{-# OPTIONS_GHC -fglasgow-exts #-} -- -- Haddock - A Haskell Documentation Tool -- -- (c) Simon Marlow 2003 -- module Main (main) where import Binary import Digraph --import HaddockDB -- not compiling import HaddockHtml import HaddockLex import HaddockParse import HaddockRename import HaddockTypes import HaddockUtil import HaddockVersion import HsParseMonad import HsParser import HsSyn import Map ( Map ) import qualified Map hiding ( Map ) import Set import Paths_Haddock ( getDataDir ) import Control.Exception ( bracket ) import Control.Monad ( when ) import Control.Monad.Writer ( Writer, runWriter, tell ) import Data.Char ( isSpace ) import Data.IORef ( writeIORef ) import Data.List ( nub, (\\), foldl', sortBy ) import Data.Maybe ( isJust, isNothing, maybeToList, listToMaybe ) --import Debug.Trace import System.Console.GetOpt ( getOpt, usageInfo, ArgOrder(..), OptDescr(..), ArgDescr(..) ) import System.Environment ( getArgs ) import System.IO ( stderr, IOMode(..), openFile, hClose, hGetContents, hPutStrLn ) #if defined(mingw32_HOST_OS) import Foreign import Foreign.C #endif #if __GLASGOW_HASKELL__ >= 603 import System.Process import System.Exit import Control.Exception ( Exception(..), throwIO, catch ) import Prelude hiding (catch) import System.Directory ( doesDirectoryExist, doesFileExist ) import Control.Concurrent #endif ----------------------------------------------------------------------------- -- Top-level stuff main :: IO () main = do cmdline <- getArgs case getOpt Permute options cmdline of (flags, args, [] ) -> run flags args (_, _, errors) -> do prog <- getProgramName die (concat errors ++ usageInfo (usageHeader prog) options) usageHeader :: String -> String usageHeader prog = "Usage: " ++ prog ++ " [OPTION...] file...\n" data Flag = Flag_CSS String | Flag_Debug -- | Flag_DocBook | Flag_DumpInterface FilePath | Flag_Heading String | Flag_Package String | Flag_Html | Flag_HtmlHelp String | Flag_Lib String | Flag_NoImplicitPrelude | Flag_OutputDir FilePath | Flag_Prologue FilePath | Flag_ReadInterface FilePath | Flag_SourceBaseURL String | Flag_SourceModuleURL String | Flag_SourceEntityURL String | Flag_WikiBaseURL String | Flag_WikiModuleURL String | Flag_WikiEntityURL String | Flag_Help | Flag_Verbose | Flag_Version | Flag_UseContents String | Flag_GenContents | Flag_UseIndex String | Flag_GenIndex | Flag_IgnoreAllExports | Flag_HideModule String | Flag_UsePackage String deriving (Eq) options :: [OptDescr Flag] options = [ Option ['o'] ["odir"] (ReqArg Flag_OutputDir "DIR") "directory in which to put the output files", Option ['i'] ["read-interface"] (ReqArg Flag_ReadInterface "FILE") "read an interface from FILE", Option ['D'] ["dump-interface"] (ReqArg Flag_DumpInterface "FILE") "dump an interface for these modules in FILE", Option ['l'] ["lib"] (ReqArg Flag_Lib "DIR") "location of Haddock's auxiliary files", -- Option ['S'] ["docbook"] (NoArg Flag_DocBook) -- "output in DocBook XML", Option ['h'] ["html"] (NoArg Flag_Html) "output in HTML", Option [] ["html-help"] (ReqArg Flag_HtmlHelp "format") "produce index and table of contents in mshelp, mshelp2 or devhelp format (with -h)", Option [] ["source-base"] (ReqArg Flag_SourceBaseURL "URL") "URL for a source code link on the contents\nand index pages", Option ['s'] ["source", "source-module"] (ReqArg Flag_SourceModuleURL "URL") "URL for a source code link for each module\n(using the %{FILE} or %{MODULE} vars)", Option [] ["source-entity"] (ReqArg Flag_SourceEntityURL "URL") "URL for a source code link for each entity\n(using the %{FILE}, %{MODULE} or %{NAME} vars)", Option [] ["comments-base"] (ReqArg Flag_WikiBaseURL "URL") "URL for a comments link on the contents\nand index pages", Option [] ["comments-module"] (ReqArg Flag_WikiModuleURL "URL") "URL for a comments link for each module\n(using the %{MODULE} var)", Option [] ["comments-entity"] (ReqArg Flag_WikiEntityURL "URL") "URL for a comments link for each entity\n(using the %{FILE}, %{MODULE} or %{NAME} vars)", Option ['c'] ["css"] (ReqArg Flag_CSS "FILE") "the CSS file to use for HTML output", Option ['p'] ["prologue"] (ReqArg Flag_Prologue "FILE") "file containing prologue text", Option ['t'] ["title"] (ReqArg Flag_Heading "TITLE") "page heading", Option ['k'] ["package"] (ReqArg Flag_Package "PACKAGE") "package name (optional)", Option ['n'] ["no-implicit-prelude"] (NoArg Flag_NoImplicitPrelude) "do not assume Prelude is imported", Option ['d'] ["debug"] (NoArg Flag_Debug) "extra debugging output", Option ['?'] ["help"] (NoArg Flag_Help) "display this help and exit", Option ['V'] ["version"] (NoArg Flag_Version) "output version information and exit", Option ['v'] ["verbose"] (NoArg Flag_Verbose) "increase verbosity", Option [] ["use-contents"] (ReqArg Flag_UseContents "URL") "use a separately-generated HTML contents page", Option [] ["gen-contents"] (NoArg Flag_GenContents) "generate an HTML contents from specified interfaces", Option [] ["use-index"] (ReqArg Flag_UseIndex "URL") "use a separately-generated HTML index", Option [] ["gen-index"] (NoArg Flag_GenIndex) "generate an HTML index from specified interfaces", Option [] ["ignore-all-exports"] (NoArg Flag_IgnoreAllExports) "behave as if all modules