newtype-wrap Doc nodes for things that may have warnings attached

8 files changed, 89 insertions, 85 deletions

diff --git a/src/Haddock/Backends/Hoogle.hs b/src/Haddock/Backends/Hoogle.hs
index e7a78fc2..98eeaab8 100644
--- a/src/Haddock/Backends/Hoogle.hs
+++ b/src/Haddock/Backends/Hoogle.hs
@@ -48,7 +48,7 @@ ppHoogle package version synopsis prologue ifaces odir = do
     hClose h
 
 ppModule :: Interface -> [String]
-ppModule iface = "" : doc (ifaceDoc iface) ++
+ppModule iface = "" : ppDocumentation (ifaceDoc iface) ++
                  ["module " ++ moduleString (ifaceMod iface)] ++
                  concatMap ppExport (ifaceExportItems iface) ++
                  concatMap ppInstance (ifaceInstances iface)
@@ -109,7 +109,7 @@ operator x = x
 -- How to print each export
 
 ppExport :: ExportItem Name -> [String]
-ppExport (ExportDecl decl dc subdocs _) = doc (fst dc) ++ f (unL decl)
+ppExport (ExportDecl decl dc subdocs _) = ppDocumentation (fst dc) ++ f (unL decl)
     where
         f (TyClD d@TyData{}) = ppData d subdocs
         f (TyClD d@ClassDecl{}) = ppClass d
@@ -167,19 +167,19 @@ ppData x subdocs = showData x{tcdCons=[],tcdDerivs=Nothing} :
                 f w = if w == nam then operator nam else w
 
 -- | for constructors, and named-fields...
-lookupCon :: [(Name, DocForDecl Name)] -> Located Name -> Maybe (Doc Name)
+lookupCon :: [(Name, DocForDecl Name)] -> Located Name -> [String]
 lookupCon subdocs (L _ name) = case lookup name subdocs of
-  Just (d, _) -> d
-  _ -> Nothing
+  Just (d, _) -> ppDocumentation d
+  _ -> []
 
 ppCtor :: TyClDecl Name -> [(Name, DocForDecl Name)] -> ConDecl Name -> [String]
-ppCtor dat subdocs con = doc (lookupCon subdocs (con_name con))
+ppCtor dat subdocs con = lookupCon subdocs (con_name con)
                          ++ f (con_details con)
     where
         f (PrefixCon args) = [typeSig name $ args ++ [resType]]
         f (InfixCon a1 a2) = f $ PrefixCon [a1,a2]
         f (RecCon recs) = f (PrefixCon $ map cd_fld_type recs) ++ concat
-                          [doc (lookupCon subdocs (cd_fld_name r)) ++
+                          [lookupCon subdocs (cd_fld_name r) ++
                            [out (unL $ cd_fld_name r) `typeSig` [resType, cd_fld_type r]]
                           | r <- recs]
 
@@ -197,6 +197,10 @@ ppCtor dat subdocs con = doc (lookupCon subdocs (con_name con))
 ---------------------------------------------------------------------
 -- DOCUMENTATION
 
+ppDocumentation :: Outputable o => Documentation o -> [String]
+ppDocumentation (Documentation d) = doc d
+
+
 doc :: Outputable o => Maybe (Doc o) -> [String]
 doc = docWith ""
 
diff --git a/src/Haddock/Backends/LaTeX.hs b/src/Haddock/Backends/LaTeX.hs
index efe05b9e..6cce753c 100644
--- a/src/Haddock/Backends/LaTeX.hs
+++ b/src/Haddock/Backends/LaTeX.hs
@@ -158,9 +158,7 @@ ppLaTeXModule _title odir iface = do
        ]
 
       description
-          = case ifaceRnDoc iface of
-              Nothing -> empty
-              Just doc -> docToLaTeX doc
+          = (fromMaybe empty . documentationToLaTeX . ifaceRnDoc) iface
 
       body = processExports exports
   --
@@ -210,7 +208,7 @@ processExports (e : es) =
 
 isSimpleSig :: ExportItem DocName -> Maybe ([DocName], HsType DocName)
 isSimpleSig (ExportDecl (L _ (SigD (TypeSig lnames (L _ t))))
-                        (Nothing, argDocs) _ _)
+                        (Documentation Nothing, argDocs) _ _)
   | Map.null argDocs = Just (map unLoc lnames, t)
 isSimpleSig _ = Nothing
 
