----------------------------------------------------------------------------- -- | -- Module : Haddock.Interface.Create -- Copyright : (c) Simon Marlow 2003-2006, -- David Waern 2006-2009 -- License : BSD-like -- -- Maintainer : haddock@projects.haskell.org -- Stability : experimental -- Portability : portable ----------------------------------------------------------------------------- module Haddock.Interface.Create (createInterface) where import Haddock.Types import Haddock.Options import Haddock.GhcUtils import Haddock.Utils import Haddock.Convert import Haddock.Interface.LexParseRn import Haddock.Interface.ExtractFnArgDocs import qualified Data.Map as Map import Data.Map (Map) import Data.List import Data.Maybe import Data.Ord import Control.Monad import qualified Data.Traversable as Traversable import GHC hiding (flags) import Name import Bag import RdrName (GlobalRdrEnv) -- | Process the data in the GhcModule to produce an interface. -- To do this, we need access to already processed modules in the topological -- sort. That's what's in the module map. createInterface :: GhcModule -> [Flag] -> ModuleMap -> InstIfaceMap -> ErrMsgGhc Interface createInterface ghcMod flags modMap instIfaceMap = do let mdl = ghcModule ghcMod -- The pattern-match should not fail, because createInterface is only -- done on loaded modules. Just gre <- liftGhcToErrMsgGhc $ lookupLoadedHomeModuleGRE (moduleName mdl) opts0 <- liftErrMsg $ mkDocOpts (ghcMbDocOpts ghcMod) flags mdl let opts | Flag_IgnoreAllExports `elem` flags = OptIgnoreExports : opts0 | otherwise = opts0 (info, mbDoc) <- liftErrMsg $ lexParseRnHaddockModHeader gre (ghcMbDocHdr ghcMod) decls0 <- liftErrMsg $ declInfos gre (topDecls (ghcGroup ghcMod)) let decls = filterOutInstances decls0 declMap = mkDeclMap decls exports = fmap (reverse . map unLoc) (ghcMbExports ghcMod) localNames = ghcDefinedNames ghcMod ignoreExps = Flag_IgnoreAllExports `elem` flags exportedNames = ghcExportedNames ghcMod instances = ghcInstances ghcMod liftErrMsg $ warnAboutFilteredDecls mdl decls0 exportItems <- mkExportItems modMap mdl gre (ghcExportedNames ghcMod) decls declMap opts exports ignoreExps instances instIfaceMap let visibleNames = mkVisibleNames exportItems opts -- prune the export list to just those declarations that have -- documentation, if the 'prune' option is on. let prunedExportItems | OptPrune `elem` opts = pruneExportItems exportItems | otherwise = exportItems return Interface { ifaceMod = mdl, ifaceOrigFilename = ghcFilename ghcMod, ifaceInfo = info, ifaceDoc = mbDoc, ifaceRnDoc = Nothing, ifaceOptions = opts, ifaceLocals = localNames, ifaceRnDocMap = Map.empty, ifaceExportItems = prunedExportItems, ifaceRnExportItems = [], ifaceExports = exportedNames, ifaceVisibleExports = visibleNames, ifaceDeclMap = declMap, ifaceSubMap = mkSubMap declMap exportedNames, ifaceInstances = ghcInstances ghcMod } ------------------------------------------------------------------------------- -- Doc options -- -- Haddock options that are embedded in the source file ------------------------------------------------------------------------------- mkDocOpts :: Maybe String -> [Flag] -> Module -> ErrMsgM [DocOption] mkDocOpts mbOpts flags mdl = do opts <- case mbOpts of Just opts -> case words $ replace ',' ' ' opts of [] -> tell ["No option supplied to DOC_OPTION/doc_option"] >> return [] xs -> liftM catMaybes (mapM parseOption xs) Nothing -> return [] if Flag_HideModule (moduleString mdl) `elem` flags then return $ OptHide : opts else return opts parseOption :: String -> ErrMsgM (Maybe DocOption) parseOption "hide" = return (Just OptHide) parseOption "prune" = return (Just OptPrune) parseOption "ignore-exports" = return (Just OptIgnoreExports) parseOption "not-home" = return (Just OptNotHome) parseOption other = tell ["Unrecognised option: " ++ other] >> return Nothing -------------------------------------------------------------------------------- -- Declarations -------------------------------------------------------------------------------- -- | Make a sub map from a declaration map. Make sure we only include exported -- names. mkSubMap :: Map Name DeclInfo -> [Name] -> Map Name [Name] mkSubMap declMap exports = Map.filterWithKey (\k _ -> k `elem` exports) (Map.map filterSubs declMap) where filterSubs (_, _, subs) = [ sub | (sub, _) <- subs, sub `elem` exports ] -- Make a map from names to 'DeclInfo's. Exclude declarations that don't -- have names (instances and stand-alone documentation comments). Include -- subordinate names, but map them to their parent declarations. mkDeclMap :: [DeclInfo] -> Map Name DeclInfo mkDeclMap decls = Map.fromList . concat $ [ (declName d, (parent, doc, subs)) : subDecls | (parent@(L _ d), doc, subs) <- decls , let subDecls = [ (n, (parent, doc', [])) | (n, doc') <- subs ] , not (isDocD d), not (isInstD d) ] declInfos :: GlobalRdrEnv -> [(Decl, MaybeDocStrings)] -> ErrMsgM [DeclInfo] declInfos gre decls = forM decls $ \(parent@(L _ d), mbDocString) -> do mbDoc <- lexParseRnHaddockCommentList NormalHaddockComment gre mbDocString fnArgsDoc <- fmap (Map.mapMaybe id) $ Traversable.forM (getDeclFnArgDocs d) $ \doc -> lexParseRnHaddockComment NormalHaddockComment gre doc let subs_ = subordinates d subs <- forM subs_ $ \(subName, mbSubDocStr, subFnArgsDocStr) -> do mbSubDoc <- lexParseRnHaddockCommentList NormalHaddockComment gre mbSubDocStr subFnArgsDoc <- fmap (Map.mapMaybe id) $ Traversable.forM subFnArgsDocStr $ \doc -> lexParseRnHaddockComment NormalHaddockComment gre doc return (subName, (mbSubDoc, subFnArgsDoc)) return (parent, (mbDoc, fnArgsDoc), subs) subordinates :: HsDecl Name -> [(Name, MaybeDocStrings, Map Int HsDocString)] subordinates (TyClD d) = classDataSubs d subordinates _ = [] classDataSubs :: TyClDecl Name -> [(Name, MaybeDocStrings, Map Int HsDocString)] classDataSubs decl | isClassDecl decl = classSubs | isDataDecl decl = dataSubs | otherwise = [] where classSubs = [ (declName d, doc, fnArgsDoc) | (L _ d, doc) <- classDecls decl , let fnArgsDoc = getDeclFnArgDocs d ] dataSubs = constrs ++ fields where cons = map unL $ tcdCons decl -- should we use the type-signature of the constructor -- and the docs of the fields to produce fnArgsDoc for the constr, -- just in case someone exports it without exporting the type -- and perhaps makes it look like a function? I doubt it. constrs = [ (unL $ con_name c, maybeToList $ fmap unL $ con_doc c, Map.empty) | c <- cons ] fields = [ (unL n, maybeToList $ fmap unL doc, Map.empty) | RecCon flds <- map con_details cons , ConDeclField n _ doc <- flds ] -- All the sub declarations of a class (that we handle), ordered by -- source location, with documentation attached if it exists. classDecls :: TyClDecl Name -> [(Decl, MaybeDocStrings)] classDecls = filterDecls . collectDocs . sortByLoc . declsFromClass declsFromClass :: TyClDecl a -> [Located (HsDecl a)] declsFromClass class_ = docs ++ defs ++ sigs ++ ats where docs = mkDecls tcdDocs DocD class_ defs = mkDecls (bagToList . tcdMeths) ValD class_ sigs = mkDecls tcdSigs SigD class_ ats = mkDecls tcdATs TyClD class_ declName :: HsDecl a -> a declName (TyClD d) = tcdName d declName (ForD (ForeignImport n _ _)) = unLoc n -- we have normal sigs only (since they are taken from ValBindsOut) declName (SigD sig) = fromJust $ sigNameNoLoc sig declName _ = error "unexpected argument to declName" -- | The top-level declarations of a module that we care about, -- ordered by source location, with documentation attached if it exists. topDecls :: HsGroup Name -> [(Decl, MaybeDocStrings)] topDecls = filterClasses . filterDecls . collectDocs . sortByLoc . declsFromGroup filterOutInstances :: [(Located (HsDecl a), b, c)] -> [(Located (HsDecl a), b, c)] filterOutInstances = filter (\(L _ d, _, _) -> not (isInstD d)) -- | Take all declarations except pragmas, infix decls, rules and value -- bindings from an 'HsGroup'. declsFromGroup :: HsGroup Name -> [Decl] declsFromGroup group_ = mkDecls hs_tyclds TyClD group_ ++ mkDecls hs_derivds DerivD group_ ++ mkDecls hs_defds DefD group_ ++ mkDecls hs_fords ForD group_ ++ mkDecls hs_docs DocD group_ ++ mkDecls hs_instds InstD group_ ++ mkDecls (typesigs . hs_valds) SigD group_ where typesigs (ValBindsOut _ sigs) = filter isVanillaLSig sigs typesigs _ = error "expected ValBindsOut" -- | Take a field of declarations from a data structure and create HsDecls -- using the given constructor mkDecls :: (a -> [Located b]) -> (b -> c) -> a -> [Located c] mkDecls field con struct = [ L loc (con decl) | L loc decl <- field struct ] -- | Sort by source location sortByLoc :: [Located a] -> [Located a] sortByLoc = sortBy (comparing getLoc) warnAboutFilteredDecls :: Module -> [(LHsDecl Name, b, c)] -> ErrMsgM () warnAboutFilteredDecls mdl decls = do let modStr = moduleString mdl let typeInstances = nub [ tcdName d | (L _ (TyClD d), _, _) <- decls, isFamInstDecl d ] unless (null typeInstances) $ tell $ nub [ "Warning: " ++ modStr ++ ": Instances of type and data " ++ "families are not yet supported. Instances of the following families " ++ "will be filtered out:\n " ++ (concat $ intersperse ", " $ map (occNameString . nameOccName) typeInstances) ] let instances = nub [ pretty i | (L _ (InstD (InstDecl i _ _ ats)), _, _) <- decls , not (null ats) ] unless (null instances) $ tell $ nub [ "Warning: " ++ modStr ++ ": We do not support associated types in instances yet. " ++ "These instances are affected:\n" ++ (concat $ intersperse ", " instances) ] -------------------------------------------------------------------------------- -- Filtering of declarations -- -- We filter out declarations that we don't intend to handle later. -------------------------------------------------------------------------------- -- | Filter out declarations that we don't handle in Haddock filterDecls :: [(Decl, doc)] -> [(Decl, doc)] filterDecls decls = filter (isHandled . unL . fst) decls where isHandled (ForD (ForeignImport {})) = True isHandled (TyClD {}) = True isHandled (InstD {}) = True isHandled (SigD d) = isVanillaLSig (reL d) -- we keep doc declarations to be able to get at named docs isHandled (DocD _) = True isHandled _ = False -- | Go through all class declarations and filter their sub-declarations filterClasses :: [(Decl, doc)] -> [(Decl, doc)] filterClasses decls = [ if isClassD d then (L loc (filterClass d), doc) else x | x@(L loc d, doc) <- decls ] where filterClass (TyClD c) = TyClD $ c { tcdSigs = filter isVanillaLSig $ tcdSigs c } filterClass _ = error "expected TyClD" -------------------------------------------------------------------------------- -- Collect docs -- -- To be able to attach the right Haddock comment to the right declaration, -- we sort the declarations by their SrcLoc and "collect" the docs for each -- declaration. -------------------------------------------------------------------------------- type MaybeDocStrings = [HsDocString] -- avoid [] because we're appending from the left (quadratic), -- and avoid adding another package dependency for haddock, -- so use the difference-list pattern type MaybeDocStringsFast = MaybeDocStrings -> MaybeDocStrings docStringEmpty :: MaybeDocStringsFast docStringEmpty = id docStringSingleton :: HsDocString -> MaybeDocStringsFast docStringSingleton = (:) docStringAppend :: MaybeDocStringsFast -> MaybeDocStringsFast -> MaybeDocStringsFast docStringAppend = (.) docStringToList :: MaybeDocStringsFast -> MaybeDocStrings docStringToList = ($ []) -- | Collect the docs and attach them to the right declaration. collectDocs :: [Decl] -> [(Decl, MaybeDocStrings)] collectDocs = collect Nothing docStringEmpty collect :: Maybe Decl -> MaybeDocStringsFast -> [Decl] -> [(Decl, MaybeDocStrings)] collect d doc_so_far [] = case d of Nothing -> [] Just d0 -> finishedDoc d0 doc_so_far [] collect d doc_so_far (e:es) = case e of L _ (DocD (DocCommentNext str)) -> case d of Nothing -> collect d (docStringAppend doc_so_far (docStringSingleton str)) es Just d0 -> finishedDoc d0 doc_so_far (collect Nothing (docStringSingleton str) es) L _ (DocD (DocCommentPrev str)) -> collect d (docStringAppend doc_so_far (docStringSingleton str)) es _ -> case d of Nothing -> collect (Just e) doc_so_far es Just d0 -> finishedDoc d0 doc_so_far (collect (Just e) docStringEmpty es) -- This used to delete all DocD:s, unless doc was DocEmpty, -- which I suppose means you could kill a DocCommentNamed -- by: -- -- > -- | killer -- > -- > -- $victim -- -- Anyway I accidentally deleted the DocEmpty condition without -- realizing it was necessary for retaining some DocDs (at least -- DocCommentNamed), so I'm going to try just not testing any conditions -- and see if anything breaks. It really shouldn't break anything -- to keep more doc decls around, IMHO. -- -- -Isaac finishedDoc :: Decl -> MaybeDocStringsFast -> [(Decl, MaybeDocStrings)] -> [(Decl, MaybeDocStrings)] finishedDoc d doc rest = (d, docStringToList doc) : rest {- attachATs :: [IE Name] -> ([IE Name], [Name]) attachATs exports = where ats = <- export ] -} -- | Build the list of items that will become the documentation, from the -- export list. At this point, the list of ExportItems is in terms of -- original names. -- -- We create the export items even if the module is hidden, since they -- might be useful when creating the export items for other modules. mkExportItems :: ModuleMap -> Module -- this module -> GlobalRdrEnv -> [Name] -- exported names (orig) -> [DeclInfo] -> Map Name DeclInfo -- maps local names to declarations -> [DocOption] -> Maybe [IE Name] -> Bool -- --ignore-all-exports flag -> [Instance] -> InstIfaceMap -> ErrMsgGhc [ExportItem Name] mkExportItems modMap this_mod gre exported_names decls declMap opts maybe_exps ignore_all_exports _ instIfaceMap | isNothing maybe_exps || ignore_all_exports || OptIgnoreExports `elem` opts = everything_local_exported | otherwise = liftM concat $ mapM lookupExport (fromJust maybe_exps) where -- creating export items for intsances (unfinished experiment) -- instances = [ d | d@(L _ decl, _, _) <- decls, isInstD decl ] everything_local_exported = -- everything exported liftErrMsg $ fullContentsOfThisModule gre decls lookupExport (IEVar x) = declWith x lookupExport (IEThingAbs t) = declWith t -- | Just fam <- Map.lookup t famMap = absFam fam -- | otherwise = declWith t -- where -- absFam (Just (famDecl, doc), instances) = return $ [ ExportDecl famDecl doc [] ] ++ matchingInsts t -- absFam (Nothing, instances) = lookupExport (IEThingAll t) = declWith t lookupExport (IEThingWith t _) = declWith t lookupExport (IEModuleContents m) = fullContentsOf m lookupExport (IEGroup lev docStr) = liftErrMsg $ do ifDoc (lexParseRnHaddockComment DocSectionComment gre docStr) (\doc -> return [ ExportGroup lev "" doc ]) lookupExport (IEDoc docStr) = liftErrMsg $ do ifDoc (lexParseRnHaddockComment NormalHaddockComment gre docStr) (\doc -> return [ ExportDoc doc ]) lookupExport (IEDocNamed str) = liftErrMsg $ do ifDoc (findNamedDoc str [ unL d | (d,_,_) <- decls ]) (\docStr -> ifDoc (lexParseRnHaddockComment NormalHaddockComment gre docStr) (\doc -> return [ ExportDoc doc ])) ifDoc :: (Monad m) => m (Maybe a) -> (a -> m [b]) -> m [b] ifDoc parse finish = do mbDoc <- parse case mbDoc of Nothing -> return []; Just doc -> finish doc declWith :: Name -> ErrMsgGhc [ ExportItem Name ] declWith t = case findDecl t of Just x@(decl,_,_) -> let declName_ = case getMainDeclBinder (unL decl) of Just n -> n Nothing -> error "declWith: should not happen" in case () of _ -- temp hack: we filter out separately exported