have the ignore-exports atribute", Option [] ["hide"] (ReqArg Flag_HideModule "M") "behave as if module M has the hide attribute", Option [] ["use-package"] (ReqArg Flag_UsePackage "P") "the modules being processed depend on package P" ] run :: [Flag] -> [FilePath] -> IO () run flags files = do when (Flag_Help `elem` flags) $ do prog <- getProgramName bye (usageInfo (usageHeader prog) options) when (Flag_Version `elem` flags) $ bye ("Haddock version " ++ projectVersion ++ ", (c) Simon Marlow 2003\n") let title = case [str | Flag_Heading str <- flags] of [] -> "" (t:_) -> t package = listToMaybe [str | Flag_Package str <- flags] maybe_source_urls = (listToMaybe [str | Flag_SourceBaseURL str <- flags] ,listToMaybe [str | Flag_SourceModuleURL str <- flags] ,listToMaybe [str | Flag_SourceEntityURL str <- flags]) maybe_wiki_urls = (listToMaybe [str | Flag_WikiBaseURL str <- flags] ,listToMaybe [str | Flag_WikiModuleURL str <- flags] ,listToMaybe [str | Flag_WikiEntityURL str <- flags]) verbose = Flag_Verbose `elem` flags libdir <- case [str | Flag_Lib str <- flags] of [] -> getDataDir -- provided by Cabal fs -> return (last fs) let css_file = case [str | Flag_CSS str <- flags] of [] -> Nothing fs -> Just (last fs) odir <- case [str | Flag_OutputDir str <- flags] of [] -> return "." fs -> return (last fs) let dump_iface = case [str | Flag_DumpInterface str <- flags] of [] -> Nothing fs -> Just (last fs) read_iface_flags = [ parseIfaceOption str | Flag_ReadInterface str <- flags ] maybe_contents_url = case [url | Flag_UseContents url <- flags] of [] -> Nothing us -> Just (last us) maybe_index_url = case [url | Flag_UseIndex url <- flags] of [] -> Nothing us -> Just (last us) maybe_html_help_format = case [hhformat | Flag_HtmlHelp hhformat <- flags] of [] -> Nothing formats -> Just (last formats) prologue <- getPrologue flags -- grok the --use-package flags pkg_ifaces_to_read <- getPackageIfaces flags verbose let ifaces_to_read = read_iface_flags ++ pkg_ifaces_to_read read_iface_stuff <- mapM readIface (map snd ifaces_to_read) let (read_ifacess, doc_envs) = unzip read_iface_stuff read_ifaces = concat read_ifacess ext_doc_env = Map.unions doc_envs visible_read_ifaces = filter ((OptHide `notElem`) . iface_options) read_ifaces external_mods = map iface_module read_ifaces pkg_paths = map fst ifaces_to_read updateHTMLXRefs pkg_paths read_ifacess when ((Flag_GenIndex `elem` flags || Flag_GenContents `elem` flags) && Flag_Html `elem` flags) $ die ("-h cannot be used with --gen-index or --gen-contents") when (Flag_GenContents `elem` flags) $ do ppHtmlContents odir title package maybe_html_help_format maybe_index_url maybe_source_urls maybe_wiki_urls visible_read_ifaces prologue copyHtmlBits odir libdir css_file when (Flag_GenIndex `elem` flags) $ do ppHtmlIndex odir title package maybe_html_help_format maybe_contents_url maybe_source_urls maybe_wiki_urls visible_read_ifaces copyHtmlBits odir libdir css_file when (Flag_GenContents `elem` flags && Flag_GenIndex `elem` flags) $ do ppHtmlHelpFiles title package visible_read_ifaces odir maybe_html_help_format pkg_paths parsed_mods <- mapM parse_file files sorted_mod_files <- sortModules (zip parsed_mods files) -- emits an error message if there are recursive modules -- process the modules in sorted order, building up a mapping from -- modules to interfaces. let loop mod_env ifaces [] = return (reverse ifaces) loop mod_env ifaces ((hsmod,file):mdls) = do let (iface,msgs) = runWriter $ mkInterfacePhase1 flags verbose mod_env file package hsmod new_mod_env = Map.insert (iface_module iface) iface mod_env mapM_ (hPutStrLn stderr) msgs loop new_mod_env (iface:ifaces) mdls let mod_map = Map.fromList [ (iface_module iface,iface) | iface <- read_ifaces ] ifaces <- loop mod_map read_ifaces sorted_mod_files let these_ifaces0 = [ iface | iface <- ifaces, iface_module iface `notElem` external_mods ] let these_ifaces1 = attachInstances these_ifaces0 this_doc_env = buildGlobalDocEnv these_ifaces1 global_doc_env = this_doc_env `Map.union` ext_doc_env `Map.union` builtinDocEnv -- Now do phase 2 let loop2 ifaces [] = return (reverse ifaces) loop2 ifaces (iface:rest) = do let (iface',msgs) = runWriter $ mkInterfacePhase2 verbose iface global_doc_env mapM_ (hPutStrLn stderr) msgs loop2 (iface':ifaces) rest these_ifaces <- loop2 [] these_ifaces1 -- when (Flag_DocBook `elem` flags) $ -- putStr (ppDocBook odir mod_ifaces) when (Flag_Debug `elem` flags) $ do mapM_ putStrLn (map show [ (iface_module i, Map.toAscList (iface_env i), Map.toAscList (iface_sub i)) | i <- these_ifaces ]) when (Flag_Html `elem` flags) $ do ppHtml title package these_ifaces odir prologue maybe_html_help_format maybe_source_urls maybe_wiki_urls maybe_contents_url maybe_index_url copyHtmlBits odir libdir css_file -- dump an interface if requested case dump_iface of Nothing -> return () Just fn -> dumpInterfaces these_ifaces this_doc_env fn parseIfaceOption :: String -> (FilePath,FilePath) parseIfaceOption s = case break (==',') s of (fpath,',':file) -> (fpath,file) (file, _) -> ("", file) updateHTMLXRefs :: [FilePath] -> [[Interface]] -> IO () updateHTMLXRefs paths ifaces_s = writeIORef html_xrefs_ref (Map.fromList mapping) where mapping = [ (iface_module iface, fpath) | (fpath, ifaces) <- zip paths ifaces_s, iface <- ifaces ] parse_file :: FilePath -> IO HsModule parse_file file = do bracket (openFile file ReadMode) (\h -> hClose h) (\h -> do stuff <- hGetContents h case parse stuff (SrcLoc 1 1 file) 1 0 file [] of Ok _ e -> return e Failed err -> die (file ++ ':':err ++ "\n") ) getPrologue :: [Flag] -> IO (Maybe Doc) getPrologue flags = case [filename | Flag_Prologue filename <- flags ] of [] -> return Nothing [filename] -> do str <- readFile filename case parseParas (tokenise str) of Left err -> dieMsg err Right doc -> return (Just doc) _otherwise -> dieMsg "multiple -p/--prologue options" -- --------------------------------------------------------------------------- -- External packages getPackageIfaces :: [Flag] -> Bool -> IO [(String,String)] getPackageIfaces flags verbose = let pkgs = [pkg | Flag_UsePackage pkg <- flags] in #if __GLASGOW_HASKELL__ < 603 if (not (null pkgs)) then die ("-use-package not supported; recompile Haddock with GHC 6.4 or later") else return [] #else do mb_iface_details <- mapM getPkgIface pkgs return [ ok | Just ok <- mb_iface_details ] where hc_pkg = "ghc-pkg" -- ToDo: flag getPkgIface pkg = do when verbose $ putStrLn ("querying ghc-pkg for " ++ pkg ++ "...") getPkgIface' pkg `catch` (\e -> do putStrLn ("Warning: cannot use package " ++ pkg ++ ":") putStrLn (" " ++ show e) return Nothing) getPkgIface' pkg = do html <- getPkgField pkg "haddock-html" html_exists <- doesDirectoryExist html when (not html_exists) $ do throwIO (ErrorCall ("HTML directory " ++ html ++ " does not exist.")) iface <- getPkgField pkg "haddock-interfaces" iface_exists <- doesFileExist iface when (not iface_exists) $ do throwIO (ErrorCall ("interface " ++ iface ++ " does not exist.")) return (Just (html, iface)) getPkgField pkg field = do (hin,hout,herr,p) <- runInteractiveProcess hc_pkg ["field", pkg, field] Nothing Nothing hClose hin out <- hGetContents hout forkIO (hGetContents herr >> return ()) -- just sink the stderr r <- waitForProcess p when (r /= ExitSuccess) $ throwIO (ErrorCall ("ghc-pkg failed")) let value = dropWhile isSpace $ init $ tail $ dropWhile (/=':') out when verbose $ putStrLn (" " ++ field ++ ": " ++ value) return value #endif ----------------------------------------------------------------------------- -- Figuring out the definitions that are exported from a module -- We're going to make interfaces in two passes: -- -- 1. Rename the code. This basically involves resolving all -- the names to "original names". -- -- 2. Convert all the entity references to "doc names". These are -- the names we want to link to in the documentation. mkInterfacePhase1 :: [Flag] -> Bool -- verbose -> ModuleMap -> FilePath -> Maybe String -> HsModule -> ErrMsgM Interface -- the "interface" of the module mkInterfacePhase1 flags verbose mod_map filename package (HsModule (SrcLoc _ _ orig_filename) mdl exps imps decls maybe_opts maybe_info maybe_doc) = do let no_implicit_prelude = Flag_NoImplicitPrelude `elem` flags ignore_all_exports = Flag_IgnoreAllExports `elem` flags -- Process the options, if available opts0 <- case maybe_opts of Just opt_str -> processOptions opt_str Nothing -> return [] let -- check for a --hide option Module mod_str = mdl opts | Flag_HideModule mod_str `elem` flags = OptHide : opts0 | otherwise = opts0 let -- expand type signatures with multiple variables into multiple -- type signatures expanded_decls = concat (map expandDecl decls) sub_map = mkSubNames expanded_decls -- first, attach documentation to declarations annotated_decls = collectDoc expanded_decls -- now find the defined names locally_defined_names = collectNames annotated_decls qual_local_names = map (Qual mdl) locally_defined_names unqual_local_names = map UnQual locally_defined_names local_orig_env = Map.fromList (zip unqual_local_names qual_local_names ++ zip qual_local_names qual_local_names) -- both qualified and unqualifed names are in scope for local things implicit_imps | no_implicit_prelude || any is_prel_import imps = imps | otherwise = HsImportDecl loc prelude_mod False Nothing Nothing : imps where loc = SrcLoc 0 0 "" is_prel_import (HsImportDecl _ mdl0 _ _ _ ) = mdl0 == prelude_mod -- in -- build the orig_env, which maps names to *original* names (so we can -- find the original declarations & docs for things). imported_orig_env <- buildOrigEnv mdl verbose mod_map implicit_imps let orig_env = local_orig_env `Map.union` imported_orig_env -- convert names in source code to original, fully qualified, names (orig_exports, missing_names1) = runRnFM orig_env (mapMaybeM renameExportList exps) (orig_decls, missing_names2) = runRnFM orig_env (mapM renameDecl annotated_decls) (orig_module_doc, missing_names3) = runRnFM orig_env (renameMaybeDoc maybe_doc) decl_map :: Map HsName HsDecl decl_map = Map.fromList [ (n,d) | d <- orig_decls, n <- declBinders d ] instances = [ d | d@HsInstDecl{} <- orig_decls ] ++ [ d | decl <- orig_decls, d <- derivedInstances mdl decl] -- trace (show (Map.toAscList orig_env)) $ do -- gather up a list of entities that are exported (original names) (exported_names, exported_visible_names) <- exportedNames mdl mod_map locally_defined_names orig_env sub_map