@@ -276,24 +274,24 @@ ppDecl :: LHsDecl DocName
        -> [(DocName, DocForDecl DocName)]
        -> LaTeX
 
-ppDecl (L loc decl) (mbDoc, fnArgsDoc) instances subdocs = case decl of
-  TyClD d@(TyFamily {})          -> ppTyFam False loc mbDoc d unicode
+ppDecl (L loc decl) (doc, fnArgsDoc) instances subdocs = case decl of
+  TyClD d@(TyFamily {})          -> ppTyFam False loc doc d unicode
   TyClD d@(TyData {})
-    | Nothing <- tcdTyPats d     -> ppDataDecl instances subdocs loc mbDoc d unicode
-    | Just _  <- tcdTyPats d     -> ppDataInst loc mbDoc d
+    | Nothing <- tcdTyPats d     -> ppDataDecl instances subdocs loc doc d unicode
+    | Just _  <- tcdTyPats d     -> ppDataInst loc doc d
   TyClD d@(TySynonym {})
-    | Nothing <- tcdTyPats d     -> ppTySyn loc (mbDoc, fnArgsDoc) d unicode
-    | Just _  <- tcdTyPats d     -> ppTyInst False loc mbDoc d unicode
-  TyClD d@(ClassDecl {})         -> ppClassDecl instances loc mbDoc subdocs d unicode
-  SigD (TypeSig lnames (L _ t))  -> ppFunSig loc (mbDoc, fnArgsDoc) (map unLoc lnames) t unicode
-  ForD d                         -> ppFor loc (mbDoc, fnArgsDoc) d unicode
+    | Nothing <- tcdTyPats d     -> ppTySyn loc (doc, fnArgsDoc) d unicode
+    | Just _  <- tcdTyPats d     -> ppTyInst False loc doc d unicode
+  TyClD d@(ClassDecl {})         -> ppClassDecl instances loc doc subdocs d unicode
+  SigD (TypeSig lnames (L _ t))  -> ppFunSig loc (doc, fnArgsDoc) (map unLoc lnames) t unicode
+  ForD d                         -> ppFor loc (doc, fnArgsDoc) d unicode
   InstD _                        -> empty
   _                              -> error "declaration not supported by ppDecl"
   where
     unicode = False
 
 
-ppTyFam :: Bool -> SrcSpan -> Maybe (Doc DocName) ->
+ppTyFam :: Bool -> SrcSpan -> Documentation DocName ->
               TyClDecl DocName -> Bool -> LaTeX
 ppTyFam _ _ _ _ _ =
   error "type family declarations are currently not supported by --latex"
@@ -304,7 +302,7 @@ ppDataInst =
   error "data instance declarations are currently not supported by --latex"
 
 
-ppTyInst :: Bool -> SrcSpan -> Maybe (Doc DocName) ->
+ppTyInst :: Bool -> SrcSpan -> Documentation DocName ->
             TyClDecl DocName -> Bool -> LaTeX
 ppTyInst _ _ _ _ _ =
   error "type instance declarations are currently not supported by --latex"
@@ -355,13 +353,13 @@ ppTypeOrFunSig :: SrcSpan -> [DocName] -> HsType DocName
 ppTypeOrFunSig _ _ typ (doc, argDocs) (pref1, pref2, sep0)
                unicode
   | Map.null argDocs =
-      declWithDoc pref1 (fmap docToLaTeX doc)
+      declWithDoc pref1 (documentationToLaTeX doc)
   | otherwise        =
       declWithDoc pref2 $ Just $
         text "\\haddockbeginargs" $$
         do_args 0 sep0 typ $$
         text "\\end{tabulary}\\par" $$
-        maybe empty docToLaTeX doc
+        fromMaybe empty (documentationToLaTeX doc)
   where
      do_largs n leader (L _ t) = do_args n leader t
 