ATs, since we haven't decided how -- to handle them yet. We should really give an warning message also, and filter the -- name out in mkVisibleNames... | t `elem` declATs (unL decl) -> return [] -- We should not show a subordinate by itself if any of its -- parents is also exported. See note [1]. | t /= declName_, Just p <- find isExported (parents t $ unL decl) -> do liftErrMsg $ tell [ "Warning: " ++ moduleString this_mod ++ ": " ++ pretty (nameOccName t) ++ " is exported separately but " ++ "will be documented under " ++ pretty (nameOccName p) ++ ". Consider exporting it together with its parent(s)" ++ " for code clarity." ] return [] -- normal case | otherwise -> return [ mkExportDecl t x ] Nothing -> -- If we can't find the declaration, it must belong to another package. -- We return just the name of the declaration and try to get the subs -- from the installed interface of that package. case Map.lookup (nameModule t) instIfaceMap of -- It's Nothing in the cases where Haddock has already warned -- the user: "Warning: The documentation for the following -- packages are not installed. No links will be generated to -- these packages: ..." Nothing -> return [ ExportNoDecl t [] ] Just iface -> let subs = case Map.lookup t (instSubMap iface) of Nothing -> [] Just x -> x in -- If we couldn't find out the decl, we would have to -- return [ ExportNoDecl t subs ] -- . But we can find out the decl, because we have the -- Name and the imported module's .hi files for -- reference! do mbTyThing <- liftGhcToErrMsgGhc $ lookupName t case mbTyThing of Nothing -> do liftErrMsg (tell ["Why was no tything found for " ++ pretty (nameOccName t) ++ "? We found its module's docs. Is this a Haddock bug?"]) return [ ExportNoDecl t subs ] Just tyThing -> do let hsdecl = tyThingToHsSynSig tyThing return [ mkExportDecl t ( hsdecl , (fmap (fmapHsDoc getName) $ Map.lookup t (instDocMap iface), Map.empty{-todo-}) , map (\subt -> ( subt , (fmap (fmapHsDoc getName) $ Map.lookup subt (instDocMap iface), Map.empty{-todo-}) ) ) subs )] mkExportDecl :: Name -> DeclInfo -> ExportItem Name mkExportDecl n (decl, doc, subs) = decl' where decl' = ExportDecl (restrictTo sub_names (extractDecl n mdl decl)) doc subs' [] mdl = nameModule n subs' = filter ((`elem` exported_names) . fst) subs sub_names = map fst subs' isExported n = n `elem` exported_names fullContentsOf modname | m == this_mod = liftErrMsg $ fullContentsOfThisModule gre decls | otherwise = case Map.lookup m modMap of Just iface | OptHide `elem` ifaceOptions iface -> return (ifaceExportItems iface) | otherwise -> return [ ExportModule m ] Nothing -> -- we have to try to find it in the installed interfaces -- (external packages) case Map.lookup modname (Map.mapKeys moduleName instIfaceMap) of Just iface -> return [ ExportModule (instMod iface) ] Nothing -> do liftErrMsg $ tell ["Warning: " ++ pretty this_mod ++ ": Could not find " ++ "documentation for exported module: " ++ pretty modname] return [] where m = mkModule packageId modname packageId = modulePackageId this_mod findDecl :: Name -> Maybe DeclInfo findDecl n | m == this_mod = Map.lookup n declMap | otherwise = case Map.lookup m modMap of Just iface -> Map.lookup n (ifaceDeclMap iface) Nothing -> Nothing where m = nameModule n -- Note [1]: ------------ -- It is unnecessary to document a subordinate by itself at the top level if -- any of its parents is also documented. Furthermore, if the subordinate is a -- record field or a class method, documenting it under its parent -- indicates its special status. -- -- A user might expect that it should show up separately, so we issue a -- warning. It's a fine opportunity to also tell the user she might want to -- export the subordinate through the parent export item for clarity. -- -- The code removes top-level subordinates also when the parent is exported -- through a 'module' export. I think