
     lcontext' <- renameLContext lcontext
     k'        <- renameMaybeLKind k
     cons'     <- mapM (mapM renameCon) cons
     -- I don't think we need the derivings, so we return Nothing
-    return (TyData { td_ND = nd, td_ctxt = lcontext', td_cType = cType
-                   , td_kindSig = k', td_cons = cons', td_derivs = Nothing })
-
-renameTyDefn (TySynonym { td_synRhs = ltype }) = do
-    ltype'   <- renameLType ltype
-    return (TySynonym { td_synRhs = ltype' })
+    return (HsDataDefn { dd_ND = nd, dd_ctxt = lcontext', dd_cType = cType
+                       , dd_kindSig = k', dd_cons = cons', dd_derivs = Nothing })
 
 renameCon :: ConDecl Name -> RnM (ConDecl DocName)
 renameCon decl@(ConDecl { con_name = lname, con_qvars = ltyvars
@@ -435,24 +440,47 @@ renameForD (ForeignExport lname ltype co x) = do
 
 
 renameInstD :: InstDecl Name -> RnM (InstDecl DocName)
-renameInstD (ClsInstD { cid_poly_ty =ltype, cid_fam_insts = lATs }) = do
+renameInstD (ClsInstD { cid_inst = d }) = do
+  d' <- renameClsInstD d
+  return (ClsInstD { cid_inst = d' })
+renameInstD (TyFamInstD { tfid_inst = d }) = do
+  d' <- renameTyFamInstD d
+  return (TyFamInstD { tfid_inst = d' })
+renameInstD (DataFamInstD { dfid_inst = d }) = do
+  d' <- renameDataFamInstD d
+  return (DataFamInstD { dfid_inst = d' })
+
+renameClsInstD :: ClsInstDecl Name -> RnM (ClsInstDecl DocName)
+renameClsInstD (ClsInstDecl { cid_poly_ty =ltype, cid_tyfam_insts = lATs, cid_datafam_insts = lADTs }) = do
   ltype' <- renameLType ltype
-  lATs' <- mapM (mapM renameFamInstD) lATs
-  return (ClsInstD { cid_poly_ty = ltype', cid_binds = emptyBag, cid_sigs = []
-                   , cid_fam_insts = lATs' })
+  lATs'  <- mapM (mapM renameTyFamInstD) lATs
+  lADTs' <- mapM (mapM renameDataFamInstD) lADTs
+  return (ClsInstDecl { cid_poly_ty = ltype', cid_binds = emptyBag, cid_sigs = []
+                      , cid_tyfam_insts = lATs', cid_datafam_insts = lADTs' })
 
-renameInstD (FamInstD { lid_inst = d }) = do
-  d' <- renameFamInstD d
-  return (FamInstD { lid_inst = d' })
 
-renameFamInstD :: FamInstDecl Name -> RnM (FamInstDecl DocName)
-renameFamInstD (FamInstDecl { fid_tycon = tc, fid_pats = pats_w_bndrs, fid_defn = defn })
+renameTyFamInstD :: TyFamInstDecl Name -> RnM (TyFamInstDecl DocName)
+renameTyFamInstD (TyFamInstDecl { tfid_eqns = eqns , tfid_group = eqn_group })
+  = do { eqns' <- mapM (renameLThing renameTyFamInstEqn) eqns
+       ; return (TyFamInstDecl { tfid_eqns = eqns'
+                               , tfid_group = eqn_group
+                               , tfid_fvs = placeHolderNames }) }
+
+renameTyFamInstEqn :: TyFamInstEqn Name -> RnM (TyFamInstEqn DocName)
+renameTyFamInstEqn (TyFamInstEqn { tfie_tycon = tc, tfie_pats = pats_w_bndrs, tfie_rhs = rhs })
   = do { tc' <- renameL tc
        ; pats' <- mapM renameLType (hswb_cts pats_w_bndrs)
-       ; defn' <- renameTyDefn defn 
-       ; return (FamInstDecl { fid_tycon = tc', fid_pats = pats_w_bndrs { hswb_cts = pats' }
-                             , fid_defn = defn', fid_fvs = placeHolderNames }) }
+       ; rhs' <- renameLType rhs 
+       ; return (TyFamInstEqn { tfie_tycon = tc', tfie_pats = pats_w_bndrs { hswb_cts = pats' }
+                              , tfie_rhs = rhs' }) }
 