@@ -469,9 +467,9 @@ ppFds fds unicode =
 
 
 ppClassDecl :: [DocInstance DocName] -> SrcSpan
-            -> Maybe (Doc DocName) -> [(DocName, DocForDecl DocName)]
+            -> Documentation DocName -> [(DocName, DocForDecl DocName)]
             -> TyClDecl DocName -> Bool -> LaTeX
-ppClassDecl instances loc mbDoc subdocs
+ppClassDecl instances loc doc subdocs
   (ClassDecl lctxt lname ltyvars lfds lsigs _ ats at_defs _) unicode
   = declWithDoc classheader (if null body then Nothing else Just (vcat body)) $$
     instancesBit
@@ -482,7 +480,7 @@ ppClassDecl instances loc mbDoc subdocs
 
     hdr = ppClassHdr False lctxt (unLoc lname) ltyvars lfds
 
-    body = catMaybes [fmap docToLaTeX mbDoc, body_]
+    body = catMaybes [documentationToLaTeX doc, body_]
 
     body_
       | null lsigs, null ats, null at_defs = Nothing
@@ -523,8 +521,8 @@ isUndocdInstance _ = Nothing
 -- an 'argBox'. The comment is printed to the right of the box in normal comment
 -- style.
 ppDocInstance :: Bool -> DocInstance DocName -> LaTeX
-ppDocInstance unicode (instHead, mbDoc) =
-  declWithDoc (ppInstDecl unicode instHead) (fmap docToLaTeX mbDoc)
+ppDocInstance unicode (instHead, doc) =
+  declWithDoc (ppInstDecl unicode instHead) (fmap docToLaTeX doc)
 
 
 ppInstDecl :: Bool -> InstHead DocName -> LaTeX
@@ -550,9 +548,9 @@ lookupAnySubdoc n subdocs = case lookup n subdocs of
 
 ppDataDecl :: [DocInstance DocName] ->
               [(DocName, DocForDecl DocName)] ->
-              SrcSpan -> Maybe (Doc DocName) -> TyClDecl DocName -> Bool ->
+              SrcSpan -> Documentation DocName -> TyClDecl DocName -> Bool ->
               LaTeX
-ppDataDecl instances subdocs _loc mbDoc dataDecl unicode
+ppDataDecl instances subdocs _loc doc dataDecl unicode
 
    =  declWithDoc (ppDataHeader dataDecl unicode <+> whereBit)
                   (if null body then Nothing else Just (vcat body))
@@ -562,7 +560,7 @@ ppDataDecl instances subdocs _loc mbDoc dataDecl unicode
     cons      = tcdCons dataDecl
     resTy     = (con_res . unLoc . head) cons
 
-    body = catMaybes [constrBit, fmap docToLaTeX mbDoc]
+    body = catMaybes [constrBit, documentationToLaTeX doc]
 
     (whereBit, leaders)
       | null cons = (empty,[])
@@ -642,7 +640,7 @@ ppSideBySideConstr subdocs unicode leader (L _ con) =
     forall  = con_explicit con
     -- don't use "con_doc con", in case it's reconstructed from a .hi file,
     -- or also because we want Haddock to do the doc-parsing, not GHC.
-    mbDoc = lookup (unLoc $ con_name con) subdocs >>= fst
+    mbDoc = lookup (unLoc $ con_name con) subdocs >>= (\(Documentation mDoc) -> mDoc) . fst
     mkFunTy a b = noLoc (HsFunTy a b)
 
 
@@ -652,7 +650,7 @@ ppSideBySideField subdocs unicode (ConDeclField (L _ name) ltype _) =
     <+> dcolon unicode <+> ppLType unicode ltype) <-> rDoc mbDoc
   where
     -- don't use cd_fld_doc for same reason we don't use con_doc above
-    mbDoc = lookup name subdocs >>= fst
+    mbDoc = lookup name subdocs >>= (\(Documentation mDoc) -> mDoc) . fst
 
