* Merge in git patch from Michal Terepeta

From 6fc71d067738ef4b7de159327bb6dc3d0596be29 Mon Sep 17 00:00:00 2001
From: Michal Terepeta <michal.terepeta@gmail.com>
Date: Sat, 14 May 2011 19:18:22 +0200
Subject: [PATCH] Follow the change of TypeSig in GHC.

This follows the change in GHC to make TypeSig take a list
of names (instead of just one); GHC ticket #1595. This
should also improve the Haddock output in case the user
writes a type signature that refers to many names:
  -- | Some comment..
  foo, bar :: ...
will now generate the expected output with one signature for
both names.

5 files changed, 103 insertions, 82 deletions

diff --git a/src/Haddock/Backends/Hoogle.hs b/src/Haddock/Backends/Hoogle.hs
index e4415db9..44e83d64 100644
--- a/src/Haddock/Backends/Hoogle.hs
+++ b/src/Haddock/Backends/Hoogle.hs
@@ -114,16 +114,17 @@ ppExport (ExportDecl decl dc subdocs _) = doc (fst dc) ++ f (unL decl)
         f (TyClD d@TyData{}) = ppData d subdocs
         f (TyClD d@ClassDecl{}) = ppClass d
         f (TyClD d@TySynonym{}) = ppSynonym d
-        f (ForD (ForeignImport name typ _)) = ppSig $ TypeSig name typ
-        f (ForD (ForeignExport name typ _)) = ppSig $ TypeSig name typ
+        f (ForD (ForeignImport name typ _)) = ppSig $ TypeSig [name] typ
+        f (ForD (ForeignExport name typ _)) = ppSig $ TypeSig [name] typ
         f (SigD sig) = ppSig sig
         f _ = []
 ppExport _ = []
 
 
 ppSig :: Sig Name -> [String]
-ppSig (TypeSig name sig) = [operator (out name) ++ " :: " ++ outHsType typ]
+ppSig (TypeSig names sig) = [operator prettyNames ++ " :: " ++ outHsType typ]
     where
+        prettyNames = concat . intersperse ", " $ map out names
         typ = case unL sig of
                    HsForAllTy Explicit a b c -> HsForAllTy Implicit a b c
                    x -> x
diff --git a/src/Haddock/Backends/LaTeX.hs b/src/Haddock/Backends/LaTeX.hs
index 71773d0d..27f6bd5e 100644
--- a/src/Haddock/Backends/LaTeX.hs
+++ b/src/Haddock/Backends/LaTeX.hs
@@ -177,7 +177,7 @@ string_txt (LStr s1 _) s2 = unpackLitString s1 ++ s2
 
 exportListItem :: ExportItem DocName -> LaTeX
 exportListItem (ExportDecl decl _doc subdocs _insts)
-  = ppDocBinder (declName decl) <>
+  = sep (punctuate comma . map ppDocBinder $ declNames decl) <>
      case subdocs of
        [] -> empty
        _  -> parens (sep (punctuate comma (map (ppDocBinder . fst) subdocs)))
@@ -197,8 +197,8 @@ processExports :: [ExportItem DocName] -> LaTeX
 processExports [] = empty
 processExports (decl : es)
   | Just sig <- isSimpleSig decl
-  = multiDecl [ ppTypeSig (getName name) typ False
-              | (name,typ) <- sig:sigs ] $$
+  = multiDecl [ ppTypeSig (map getName names) typ False
+              | (names,typ) <- sig:sigs ] $$
     processExports es'
   where (sigs, es') = spanWith isSimpleSig es
 processExports (ExportModule mdl : es)
@@ -209,10 +209,10 @@ processExports (e : es) =
   processExport e $$ processExports es
 
 
-isSimpleSig :: ExportItem DocName -> Maybe (DocName, HsType DocName)
-isSimpleSig (ExportDecl (L _ (SigD (TypeSig (L _ n) (L _ t))))
+isSimpleSig :: ExportItem DocName -> Maybe ([DocName], HsType DocName)
+isSimpleSig (ExportDecl (L _ (SigD (TypeSig lnames (L _ t))))
                         (Nothing, argDocs) _ _)
-  | Map.null argDocs = Just (n, t)
+  | Map.null argDocs = Just (map unLoc lnames, t)
 isSimpleSig _ = Nothing
 