+renameDataFamInstD :: DataFamInstDecl Name -> RnM (DataFamInstDecl DocName)
+renameDataFamInstD (DataFamInstDecl { dfid_tycon = tc, dfid_pats = pats_w_bndrs, dfid_defn = defn })
+  = do { tc' <- renameL tc
+       ; pats' <- mapM renameLType (hswb_cts pats_w_bndrs)
+       ; defn' <- renameDataDefn defn 
+       ; return (DataFamInstDecl { dfid_tycon = tc', dfid_pats = pats_w_bndrs { hswb_cts = pats' }
+                                 , dfid_defn = defn', dfid_fvs = placeHolderNames }) }
 
 renameExportItem :: ExportItem Name -> RnM (ExportItem DocName)
 renameExportItem item = case item of
diff --git a/src/Haddock/Utils.hs b/src/Haddock/Utils.hs
index 53e8bba8..20f45c95 100644
--- a/src/Haddock/Utils.hs
+++ b/src/Haddock/Utils.hs
@@ -126,22 +126,20 @@ toInstalledDescription = hmi_description . instInfo
 restrictTo :: [Name] -> LHsDecl Name -> LHsDecl Name
 restrictTo names (L loc decl) = L loc $ case decl of
   TyClD d | isDataDecl d  -> 
-    TyClD (d { tcdTyDefn = restrictTyDefn names (tcdTyDefn d) })
+    TyClD (d { tcdDataDefn = restrictDataDefn names (tcdDataDefn d) })
   TyClD d | isClassDecl d ->
     TyClD (d { tcdSigs = restrictDecls names (tcdSigs d),
                tcdATs = restrictATs names (tcdATs d) })
   _ -> decl
 
-restrictTyDefn :: [Name] -> HsTyDefn Name -> HsTyDefn Name
-restrictTyDefn _ defn@(TySynonym {})
-  = defn
-restrictTyDefn names defn@(TyData { td_ND = new_or_data, td_cons = cons })
+restrictDataDefn :: [Name] -> HsDataDefn Name -> HsDataDefn Name
+restrictDataDefn names defn@(HsDataDefn { dd_ND = new_or_data, dd_cons = cons })
   | DataType <- new_or_data
-  = defn { td_cons = restrictCons names cons }
+  = defn { dd_cons = restrictCons names cons }
   | otherwise    -- Newtype
   = case restrictCons names cons of
-      []    -> defn { td_ND = DataType, td_cons = [] }
-      [con] -> defn { td_cons = [con] }
+      []    -> defn { dd_ND = DataType, dd_cons = [] }
+      [con] -> defn { dd_cons = [con] }
       _ -> error "Should not happen"
 
 restrictCons :: [Name] -> [LConDecl Name] -> [LConDecl Name]
@@ -169,8 +167,8 @@ restrictDecls :: [Name] -> [LSig Name] -> [LSig Name]
 restrictDecls names = mapMaybe (filterLSigNames (`elem` names))
 
 
-restrictATs :: [Name] -> [LTyClDecl Name] -> [LTyClDecl Name]
-restrictATs names ats = [ at | at <- ats , tcdName (unL at) `elem` names ]
+restrictATs :: [Name] -> [LFamilyDecl Name] -> [LFamilyDecl Name]
+restrictATs names ats = [ at | at <- ats , unL (fdLName (unL at)) `elem` names ]
 
 emptyHsQTvs :: LHsTyVarBndrs Name
 -- This function is here, rather than in HsTypes, because it *renamed*, but