that is fine. -- -- (For more information, see Trac #69) fullContentsOfThisModule :: GlobalRdrEnv -> [DeclInfo] -> ErrMsgM [ExportItem Name] fullContentsOfThisModule gre decls = liftM catMaybes $ mapM mkExportItem decls where mkExportItem (L _ (DocD (DocGroup lev docStr)), _, _) = do mbDoc <- lexParseRnHaddockComment DocSectionComment gre docStr return $ fmap (\doc -> ExportGroup lev "" doc) mbDoc mkExportItem (L _ (DocD (DocCommentNamed _ docStr)), _, _) = do mbDoc <- lexParseRnHaddockComment NormalHaddockComment gre docStr return $ fmap ExportDoc mbDoc mkExportItem (decl, doc, subs) = return $ Just $ ExportDecl decl doc subs [] -- | Sometimes the declaration we want to export is not the "main" declaration: -- it might be an individual record selector or a class method. In these -- cases we have to extract the required declaration (and somehow cobble -- together a type signature for it...) extractDecl :: Name -> Module -> Decl -> Decl extractDecl name mdl decl | Just n <- getMainDeclBinder (unLoc decl), n == name = decl | otherwise = case unLoc decl of TyClD d | isClassDecl d -> let matches = [ sig | sig <- tcdSigs d, sigName sig == Just name, isVanillaLSig sig ] -- TODO: document fixity -- let assocMathes = [ tyDecl | at <- tcdATs d, ] in case matches of [s0] -> let (n, tyvar_names) = name_and_tyvars d L pos sig = extractClassDecl n tyvar_names s0 in L pos (SigD sig) _ -> error "internal: extractDecl" TyClD d | isDataDecl d -> let (n, tyvar_names) = name_and_tyvars d L pos sig = extractRecSel name mdl n tyvar_names (tcdCons d) in L pos (SigD sig) _ -> error "internal: extractDecl" where name_and_tyvars d = (unLoc (tcdLName d), hsLTyVarLocNames (tcdTyVars d)) toTypeNoLoc :: Located Name -> LHsType Name toTypeNoLoc = noLoc . HsTyVar . unLoc extractClassDecl :: Name -> [Located Name] -> LSig Name -> LSig Name extractClassDecl c tvs0 (L pos (TypeSig lname ltype)) = case ltype of L _ (HsForAllTy expl tvs (L _ preds) ty) -> L pos (TypeSig lname (noLoc (HsForAllTy expl tvs (lctxt preds) ty))) _ -> L pos (TypeSig lname (noLoc (mkImplicitHsForAllTy (lctxt []) ltype))) where lctxt = noLoc . ctxt ctxt preds = noLoc (HsClassP c (map toTypeNoLoc tvs0)) : preds extractClassDecl _ _ _ = error "extractClassDecl: unexpected decl" extractRecSel :: Name -> Module -> Name -> [Located Name] -> [LConDecl Name] -> LSig Name extractRecSel _ _ _ _ [] = error "extractRecSel: selector not found" extractRecSel nm mdl t tvs (L _ con : rest) = case con_details con of RecCon fields | (ConDeclField n ty _ : _) <- matching_fields fields -> L (getLoc n) (TypeSig (noLoc nm) (noLoc (HsFunTy data_ty (getBangType ty)))) _ -> extractRecSel nm mdl t tvs rest where matching_fields flds = [ f | f@(ConDeclField n _ _) <- flds, unLoc n == nm ] data_ty = foldl (\x y -> noLoc (HsAppTy x y)) (noLoc (HsTyVar t)) (map toTypeNoLoc tvs) -- Pruning pruneExportItems :: [ExportItem Name] -> [ExportItem Name] pruneExportItems items = filter hasDoc items where hasDoc (ExportDecl{expItemMbDoc = (d, _)}) = isJust d hasDoc _ = True mkVisibleNames :: [ExportItem Name] -> [DocOption] -> [Name] mkVisibleNames exports opts | OptHide `elem` opts = [] | otherwise = concatMap exportName exports where exportName e@ExportDecl {} = case getMainDeclBinder $ unL $ expItemDecl e of Just n -> n : subs Nothing -> subs where subs = map fst (expItemSubDocs e) exportName ExportNoDecl {} = [] -- we don't count these as visible, since -- we don't want links to go to them. exportName _ = [] -- | Find a stand-alone documentation comment by its name findNamedDoc :: String -> [HsDecl Name] -> ErrMsgM (Maybe HsDocString) findNamedDoc name decls = search decls where search [] = do tell ["Cannot find documentation for: $" ++ name] return Nothing search ((DocD (DocCommentNamed name' doc)):rest) | name == name' = return (Just doc) | otherwise = search rest search (_other_decl : rest) = search rest