 -- {-
 -- ppHsFullConstr :: HsConDecl -> LaTeX
@@ -1042,6 +1040,10 @@ docToLaTeX :: Doc DocName -> LaTeX
 docToLaTeX doc = markup latexMarkup doc Plain
 
 
+documentationToLaTeX :: Documentation DocName -> Maybe LaTeX
+documentationToLaTeX (Documentation mDoc) = docToLaTeX `fmap` mDoc
+
+
 rdrDocToLaTeX :: Doc RdrName -> LaTeX
 rdrDocToLaTeX doc = markup rdrLatexMarkup doc Plain
 
diff --git a/src/Haddock/Backends/Xhtml.hs b/src/Haddock/Backends/Xhtml.hs
index 94ca6d10..c5925cda 100644
--- a/src/Haddock/Backends/Xhtml.hs
+++ b/src/Haddock/Backends/Xhtml.hs
@@ -508,18 +508,16 @@ ifaceToHtml maybe_source_url maybe_wiki_url iface unicode qual
 
     -- todo: if something has only sub-docs, or fn-args-docs, should
     -- it be measured here and thus prevent omitting the synopsis?
-    has_doc (ExportDecl _ doc _ _) = isJust (fst doc)
+    has_doc (ExportDecl _ (Documentation mDoc, _) _ _) = isJust mDoc
     has_doc (ExportNoDecl _ _) = False
     has_doc (ExportModule _) = False
     has_doc _ = True
 
     no_doc_at_all = not (any has_doc exports)
 
-    description
-          = case ifaceRnDoc iface of
-              Nothing -> noHtml
-              Just doc -> divDescription $
-                            sectionName << "Description" +++ docSection qual doc
+    description | isNoHtml doc = doc
+                | otherwise    = divDescription $ sectionName << "Description" +++ doc
+                where doc = docSection qual (ifaceRnDoc iface)
 
         -- omit the synopsis if there are no documentation annotations at all
     synopsis
@@ -639,7 +637,7 @@ processExport summary _ _ qual (ExportNoDecl y subs)
   = processDeclOneLiner summary $
       ppDocName qual y +++ parenList (map (ppDocName qual) subs)
 processExport summary _ _ qual (ExportDoc doc)
-  = nothingIf summary $ docSection qual doc
+  = nothingIf summary $ docSection_ qual doc
 processExport summary _ _ _ (ExportModule mdl)
   = processDeclOneLiner summary $ toHtml "module" <+> ppModule mdl
 
diff --git a/src/Haddock/Backends/Xhtml/Decl.hs b/src/Haddock/Backends/Xhtml/Decl.hs
index 3cfba1de..66b78cbd 100644
--- a/src/Haddock/Backends/Xhtml/Decl.hs
+++ b/src/Haddock/Backends/Xhtml/Decl.hs
@@ -71,9 +71,9 @@ ppTypeOrFunSig :: Bool -> LinksInfo -> SrcSpan -> [DocName] -> HsType DocName
                -> DocForDecl DocName -> (Html, Html, Html) -> Bool -> Qualification -> Html
 ppTypeOrFunSig summary links loc docnames typ (doc, argDocs) (pref1, pref2, sep) unicode qual
   | summary = pref1
-  | Map.null argDocs = topDeclElem links loc docnames pref1 +++ maybeDocSection qual doc
+  | Map.null argDocs = topDeclElem links loc docnames pref1 +++ docSection qual doc
   | otherwise = topDeclElem links loc docnames pref2 +++
-      subArguments qual (do_args 0 sep typ) +++ maybeDocSection qual doc
+      subArguments qual (do_args 0 sep typ) +++ docSection qual doc
   where
     argDoc n = Map.lookup n argDocs
 
@@ -166,12 +166,12 @@ ppTyFamHeader summary associated decl unicode qual =
     Nothing -> noHtml
 