orig_exports opts let -- maps exported HsNames to orig HsQNames name_env = Map.fromList [ (nameOfQName n, n) | n <- exported_names ] -- find the names exported by this module that other modules should *not* -- link to. reexports = [ nm | n@(Qual _ nm) <- exported_names, n `notElem` exported_visible_names ] -- in -- make the "export items", which will be converted into docs later orig_export_items <- mkExportItems mod_map mdl exported_names decl_map sub_map orig_decls opts orig_exports ignore_all_exports let -- prune the export list to just those declarations that have -- documentation, if the 'prune' option is on. pruned_export_list | OptPrune `elem` opts = pruneExportItems orig_export_items | otherwise = orig_export_items -- in -- report any names we couldn't find/resolve let missing_names = missing_names1 ++ missing_names2 ++ missing_names3 --ignore missing_names3 & missing_names5 for now filtered_missing_names = filter (`notElem` builtinNames) missing_names name_strings = nub (map show filtered_missing_names) -- in when (OptHide `notElem` opts && not (null name_strings)) $ tell ["Warning: " ++ show mdl ++ ": the following names could not be resolved:\n"++ " " ++ concat (map (' ':) name_strings) ] return (Interface { iface_filename = filename, iface_orig_filename= orig_filename, iface_module = mdl, iface_package = package, iface_env = name_env, iface_reexported = reexports, iface_sub = sub_map, iface_orig_exports = pruned_export_list, iface_decls = decl_map, iface_info = maybe_info, iface_doc = orig_module_doc, iface_options = opts, iface_exports = error "iface_exports", iface_insts = instances } ) -- ----------------------------------------------------------------------------- -- Phase 2 mkInterfacePhase2 :: Bool -- verbose -> Interface -> Map HsQName HsQName -- global doc-name mapping -> ErrMsgM Interface mkInterfacePhase2 verbose iface gbl_doc_env = case iface of { Interface { iface_module = this_mdl, iface_env = env, iface_reexported = reexports, iface_orig_exports = orig_export_items, iface_doc = orig_module_doc } -> let exported_visible_names = [orig | (nm,orig) <- Map.toAscList env, nm `notElem` reexports ] -- build the import_env. import_env = foldl fn gbl_doc_env exported_visible_names where fn env qnm@(Qual _ nm) = Map.insert qnm (Qual this_mdl nm) env fn env (UnQual nm) = env -- rename names in the exported declarations to point to things that -- are closer, or maybe even exported by, the current module. (renamed_export_list, missing_names1) = runRnUnqualFM import_env (renameExportItems orig_export_items) (final_module_doc, missing_names2) = runRnUnqualFM import_env (renameMaybeDoc orig_module_doc) -- we're only interested in reporting missing *qualfied* -- names, the unqualified ones are the ones that couldn't -- be resolved in phase 1 and have already been reported. filtered_missing_names = filter isQual (missing_names1 ++ missing_names2) where isQual (Qual _ _) = True isQual _ = False missing_names = map show (nub filtered_missing_names) in do -- report things that we couldn't link to. Only do this -- for non-hidden modules. when (OptHide `notElem` iface_options iface && not (null missing_names)) $ tell ["Warning: " ++ show this_mdl ++ ": could not find link destinations for:\n"++ " " ++ concat (map (' ':) missing_names) ] -- trace (show (Map.toAscList import_env)) $ do return iface{ iface_exports = renamed_export_list, iface_doc = final_module_doc } } -- ----------------------------------------------------------------------------- -- Try to generate instance declarations for derived instances. -- We can't do this properly without instance inference, but if a type -- variable occurs as a constructor argument, then we can just -- propagate the derived class to the variable. But we know nothing of -- the constraints on any type variables that occur elsewhere. -- Note that a type variable may be in both categories: then we know a -- constraint, but there may be more, or a stronger constraint. derivedInstances :: Module -> HsDecl -> [HsDecl] derivedInstances mdl decl = case decl of HsDataDecl srcloc ctxt n tvs cons drv@(_:_) _ -> derived srcloc ctxt n tvs cons drv HsNewTypeDecl srcloc ctxt n tvs con drv@(_:_) _ -> derived srcloc ctxt n tvs [con] drv _ -> [] where derived srcloc ctxt n tvs cons drv = [HsInstDecl srcloc (ctxt ++ [(cls,[v]) | v <- simple_tvars] ++ extra_constraint) (cls,[lhs]) [] | cls <- drv] where targs = map stripDocs (targsConstrs cons) -- a type variable is simple if it occurs as a data constructor argument simple_tvars = map HsTyVar $ Set.elems $ Set.fromList $ [tv | HsTyVar tv <- targs] -- a type variable is complex if it occurs inside a data constructor -- argument, except where the argument is identical to the lhs. complex_tvars = map HsTyVar $ Set.elems $ Set.unions $ map tvarsType $ filter (/= lhs) $ filter (not . isVar) targs isVar (HsTyVar _) = True isVar _ = False extra_constraint | null complex_tvars = [] | otherwise = [(unknownConstraint,complex_tvars)] lhs | n == tuple_tycon_name (length tvs - 1) = HsTyTuple True (map HsTyVar tvs) | otherwise = foldl HsTyApp (HsTyCon (Qual mdl n)) (map HsTyVar tvs) -- collect type arguments of constructors targsConstrs :: [HsConDecl] -> [HsType] targsConstrs = foldr targsConstr [] targsConstr :: HsConDecl -> [HsType] -> [HsType] targsConstr (HsConDecl _ _ _ _ bts _) ts = foldr targsBangType ts bts targsConstr (HsRecDecl _ _ _ _ fs _) ts = foldr targsField ts fs targsField (HsFieldDecl _ bt _) = targsBangType bt targsBangType (HsBangedTy t) ts = t : ts targsBangType (HsUnBangedTy t) ts = t : ts -- remove documentation comments from a type stripDocs :: HsType -> HsType stripDocs (HsForAllType n ctxt t) = HsForAllType n ctxt (stripDocs t) stripDocs (HsTyFun t1 t2) = HsTyFun (stripDocs t1) (stripDocs t2) stripDocs (HsTyTuple boxed ts) = HsTyTuple boxed (map stripDocs ts) stripDocs (HsTyApp t1 t2) = HsTyApp (stripDocs t1) (stripDocs t2) stripDocs (HsTyDoc t _) = stripDocs t stripDocs (HsTyIP n t) = HsTyIP n (stripDocs t) stripDocs t = t -- collect the type variables occurring free in a type tvarsType (HsForAllType (Just tvs) _ t) = foldl (flip Set.delete) (tvarsType t) tvs tvarsType (HsForAllType Nothing _ t) = tvarsType t tvarsType (HsTyFun t1 t2) = tvarsType t1 `Set.union` tvarsType t2 tvarsType (HsTyTuple _ ts) = Set.unions (map tvarsType ts) tvarsType (HsTyApp t1 t2) = tvarsType t1 `Set.union` tvarsType t2 tvarsType (HsTyVar tv) = Set.singleton tv tvarsType (HsTyCon _) = Set.empty tvarsType (HsTyDoc t _) = tvarsType t tvarsType (HsTyIP _ t) = tvarsType t unknownConstraint :: HsQName unknownConstraint = UnQual (HsTyClsName (HsIdent "???")) -- ----------------------------------------------------------------------------- -- 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. mkExportItems :: ModuleMap -> Module -- this module -> [HsQName] -- exported names (orig) -> Map HsName HsDecl -- maps local names to declarations -> Map HsName [HsName] -- sub-map for this module -> [HsDecl] -- decls in the current module -> [DocOption] -> Maybe [HsExportSpec] -> Bool -- --ignore-all-exports flag -> ErrMsgM [ExportItem] mkExportItems mod_map this_mod exported_names decl_map sub_map decls opts maybe_exps ignore_all_exports | isNothing maybe_exps || ignore_all_exports || OptIgnoreExports `elem` opts = everything_local_exported | Just specs <- maybe_exps = do exps <- mapM lookupExport specs return (concat exps) where everything_local_exported = -- everything exported return (fullContentsOfThisModule this_mod decls) lookupExport (HsEVar x) = declWith x lookupExport (HsEAbs t) = declWith t lookupExport (HsEThingAll t) = declWith t lookupExport (HsEThingWith t cs) = declWith t lookupExport (HsEModuleContents m) = fullContentsOf m lookupExport (HsEGroup lev doc) = return [ ExportGroup lev "" doc ] lookupExport (HsEDoc doc) = return [ ExportDoc doc ] lookupExport (HsEDocNamed str) = do r <- findNamedDoc str decls case r of Nothing -> return [] Just found -> return [ ExportDoc found ] declWith :: HsQName -> ErrMsgM [ ExportItem ] declWith (UnQual _) = return [] declWith t@(Qual mdl x) | Just decl <- findDecl t = return [ ExportDecl t (restrictTo subs (extractDecl x mdl decl)) [] ] | otherwise = return [ ExportNoDecl t t (map (Qual mdl) subs) ] -- can't find the decl (it might be from another package), but let's -- list the entity anyway. Later on, the renamer will change the -- orig name into the import name, so we get a proper link to -- the doc for this entity. where subs = map nameOfQName subs_qnames subs_qnames = filter (`elem` exported_names) all_subs_qnames all_subs_qnames = map (Qual mdl) all_subs all_subs | mdl == this_mod = Map.findWithDefault [] x sub_map | otherwise = all_subs_of_qname mod_map t fullContentsOf m | m == this_mod = return (fullContentsOfThisModule this_mod decls) | otherwise = case Map.lookup m mod_map of Just iface | OptHide `elem` iface_options iface -> return (iface_orig_exports iface) | otherwise -> return [ ExportModule m ] Nothing -> return [] -- already emitted a warning in exportedNames findDecl :: HsQName -> Maybe HsDecl findDecl (UnQual _) = Nothing -- must be a name we couldn't resolve findDecl (Qual m n) | m == this_mod = Map.lookup n decl_map | otherwise = case Map.lookup m mod_map of Just iface -> Map.lookup n (iface_decls iface) Nothing -> Nothing fullContentsOfThisModule :: Module -> [HsDecl] -> [ExportItem] fullContentsOfThisModule mdl decls = map mkExportItem (filter keepDecl decls) where mkExportItem (HsDocGroup _ lev doc) = ExportGroup lev "" doc mkExportItem decl = ExportDecl (Qual mdl x) decl [] where Just x = declMainBinder decl keepDecl :: HsDecl -> Bool keepDecl HsTypeSig{} = True keepDecl HsTypeDecl{} = True keepDecl HsNewTypeDecl{} = True keepDecl HsDataDecl{} = True keepDecl HsClassDecl{} = True keepDecl HsDocGroup{} = True keepDecl HsForeignImport{} = True keepDecl _ = False -- 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 :: HsName -> Module -> HsDecl -> HsDecl extractDecl name mdl decl | Just n <- declMainBinder decl, n == name = decl | otherwise = case decl of HsClassDecl _ _ n tvs _ decls _ -> case [ d | d@HsTypeSig{} <- decls, declMainBinder d == Just name ] of [d0] -> extractClassDecl n mdl tvs d0 _ -> error "internal: extractDecl" HsDataDecl _ _ t tvs cons _ _ -> extractRecSel name mdl t tvs cons HsNewTypeDecl _ _ t tvs con _ _ -> extractRecSel name mdl t tvs [con] _ -> error ("extractDecl: " ++ show decl) extractClassDecl :: HsName -> Module -> [HsName] -> HsDecl -> HsDecl extractClassDecl c mdl tvs0 (HsTypeSig loc [n] ty doc) = case ty of HsForAllType tvs ctxt' ty' -> HsTypeSig loc [n] (HsForAllType tvs (ctxt ++ ctxt') ty') doc _ -> HsTypeSig loc [n] (HsForAllType Nothing ctxt ty) doc where ctxt = [HsAssump (Qual mdl c, map HsTyVar tvs0)] extractClassDecl _ _ _ d = error $ "Main.extractClassDecl: unexpected decl: " ++ show d extractRecSel :: HsName -> Module -> HsName -> [HsName] -> [HsConDecl] -> HsDecl extractRecSel _ _ _ _ [] = error "extractRecSel: selector not found" extractRecSel nm mdl t tvs (d@(HsConDecl{}):rest) = extractRecSel nm mdl t tvs rest extractRecSel nm mdl t tvs (HsRecDecl loc _ _tvs _ fields _mb_doc : rest) | (HsFieldDecl ns ty mb_doc : _) <- matching_fields = HsTypeSig loc [nm] (HsTyFun data_ty (unbang ty)) mb_doc | otherwise = extractRecSel nm mdl t tvs rest where matching_fields = [ f | f@(HsFieldDecl ns ty mb_doc) <- fields, nm `elem` ns ] data_ty = foldl HsTyApp (HsTyCon (Qual mdl t)) (map HsTyVar tvs) -- ----------------------------------------------------------------------------- -- Pruning pruneExportItems :: [ExportItem] -> [ExportItem] pruneExportItems items = filter has_doc items where has_doc (ExportDecl _ d _) = isJust (declDoc d) has_doc _ = True -- ----------------------------------------------------------------------------- -- Make a sub-name map for this module mkSubNames :: [HsDecl] -> Map HsName [HsName] mkSubNames decls = Map.fromList [ (n, subs) | d <- decls, Just n <- [declMainBinder d], subs@(_:_) <- [declSubBinders d] ] -- ----------------------------------------------------------------------------- -- Gather a list of original names exported from this module exportedNames :: Module -> ModuleMap -> [HsName] -> Map HsQName HsQName -> Map HsName [HsName] -> Maybe [HsExportSpec] -> [DocOption] -> ErrMsgM ([HsQName], [HsQName]) exportedNames mdl mod_map local_names orig_env sub_map maybe_exps opts | Nothing <- maybe_exps = return all_local_names_pr | OptIgnoreExports `elem` opts = return all_local_names_pr | Just expspecs <- maybe_exps = do all_names <- mapM extract expspecs all_vis_names <- mapM extract_vis expspecs return (concat all_names, concat all_vis_names) where all_local_names = map (Qual mdl) local_names all_local_names_pr = (all_local_names,all_local_names) in_scope = Set.fromList (Map.elems orig_env) extract e = case e of HsEVar x -> return [x] HsEAbs t -> return [t] HsEThingAll t@(Qual m x) -> return (t : filter (`Set.member` in_scope) (map (Qual m) all_subs)) where all_subs | m == mdl = Map.findWithDefault [] x sub_map | otherwise = all_subs_of_qname mod_map t HsEThingWith t cs -> return (t : cs) HsEModuleContents m | m == mdl -> return (map (Qual mdl) local_names) | otherwise -> case Map.lookup m mod_map of Just iface -> return (filter (`Set.member` in_scope) (Map.elems (iface_env iface))) Nothing -> do tell (exportModuleMissingErr mdl m) return [] _ -> return [] -- Just the names that will be visible in the documentation -- (ie. omit names exported via a 'module M' export, if we are just -- going to cross-reference the module). extract_vis e = case e of HsEModuleContents m | m == mdl -> return (map (Qual mdl) local_names) | otherwise -> case Map.lookup m mod_map of Just iface | OptHide `elem` iface_options iface -> return (filter (`Set.member` in_scope) (Map.elems (iface_env iface))) | otherwise -> return [] Nothing -> return [] -- we already emitted a warning above -- remaining cases: we have to catch names which are reexported from -- here, but for which we have no documentation, perhaps because they -- are from another package. We have to do this by looking for -- the declaration in the other module. _ -> do xs <- extract e return (filter is_documented_here xs) is_documented_here (UnQual _) = False is_documented_here (Qual m n) | m == mdl = True -- well, it's not documented anywhere else! | otherwise = case Map.lookup m mod_map of Nothing -> False Just iface -> isJust (Map.lookup n (iface_decls iface)) exportModuleMissingErr this mdl = ["Warning: in export list of " ++ show this ++ ": module not found: " ++ show mdl] -- for a given entity, find all the names it "owns" (ie. all the -- constructors and field names of a tycon, or all the methods of a -- class). all_subs_of_qname :: ModuleMap -> HsQName -> [HsName] all_subs_of_qname mod_map (Qual mdl nm) = case Map.lookup mdl mod_map of Just iface -> Map.findWithDefault [] nm (iface_sub iface) Nothing -> [] all_subs_of_qname _ n@(UnQual _) = error $ "Main.all_subs_of_qname: unexpected unqual'd name:" ++ show n -- ---------------------------------------------------------------------------- -- Building name environments -- The orig env maps names in the current source file to -- fully-qualified "original" names. buildOrigEnv :: Module -> Bool -> ModuleMap -> [HsImportDecl] -> ErrMsgM (Map HsQName HsQName) buildOrigEnv this_mdl verbose mod_map imp_decls = do maps <- mapM build imp_decls return (Map.unions (reverse maps)) where build imp_decl@(HsImportDecl _ mdl qual maybe_as _) = case Map.lookup mdl mod_map of Nothing -> do when verbose $ -- only emit missing module messages when -v is on. Otherwise -- we get a ton of spurious messages about missing "Prelude". tell ["Warning: " ++ show this_mdl ++ ": imported module not found: " ++ show mdl] return Map.empty Just iface -> return (Map.fromList (concat (map orig_map (processImportDecl mod_map imp_decl)))) where -- bring both qualified and unqualified names into scope, unless -- the import was 'qualified'. orig_map (nm,qnm) | qual = [ (Qual qual_module nm, qnm) ] | otherwise = [ (Qual qual_module nm, qnm), (UnQual nm, qnm) ] qual_module | Just m <- maybe_as = m | otherwise = mdl processImportDecl :: ModuleMap -> HsImportDecl -> [(HsName,HsQName)] processImportDecl mod_map (HsImportDecl _ mdl is_qualified maybe_as imp_specs) = case Map.lookup mdl mod_map of Nothing -> [] Just iface -> imported_names where env = iface_env iface sub = iface_sub iface all_names = Map.toAscList env imported_names :: [(HsName,HsQName)] imported_names = case imp_specs of Nothing -> all_names Just (False,specs) -> [ (n,qnm) | (n,qnm) <- all_names, n `elem` names specs False ] Just (True, specs) -> [ (n,qnm) | (n,qnm) <- all_names, n `notElem` names specs True ] where names specs is_hiding = concat (map (spec_names is_hiding) specs) -- when hiding, a conid refers to both the constructor and -- the type/class constructor. spec_names _hid (HsIVar v) = [v] spec_names True (HsIAbs (HsTyClsName i)) = [HsTyClsName i, HsVarName i] spec_names False (HsIAbs v) = [v] spec_names _hid (HsIThingAll v) = v : sub_names v spec_names _hid (HsIThingWith v xs) = v : xs sub_names :: HsName -> [HsName] sub_names nm = case Map.lookup nm env of Just qnm -> filter (`Map.member` env) (all_subs_of_qname mod_map qnm) _ -> [] -- ----------------------------------------------------------------------------- -- | Build a mapping which for each original name, points to the "best" -- place to link to in the documentation. For the definition of -- "best", we use "the module nearest the bottom of the dependency -- graph which exports this name", not including hidden modules. When -- there are multiple choices, we pick a random one. -- -- The interfaces are passed in in topologically sorted order, but we start -- by reversing the list so we can do a foldl. -- buildGlobalDocEnv :: [Interface] -> Map HsQName HsQName buildGlobalDocEnv ifaces = foldl upd Map.empty (reverse ifaces) where upd old_env iface | OptHide `elem` iface_options iface = old_env | OptNotHome `elem` iface_options iface = foldl' keep_old old_env exported_names | otherwise = foldl' keep_new old_env exported_names where mdl = iface_module iface exported_names = filter not_reexported (Map.elems (iface_env iface)) not_reexported (Qual _ n) = n `notElem` iface_reexported iface not_reexported (UnQual n) = n `notElem` iface_reexported iface -- UnQual probably shouldn't happen keep_old env qnm = Map.insertWith (\new old -> old) qnm (Qual mdl nm) env where nm = nameOfQName qnm keep_new env qnm = Map.insert qnm (Qual mdl nm) env where nm = nameOfQName qnm builtinDocEnv = Map.fromList (map (\a -> (a,a)) builtinNames) -- These names cannot be explicitly exported, so we need to treat -- them specially. builtinNames = [unit_tycon_qname, fun_tycon_qname, list_tycon_qname, unit_con_name, nil_con_name] -- ----------------------------------------------------------------------------- -- Expand multiple type signatures expandDecl :: HsDecl -> [HsDecl] expandDecl (HsTypeSig loc fs qt doc) = [ HsTypeSig loc [f] qt doc | f <- fs ] expandDecl (HsClassDecl loc ctxt n tvs fds decls doc) = [ HsClassDecl loc ctxt n tvs fds (concat (map expandDecl decls)) doc ] expandDecl d = [ d ] ----------------------------------------------------------------------------- -- Collecting documentation and attach it to the right declarations collectDoc :: [HsDecl] -> [HsDecl] collectDoc decls = collect Nothing DocEmpty decls collect :: Maybe HsDecl -> GenDoc [HsQName] -> [HsDecl] -> [HsDecl] collect d doc_so_far [] = case d of Nothing -> [] Just d0 -> finishedDoc d0 doc_so_far [] collect d doc_so_far (decl:ds) = case decl of HsDocCommentNext _ str -> case d of Nothing -> collect d (docAppend doc_so_far str) ds Just d0 -> finishedDoc d0 doc_so_far (collect Nothing str ds) HsDocCommentPrev _ str -> collect d (docAppend doc_so_far str) ds _other -> let decl' = collectInDecl decl in case d of Nothing -> collect (Just decl') doc_so_far ds Just d0 -> finishedDoc d0 doc_so_far (collect (Just decl') DocEmpty ds) finishedDoc :: HsDecl -> GenDoc [HsQName] -> [HsDecl] -> [HsDecl] finishedDoc d DocEmpty rest = d : rest finishedDoc d doc rest = d' : rest where d' = case d of HsTypeDecl loc n ns ty _ -> HsTypeDecl loc n ns ty (Just doc) HsDataDecl loc ctxt n ns cons drv _ -> HsDataDecl loc ctxt n ns cons drv (Just doc) HsNewTypeDecl loc ctxt n ns con drv _ -> HsNewTypeDecl loc ctxt n ns con drv (Just doc) HsClassDecl loc ctxt n tvs fds meths _ -> HsClassDecl loc ctxt n tvs fds meths (Just doc) HsTypeSig loc ns ty _ -> HsTypeSig loc ns ty (Just doc) HsForeignImport loc cc sf str n ty _ -> HsForeignImport loc cc sf str n ty (Just doc) _other -> d collectInDecl :: HsDecl -> HsDecl collectInDecl (HsClassDecl loc ctxt n tvs fds meths doc) = HsClassDecl loc ctxt n tvs fds (collect Nothing DocEmpty meths) doc collectInDecl decl = decl -- ----------------------------------------------------------------------------- -- Named