 
@@ -244,11 +244,11 @@ ppDocGroup lev doc = sec lev <> braces doc
         sec _ = text "\\paragraph"
 
 
-declName :: LHsDecl DocName -> DocName
-declName (L _ decl) = case decl of
-  TyClD d  -> unLoc $ tcdLName d
-  SigD (TypeSig (L _ n) _) -> n
-  _ -> error "declaration not supported by declName"
+declNames :: LHsDecl DocName -> [DocName]
+declNames (L _ decl) = case decl of
+  TyClD d  -> [unLoc $ tcdLName d]
+  SigD (TypeSig lnames _) -> map unLoc lnames
+  _ -> error "declaration not supported by declNames"
 
 
 forSummary :: (ExportItem DocName) -> Bool
@@ -286,7 +286,7 @@ ppDecl (L loc decl) (mbDoc, fnArgsDoc) instances subdocs = case decl of
     | 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 (L _ n) (L _ t)) -> ppFunSig loc (mbDoc, fnArgsDoc) n t unicode
+  SigD (TypeSig lnames (L _ t))  -> ppFunSig loc (mbDoc, fnArgsDoc) (map unLoc lnames) t unicode
   ForD d                         -> ppFor loc (mbDoc, fnArgsDoc) d unicode
   InstD _                        -> empty
   _                              -> error "declaration not supported by ppDecl"
@@ -325,7 +325,7 @@ ppFor _ _ _ _ =
 ppTySyn :: SrcSpan -> DocForDecl DocName -> TyClDecl DocName -> Bool -> LaTeX
 
 ppTySyn loc doc (TySynonym (L _ name) ltyvars _ ltype) unicode
-  = ppTypeOrFunSig loc name (unLoc ltype) doc (full, hdr, char '=') unicode
+  = ppTypeOrFunSig loc [name] (unLoc ltype) doc (full, hdr, char '=') unicode
   where
     hdr  = hsep (keyword "type" : ppDocBinder name : ppTyVars ltyvars)
     full = hdr <+> char '=' <+> ppLType unicode ltype
@@ -338,20 +338,22 @@ ppTySyn _ _ _ _ = error "declaration not supported by ppTySyn"
 -------------------------------------------------------------------------------
 
 
-ppFunSig :: SrcSpan -> DocForDecl DocName -> DocName -> HsType DocName
+ppFunSig :: SrcSpan -> DocForDecl DocName -> [DocName] -> HsType DocName
          -> Bool -> LaTeX
-ppFunSig loc doc docname typ unicode =
-  ppTypeOrFunSig loc docname typ doc
-    (ppTypeSig name typ False, ppSymName name, dcolon unicode)
+ppFunSig loc doc docnames typ unicode =
+  ppTypeOrFunSig loc docnames typ doc
+    ( ppTypeSig names typ False
+    , hsep . punctuate comma $ map ppSymName names
+    , dcolon unicode)
     unicode
  where
-   name = getName docname
+   names = map getName docnames
 
 
-ppTypeOrFunSig :: SrcSpan -> DocName -> HsType DocName ->
-                  DocForDecl DocName -> (LaTeX, LaTeX, LaTeX)
+ppTypeOrFunSig :: SrcSpan -> [DocName] -> HsType DocName
+               -> DocForDecl DocName -> (LaTeX, LaTeX, LaTeX)
                -> Bool -> LaTeX
-ppTypeOrFunSig _loc _docname typ (doc, argDocs) (pref1, pref2, sep0)
+ppTypeOrFunSig _ _ typ (doc, argDocs) (pref1, pref2, sep0)
                unicode
   | Map.null argDocs =
       declWithDoc pref1 (fmap docToLaTeX doc)
@@ -388,9 +390,11 @@ ppTypeOrFunSig _loc _docname typ (doc, argDocs) (pref1, pref2, sep0)
        = decltt leader <-> decltt (ppType unicode t) <-> arg_doc n <+> nl
 