 
-ppTyFam :: Bool -> Bool -> LinksInfo -> SrcSpan -> Maybe (Doc DocName) ->
+ppTyFam :: Bool -> Bool -> LinksInfo -> SrcSpan -> Documentation DocName ->
               TyClDecl DocName -> Bool -> Qualification -> Html
-ppTyFam summary associated links loc mbDoc decl unicode qual
+ppTyFam summary associated links loc doc decl unicode qual
 
   | summary   = ppTyFamHeader True associated decl unicode qual
-  | otherwise = header_ +++ maybeDocSection qual mbDoc +++ instancesBit
+  | otherwise = header_ +++ docSection qual doc +++ instancesBit
 
   where
     docname = tcdName decl
@@ -206,12 +206,12 @@ ppDataInst = undefined
 --------------------------------------------------------------------------------
 
 
-ppTyInst :: Bool -> Bool -> LinksInfo -> SrcSpan -> Maybe (Doc DocName) ->
+ppTyInst :: Bool -> Bool -> LinksInfo -> SrcSpan -> Documentation DocName ->
             TyClDecl DocName -> Bool -> Qualification -> Html
-ppTyInst summary associated links loc mbDoc decl unicode qual
+ppTyInst summary associated links loc doc decl unicode qual
 
   | summary   = ppTyInstHeader True associated decl unicode qual
-  | otherwise = header_ +++ maybeDocSection qual mbDoc
+  | otherwise = header_ +++ docSection qual doc
 
   where
     docname = tcdName decl
@@ -367,12 +367,12 @@ ppShortClassDecl _ _ _ _ _ _ _ = error "declaration type not supported by ppShor
 
 
 ppClassDecl :: Bool -> LinksInfo -> [DocInstance DocName] -> SrcSpan
-            -> Maybe (Doc DocName) -> [(DocName, DocForDecl DocName)]
+            -> Documentation DocName -> [(DocName, DocForDecl DocName)]
             -> TyClDecl DocName -> Bool -> Qualification -> Html
-ppClassDecl summary links instances loc mbDoc subdocs
+ppClassDecl summary links instances loc d subdocs
         decl@(ClassDecl lctxt lname ltyvars lfds lsigs _ ats _ _) unicode qual
   | summary = ppShortClassDecl summary links decl loc subdocs unicode qual
-  | otherwise = classheader +++ maybeDocSection qual mbDoc
+  | otherwise = classheader +++ docSection qual d
                   +++ atBit +++ methodBit  +++ instancesBit
   where
     classheader
@@ -449,12 +449,12 @@ ppShortDataDecl summary _links _loc dataDecl unicode qual
 
 ppDataDecl :: Bool -> LinksInfo -> [DocInstance DocName] ->
               [(DocName, DocForDecl DocName)] ->
-              SrcSpan -> Maybe (Doc DocName) -> TyClDecl DocName -> Bool ->
+              SrcSpan -> Documentation DocName -> TyClDecl DocName -> Bool ->
               Qualification -> Html
-ppDataDecl summary links instances subdocs loc mbDoc dataDecl unicode qual
+ppDataDecl summary links instances subdocs loc doc dataDecl unicode qual
 
   | summary   = ppShortDataDecl summary links loc dataDecl unicode qual
-  | otherwise = header_ +++ maybeDocSection qual mbDoc +++ constrBit +++ instancesBit
+  | otherwise = header_ +++ docSection qual doc +++ constrBit +++ instancesBit
 
   where
     docname   = unLoc . tcdLName $ dataDecl
@@ -588,7 +588,7 @@ ppSideBySideConstr subdocs unicode qual (L _ con) = (decl, mbDoc, fieldPart)
     forall_ = con_explicit con
     -- don't use "con_doc con", in case it's reconstructed from a .hi file,
     -- or also because we want Haddock to do the doc-parsing, not GHC.
-    mbDoc = lookup (unLoc $ con_name con) subdocs >>= fst
+    mbDoc = lookup (unLoc $ con_name con) subdocs >>= (\(Documentation mDoc) -> mDoc) . fst
     mkFunTy a b = noLoc (HsFunTy a b)
 