 
-ppTypeSig :: Name -> HsType DocName  -> Bool -> LaTeX
-ppTypeSig nm ty unicode =
-  ppSymName nm <+> dcolon unicode <+> ppType unicode ty
+ppTypeSig :: [Name] -> HsType DocName  -> Bool -> LaTeX
+ppTypeSig nms ty unicode =
+  hsep (punctuate comma $ map ppSymName nms)
+    <+> dcolon unicode
+    <+> ppType unicode ty
 
 
 ppTyVars :: [LHsTyVarBndr DocName] -> [LaTeX]
@@ -489,12 +493,13 @@ ppClassDecl instances loc mbDoc subdocs
 
     methodTable =
       text "\\haddockpremethods{}\\textbf{Methods}" $$
-      vcat  [ ppFunSig loc doc n typ unicode
-            | L _ (TypeSig (L _ n) (L _ typ)) <- lsigs
-            , let doc = lookupAnySubdoc n subdocs ]
-
---    atTable = abovesSep s8 $ [ ppAssocType summary links doc at unicode | at <- ats
---                             , let doc = lookupAnySubdoc (tcdName $ unL at) subdocs ]
+      vcat  [ ppFunSig loc doc names typ unicode
+            | L _ (TypeSig lnames (L _ typ)) <- lsigs
+            , let doc = lookupAnySubdoc (head names) subdocs
+                  names = map unLoc lnames ]
+              -- FIXME: is taking just the first name ok? Is it possible that
+              -- there are different subdocs for different names in a single
+              -- type signature?
 
     instancesBit = ppDocInstances unicode instances
 
diff --git a/src/Haddock/Backends/Xhtml.hs b/src/Haddock/Backends/Xhtml.hs
index 3bc2dd6f..d3d3c79c 100644
--- a/src/Haddock/Backends/Xhtml.hs
+++ b/src/Haddock/Backends/Xhtml.hs
@@ -547,31 +547,31 @@ ifaceToHtml maybe_source_url maybe_wiki_url iface unicode qual
 
 miniSynopsis :: Module -> Interface -> Bool -> Qualification -> Html
 miniSynopsis mdl iface unicode qual =
-    divInterface << mapMaybe (processForMiniSynopsis mdl unicode qual) exports
+    divInterface << concatMap (processForMiniSynopsis mdl unicode qual) exports
   where
     exports = numberSectionHeadings (ifaceRnExportItems iface)
 
 
 processForMiniSynopsis :: Module -> Bool -> Qualification -> ExportItem DocName
-                       -> Maybe Html
+                       -> [Html]
 processForMiniSynopsis mdl unicode _ (ExportDecl (L _loc decl0) _doc _ _insts) =
   ((divTopDecl <<).(declElem <<)) `fmap` case decl0 of
     TyClD d -> let b = ppTyClBinderWithVarsMini mdl d in case d of
-        (TyFamily{}) -> Just $ ppTyFamHeader True False d unicode
+        (TyFamily{}) -> [ppTyFamHeader True False d unicode]
         (TyData{tcdTyPats = ps})
-          | Nothing <- ps -> Just $ keyword "data" <+> b
-          | Just _ <- ps  -> Just $ keyword "data" <+> keyword "instance" <+> b
+          | Nothing <- ps -> [keyword "data" <+> b]
+          | Just _ <- ps  -> [keyword "data" <+> keyword "instance" <+> b]
         (TySynonym{tcdTyPats = ps})
-          | Nothing <- ps -> Just $ keyword "type" <+> b
-          | Just _ <- ps  -> Just $ keyword "type" <+> keyword "instance" <+> b
-        (ClassDecl {})    -> Just $ keyword "class" <+> b
-        _ -> Nothing
-    SigD (TypeSig (L _ n) (L _ _)) ->
-         Just $ ppNameMini mdl (nameOccName . getName $ n)
-    _ -> Nothing
+          | Nothing <- ps -> [keyword "type" <+> b]
+          | Just _ <- ps  -> [keyword "type" <+> keyword "instance" <+> b]
+        (ClassDecl {})    -> [keyword "class" <+> b]
+        _ -> []
+    SigD (TypeSig lnames (L _ _)) ->
+      map (ppNameMini mdl . nameOccName . getName . unLoc) lnames
+    _ -> []
 processForMiniSynopsis _ _ qual (ExportGroup lvl _id txt) =
-  Just $ groupTag lvl << docToHtml qual txt
-processForMiniSynopsis _ _ _ _ = Nothing
+  [groupTag lvl << docToHtml qual txt]
+processForMiniSynopsis _ _ _ = []
 
 
 ppNameMini :: Module -> OccName -> Html
diff --git a/src/Haddock/Backends/Xhtml/Decl.hs b/src/Haddock/Backends/Xhtml/Decl.hs
index 381802b4..bd93ac25 100644
--- a/src/Haddock/Backends/Xhtml/Decl.hs
+++ b/src/Haddock/Backends/Xhtml/Decl.hs
@@ -27,6 +27,7 @@ import Haddock.GhcUtils
 import Haddock.Types
 
 import           Control.Monad         ( join )
+import           Data.List             ( intersperse )
 import qualified Data.Map as Map
 import           Data.Maybe
 import           Text.XHtml hiding     ( name, title, p, quote )
@@ -50,28 +51,31 @@ ppDecl summ links (L loc decl) (mbDoc, fnArgsDoc) instances subdocs unicode qual
     | Nothing <- tcdTyPats d     -> ppTySyn summ links loc (mbDoc, fnArgsDoc) d unicode qual
     | Just _  <- tcdTyPats d     -> ppTyInst summ False links loc mbDoc d unicode qual
   TyClD d@(ClassDecl {})         -> ppClassDecl summ links instances loc mbDoc subdocs d unicode qual
-  SigD (TypeSig (L _ n) (L _ t)) -> ppFunSig summ links loc (mbDoc, fnArgsDoc) n t 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
   InstD _                        -> noHtml
   _                              -> error "declaration not supported by ppDecl"
 
 
 ppFunSig :: Bool -> LinksInfo -> SrcSpan -> DocForDecl DocName ->
-            DocName -> HsType DocName -> Bool -> Qualification -> Html
-ppFunSig summary links loc doc docname typ unicode qual =
-  ppTypeOrFunSig summary links loc docname typ doc
-    (ppTypeSig summary occname typ unicode qual, ppBinder False occname, dcolon unicode)
+            [DocName] -> HsType DocName -> Bool Qualification -> Html
+ppFunSig summary links loc doc docnames typ unicode qual =
+  ppTypeOrFunSig summary links loc docnames typ doc
+    ( ppTypeSig summary occnames typ unicode qual
+    , concatHtml . punctuate comma $ map (ppBinder False) occnames
+    , dcolon unicode
+    )
     unicode qual
   where
-    occname = nameOccName . getName $ docname
+    occnames = map (nameOccName . getName) docnames
 
 
-ppTypeOrFunSig :: Bool -> LinksInfo -> SrcSpan -> DocName -> HsType DocName ->
-                  DocForDecl DocName -> (Html, Html, Html) -> Bool -> Qualification-> Html
-ppTypeOrFunSig summary links loc docname typ (doc, argDocs) (pref1, pref2, sep) unicode qual
+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 docname pref1 +++ maybeDocSection qual doc
-  | otherwise = topDeclElem links loc docname pref2 +++
+  | Map.null argDocs = topDeclElem links loc docnames pref1 +++ maybeDocSection qual doc
+  | otherwise = topDeclElem links loc docnames pref2 +++
       subArguments qual (do_args 0 sep typ) +++ maybeDocSection qual doc
   where
     argDoc n = Map.lookup n argDocs
@@ -108,10 +112,10 @@ tyvarNames :: [LHsTyVarBndr DocName] -> [Name]
 tyvarNames = map (getName . hsTyVarName . unLoc)
 