 
@@ -600,7 +600,7 @@ ppSideBySideField subdocs unicode qual (ConDeclField (L _ name) ltype _) =
     [])
   where
     -- don't use cd_fld_doc for same reason we don't use con_doc above
-    mbDoc = lookup name subdocs >>= fst
+    mbDoc = lookup name subdocs >>= (\(Documentation mDoc) -> mDoc) . fst
 
 
 ppShortField :: Bool -> Bool -> Qualification -> ConDeclField DocName -> Html
diff --git a/src/Haddock/Backends/Xhtml/DocMarkup.hs b/src/Haddock/Backends/Xhtml/DocMarkup.hs
index ee0a549f..cd1595f6 100644
--- a/src/Haddock/Backends/Xhtml/DocMarkup.hs
+++ b/src/Haddock/Backends/Xhtml/DocMarkup.hs
@@ -15,7 +15,7 @@ module Haddock.Backends.Xhtml.DocMarkup (
   rdrDocToHtml,
   origDocToHtml,
 
-  docElement, docSection, maybeDocSection,
+  docElement, docSection, docSection_,
 ) where
 
 
@@ -85,12 +85,12 @@ docElement el content_ =
     else el ! [theclass "doc"] << content_
 
 
-docSection :: Qualification -> Doc DocName -> Html
-docSection qual = (docElement thediv <<) . docToHtml qual
+docSection :: Qualification -> Documentation DocName -> Html
+docSection qual (Documentation doc) = maybe noHtml (docSection_ qual) doc
 
 
-maybeDocSection :: Qualification -> Maybe (Doc DocName) -> Html
-maybeDocSection qual = maybe noHtml (docSection qual)
+docSection_ :: Qualification -> Doc DocName -> Html
+docSection_ qual = (docElement thediv <<) . docToHtml qual
 
 
 cleanup :: Doc a -> Doc a
diff --git a/src/Haddock/Interface/Create.hs b/src/Haddock/Interface/Create.hs
index ea4636fe..e2cc9959 100644
--- a/src/Haddock/Interface/Create.hs
+++ b/src/Haddock/Interface/Create.hs
@@ -117,8 +117,8 @@ createInterface tm flags modMap instIfaceMap = do
     ifaceMod             = mdl,
     ifaceOrigFilename    = msHsFilePath ms,
     ifaceInfo            = info,
-    ifaceDoc             = mbDoc,
-    ifaceRnDoc           = Nothing,
+    ifaceDoc             = Documentation mbDoc,
+    ifaceRnDoc           = Documentation Nothing,
     ifaceOptions         = opts,
     ifaceDocMap          = docMap,
     ifaceArgMap          = argMap,
@@ -609,10 +609,12 @@ hiValExportItem name doc = do
 lookupDocs :: Name -> DocMap Name -> ArgMap Name -> SubMap -> (DocForDecl Name, [(Name, DocForDecl Name)])
 lookupDocs n docMap argMap subMap =
   let lookupArgDoc x = M.findWithDefault M.empty x argMap in
-  let doc = (M.lookup n docMap, lookupArgDoc n) in
+  let doc = (lookupDoc n, lookupArgDoc n) in
   let subs = M.findWithDefault [] n subMap in
-  let subDocs = [ (s, (M.lookup s docMap, lookupArgDoc s)) | s <- subs ] in
+  let subDocs = [ (s, (lookupDoc s, lookupArgDoc s)) | s <- subs ] in
   (doc, subDocs)
+  where
+    lookupDoc = Documentation . (`M.lookup` docMap)
 
 
 -- | Return all export items produced by an exported module. That is, we're
@@ -772,7 +774,7 @@ extractRecSel nm mdl t tvs (L _ con : rest) =
 pruneExportItems :: [ExportItem Name] -> [ExportItem Name]
 pruneExportItems = filter hasDoc
   where
-    hasDoc (ExportDecl{expItemMbDoc = (d, _)}) = isJust d
+    hasDoc (ExportDecl{expItemMbDoc = (Documentation d, _)}) = isJust d
     hasDoc _ = True
 
 
diff --git a/src/Haddock/Interface/Rename.hs b/src/Haddock/Interface/Rename.hs
index cffe68b8..fd2a1f10 100644
--- a/src/Haddock/Interface/Rename.hs
+++ b/src/Haddock/Interface/Rename.hs
@@ -47,7 +47,7 @@ renameInterface renamingEnv warnings iface =
       (rnArgMap, missingNames3) = runRnFM localEnv (mapM (mapM renameDoc) (ifaceArgMap iface))
 
       (finalModuleDoc, missingNames4)
-        = runRnFM localEnv (renameMaybeDoc (ifaceDoc iface))
+        = runRnFM localEnv (renameDocumentation (ifaceDoc iface))
 
       -- combine the missing names and filter out the built-ins, which would
       -- otherwise allways be missing.
@@ -142,15 +142,13 @@ renameExportItems :: [ExportItem Name] -> RnM [ExportItem DocName]
 renameExportItems = mapM renameExportItem
 
 
-renameDocForDecl :: (Maybe (Doc Name), FnArgsDoc Name) -> RnM (Maybe (Doc DocName), FnArgsDoc DocName)
-renameDocForDecl (mbDoc, fnArgsDoc) = do
-  mbDoc' <- renameMaybeDoc mbDoc
-  fnArgsDoc' <- renameFnArgsDoc fnArgsDoc
-  return (mbDoc', fnArgsDoc')
+renameDocForDecl :: DocForDecl Name -> RnM (DocForDecl DocName)
+renameDocForDecl (doc, fnArgsDoc) =
+  (,) `fmap` renameDocumentation doc `ap` renameFnArgsDoc fnArgsDoc
 
 
-renameMaybeDoc :: Maybe (Doc Name) -> RnM (Maybe (Doc DocName))
-renameMaybeDoc = mapM renameDoc
+renameDocumentation :: Documentation Name -> RnM (Documentation DocName)
+renameDocumentation (Documentation mDoc) = Documentation <$> mapM renameDoc mDoc
 
 
 renameLDocHsSyn :: LHsDocString -> RnM LHsDocString
diff --git a/src/Haddock/Types.hs b/src/Haddock/Types.hs
index 97d56a52..f8d51b2b 100644
--- a/src/Haddock/Types.hs
+++ b/src/Haddock/Types.hs
@@ -67,10 +67,10 @@ data Interface = Interface
   , ifaceInfo            :: !(HaddockModInfo Name)
 
     -- | Documentation header.
-  , ifaceDoc             :: !(Maybe (Doc Name))
+  , ifaceDoc             :: !(Documentation Name)
 
     -- | Documentation header with cross-reference information.
-  , ifaceRnDoc           :: Maybe (Doc DocName)
+  , ifaceRnDoc           :: Documentation DocName
 
     -- | Haddock options for this module (prune, ignore-exports, etc).
   , ifaceOptions         :: ![DocOption]
@@ -214,19 +214,23 @@ data ExportItem name
   | ExportModule Module
 
 
+newtype Documentation name = Documentation (Maybe (Doc name))
+  deriving Functor
+
+
 -- | Arguments and result are indexed by Int, zero-based from the left,
 -- because that's the easiest to use when recursing over types.
 type FnArgsDoc name = Map Int (Doc name)
-type DocForDecl name = (Maybe (Doc name), FnArgsDoc name)
+type DocForDecl name = (Documentation name, FnArgsDoc name)
 
 
 noDocForDecl :: DocForDecl name
-noDocForDecl = (Nothing, Map.empty)
+noDocForDecl = (Documentation Nothing, Map.empty)
 
 
 unrenameDocForDecl :: DocForDecl DocName -> DocForDecl Name
-unrenameDocForDecl (mbDoc, fnArgsDoc) =
-    (fmap unrenameDoc mbDoc, fmap unrenameDoc fnArgsDoc)
+unrenameDocForDecl (doc, fnArgsDoc) =
+    (fmap getName doc, (fmap . fmap) getName fnArgsDoc)
 
 
 -----------------------------------------------------------------------------
@@ -304,10 +308,6 @@ instance Monoid (Doc id) where
   mappend = DocAppend
 
 
-unrenameDoc :: Doc DocName -> Doc Name
-unrenameDoc = fmap getName
-
-
 data Example = Example
   { exampleExpression :: String
   , exampleResult     :: [String]