 
-ppFor :: Bool -> LinksInfo -> SrcSpan -> DocForDecl DocName -> ForeignDecl DocName -> Bool 
-      -> Qualification -> Html
+ppFor :: Bool -> LinksInfo -> SrcSpan -> DocForDecl DocName
+      -> ForeignDecl DocName -> Bool -> Qualification -> Html
 ppFor summary links loc doc (ForeignImport (L _ name) (L _ typ) _) unicode qual
-  = ppFunSig summary links loc doc name typ unicode qual
+  = ppFunSig summary links loc doc [name] typ unicode qual
 ppFor _ _ _ _ _ _ _ = error "ppFor"
 
 
@@ -119,7 +123,7 @@ ppFor _ _ _ _ _ _ _ = error "ppFor"
 ppTySyn :: Bool -> LinksInfo -> SrcSpan -> DocForDecl DocName -> TyClDecl DocName -> Bool
         -> Qualification -> Html
 ppTySyn summary links loc doc (TySynonym (L _ name) ltyvars _ ltype) unicode qual
-  = ppTypeOrFunSig summary links loc name (unLoc ltype) doc
+  = ppTypeOrFunSig summary links loc [name] (unLoc ltype) doc
                    (full, hdr, spaceHtml +++ equals) unicode qual
   where
     hdr  = hsep ([keyword "type", ppBinder summary occ] ++ ppTyVars ltyvars)
@@ -128,9 +132,11 @@ ppTySyn summary links loc doc (TySynonym (L _ name) ltyvars _ ltype) unicode qua
 ppTySyn _ _ _ _ _ _ _ = error "declaration not supported by ppTySyn"
 
 
-ppTypeSig :: Bool -> OccName -> HsType DocName  -> Bool -> Qualification -> Html
-ppTypeSig summary nm ty unicode qual =
-    ppBinder summary nm <+> dcolon unicode <+> ppType unicode qual ty
+ppTypeSig :: Bool -> [OccName] -> HsType DocName  -> Bool -> Qualification -> Html
+ppTypeSig summary nms ty unicode qual =
+  concatHtml htmlNames <+> dcolon unicode <+> ppType unicode qual ty
+  where
+    htmlNames = intersperse (stringToHtml ", ") $ map (ppBinder summary) nms
 
 
 ppTyName :: Name -> Html
@@ -173,7 +179,7 @@ ppTyFam summary associated links loc mbDoc decl unicode qual
   where
     docname = tcdName decl
 
-    header_ = topDeclElem links loc docname (ppTyFamHeader summary associated decl unicode)
+    header_ = topDeclElem links loc [docname] (ppTyFamHeader summary associated decl unicode)
 
     instancesBit = ppInstances instances docname unicode qual
 
@@ -213,8 +219,8 @@ ppTyInst summary associated links loc mbDoc decl unicode qual
   where
     docname = tcdName decl
 
-    header_ = topDeclElem links loc docname
-        (ppTyInstHeader summary associated decl unicode qual)
+    header_ = topDeclElem links loc [docname]
+                (ppTyInstHeader summary associated decl unicode qual)
 
 
 ppTyInstHeader :: Bool -> Bool -> TyClDecl DocName -> Bool -> Qualification -> Html
@@ -349,16 +355,20 @@ ppShortClassDecl :: Bool -> LinksInfo -> TyClDecl DocName -> SrcSpan
 ppShortClassDecl summary links (ClassDecl lctxt lname tvs fds sigs _ ats _) loc
     subdocs unicode qual = 
   if null sigs && null ats
-    then (if summary then id else topDeclElem links loc nm) hdr
-    else (if summary then id else topDeclElem links loc nm) (hdr <+> keyword "where")
+    then (if summary then id else topDeclElem links loc [nm]) hdr
+    else (if summary then id else topDeclElem links loc [nm]) (hdr <+> keyword "where")
       +++ shortSubDecls
           (
             [ ppAssocType summary links doc at unicode qual | at <- ats
               , let doc = lookupAnySubdoc (tcdName $ unL at) subdocs ]  ++
 
-            [ ppFunSig summary links loc doc n typ unicode qual
-              | L _ (TypeSig (L _ n) (L _ typ)) <- sigs
-              , let doc = lookupAnySubdoc n subdocs ]
+            [ ppFunSig summary links loc doc names typ unicode qual
+              | L _ (TypeSig lnames (L _ typ)) <- sigs
+              , let doc = lookupAnySubdoc (head names) subdocs
+                    names = map unLoc lnames ]
+              -- FIXME: is taking just the first name ok? Is it possible that
+              -- there are different subdocs for different names in a single
+              -- type signature?
           )
   where
     hdr = ppClassHdr summary lctxt (unLoc lname) tvs fds unicode qual
@@ -377,8 +387,8 @@ ppClassDecl summary links instances loc mbDoc subdocs
                   +++ atBit +++ methodBit  +++ instancesBit
   where
     classheader
-      | null lsigs = topDeclElem links loc nm (hdr unicode qual)
-      | otherwise  = topDeclElem links loc nm (hdr unicode qual <+> keyword "where")
+      | null lsigs = topDeclElem links loc [nm] (hdr unicode qual)
+      | otherwise  = topDeclElem links loc [nm] (hdr unicode qual <+> keyword "where")
 
     nm   = unLoc $ tcdLName decl
 
@@ -388,9 +398,13 @@ ppClassDecl summary links instances loc mbDoc subdocs
                       | at <- ats
                       , let doc = lookupAnySubdoc (tcdName $ unL at) subdocs ]
 
-    methodBit = subMethods [ ppFunSig summary links loc doc n typ unicode qual
-                      | L _ (TypeSig (L _ n) (L _ typ)) <- lsigs
-                      , let doc = lookupAnySubdoc n subdocs ]
+    methodBit = subMethods [ ppFunSig summary links loc doc names typ unicode qual
+                           | L _ (TypeSig lnames (L _ typ)) <- lsigs
+                           , let doc = lookupAnySubdoc (head names) subdocs
+                                 names = map unLoc lnames ]
+                           -- FIXME: is taking just the first name ok? Is it possible that
+                           -- there are different subdocs for different names in a single
+                           -- type signature?
 
     instancesBit = ppInstances instances nm unicode qual 
 
@@ -461,7 +475,7 @@ ppDataDecl summary links instances subdocs loc mbDoc dataDecl unicode qual
     cons      = tcdCons dataDecl
     resTy     = (con_res . unLoc . head) cons
 
-    header_ = topDeclElem links loc docname (ppDataHeader summary dataDecl unicode qual
+    header_ = topDeclElem links loc [docname] (ppDataHeader summary dataDecl unicode qual
              <+> whereBit)
 
     whereBit
diff --git a/src/Haddock/Backends/Xhtml/Layout.hs b/src/Haddock/Backends/Xhtml/Layout.hs
index e5d8c24e..91eac9c6 100644
--- a/src/Haddock/Backends/Xhtml/Layout.hs
+++ b/src/Haddock/Backends/Xhtml/Layout.hs
@@ -176,8 +176,8 @@ declElem = paragraph ! [theclass "src"]
 
 -- a box for top level documented names
 -- it adds a source and wiki link at the right hand side of the box
-topDeclElem :: LinksInfo -> SrcSpan -> DocName -> Html -> Html
-topDeclElem ((_,_,sourceMap), (_,_,maybe_wiki_url)) loc name html =
+topDeclElem :: LinksInfo -> SrcSpan -> [DocName] -> Html -> Html
+topDeclElem ((_,_,sourceMap), (_,_,maybe_wiki_url)) loc names html =
     declElem << (html +++ srcLink +++ wikiLink)
   where srcLink =
           case Map.lookup origPkg sourceMap of
@@ -201,7 +201,8 @@ topDeclElem ((_,_,sourceMap), (_,_,maybe_wiki_url)) loc name html =
         origPkg = modulePackageId origMod
 
         -- Name must be documented, otherwise we wouldn't get here
-        Documented n mdl = name
+        Documented n mdl = head names
+        -- FIXME: is it ok to simply take the first name?
 
         fname = unpackFS (srcSpanFile loc)