documentation findNamedDoc :: String -> [HsDecl] -> ErrMsgM (Maybe Doc) findNamedDoc name decls = search decls where search [] = do tell ["Cannot find documentation for: $" ++ name] return Nothing search (HsDocCommentNamed _ name' doc : rest) | name == name' = return (Just doc) | otherwise = search rest search (_other_decl : rest) = search rest -- ----------------------------------------------------------------------------- -- Haddock options embedded in the source file processOptions :: String -> ErrMsgM [DocOption] processOptions str = do case break (== ',') str of (this, ',':rest) -> do opt <- parseOption this opts <- processOptions rest return (maybeToList opt ++ opts) (this, _) | all isSpace this -> return [] | otherwise -> do opt <- parseOption this; return (maybeToList opt) 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 = do tell ["Unrecognised option: " ++ other]; return Nothing -- ----------------------------------------------------------------------------- -- Topologically sort the modules sortModules :: [(HsModule,FilePath)] -> IO [(HsModule,FilePath)] sortModules mdls = mapM for_each_scc sccs where sccs = stronglyConnComp edges edges :: [((HsModule,FilePath), Module, [Module])] edges = [ ((hsmod,file), mdl, get_imps impdecls) | (hsmod@(HsModule _ mdl _ impdecls _ _ _ _), file) <- mdls ] get_imps impdecls = [ imp | HsImportDecl _ imp _ _ _ <- impdecls ] get_mods hsmodules = [ mdl | HsModule _ mdl _ _ _ _ _ _ <- hsmodules ] for_each_scc (AcyclicSCC hsmodule) = return hsmodule for_each_scc (CyclicSCC hsmodules) = dieMsg ("modules are recursive: " ++ unwords (map show (get_mods (map fst hsmodules)))) -- ----------------------------------------------------------------------------- -- Collect instances and attach them to declarations attachInstances :: [Interface] -> [Interface] attachInstances mod_ifaces = map attach mod_ifaces where inst_map = fmap (sortImage instHead) $ collectInstances mod_ifaces attach iface = iface{ iface_orig_exports = new_exports } where new_exports = map attach_export (iface_orig_exports iface) attach_export (ExportDecl nm decl _) = ExportDecl nm decl (case Map.lookup nm inst_map of Nothing -> [] Just instheads -> instheads) attach_export other_export = other_export collectInstances :: [Interface] -> Map HsQName [InstHead] -- maps class/type names to instances collectInstances ifaces = Map.fromListWith (flip (++)) ty_inst_pairs `Map.union` Map.fromListWith (flip (++)) class_inst_pairs where all_instances = concat (map iface_insts ifaces) class_inst_pairs = [ (cls, [(ctxt,(cls,args))]) | HsInstDecl _ ctxt (cls,args) _ <- all_instances ] ty_inst_pairs = [ (nm, [(ctxt,(cls,args))]) | HsInstDecl _ ctxt (cls,args) _ <- all_instances, nm <- nub (concat (map freeTyCons args)) ] -- simplified type for sorting types, ignoring qualification (not visible -- in Haddock output) and unifying special tycons with normal ones. data SimpleType = SimpleType HsName [SimpleType] deriving (Eq,Ord) -- Sort key for instances: -- arities of arguments, to place higher-kind instances -- name of class -- type arguments instHead :: (HsContext,(HsQName,[HsType])) -> ([Int],HsName,[SimpleType]) instHead (ctxt,(cls,args)) = (map argCount args, nameOfQName cls, map simplify args) where argCount (HsTyApp t _) = argCount t + 1 argCount _ = 0 simplify (HsForAllType tvs ctxt t) = simplify t simplify (HsTyFun t1 t2) = SimpleType fun_tycon_name [simplify t1, simplify t2] simplify (HsTyTuple b ts) = SimpleType (tuple_tycon_name (length ts - 1)) (map simplify ts) simplify (HsTyApp t1 t2) = SimpleType s (args ++ [simplify t2]) where (SimpleType s args) = simplify t1 simplify (HsTyVar v) = SimpleType v [] simplify (HsTyCon n) = SimpleType (nameOfQName n) [] simplify (HsTyDoc t _) = simplify t simplify (HsTyIP n t) = simplify t -- sortImage f = sortBy (\x y -> compare (f x) (f y)) sortImage :: Ord b => (a -> b) -> [a] -> [a] sortImage f xs = map snd $ sortBy cmp_fst [(f x, x) | x <- xs] where cmp_fst (x,_) (y,_) = compare x y -- ----------------------------------------------------------------------------- -- The interface file format. -- This has to read interfaces up to Haddock 0.6 (without the short -- document annotations), and interfaces afterwards, so we use the -- FormatVersion hack to work out which one the interface file contains. thisFormatVersion :: FormatVersion thisFormatVersion = mkFormatVersion 2 -- | How we store interfaces. Not everything is stored. type StoredInterface2 = (Module,Maybe Doc,Maybe String,Bool,[(HsName,Module)], [(HsName,[HsName])]) -- | How we store interfaces. Not everything is stored. type StoredInterface1 = (Module,Maybe Doc,Maybe String,Bool,[(HsName,HsQName)],[(HsName,HsQName)], [(HsName,[HsName])]) -- | How we used to store interfaces. type NullVersionStoredInterface = (Module,Maybe String,Bool,[(HsName,HsQName)],[(HsName,HsQName)], [(HsName,[HsName])]) dumpInterfaces :: [Interface] -> Map HsQName HsQName -> FilePath -> IO () dumpInterfaces interfaces global_doc_env fileName = do let preparedInterfaces :: [StoredInterface2] preparedInterfaces = map from_interface interfaces bh <- openBinMem 100000 put_ bh thisFormatVersion put_ bh preparedInterfaces putDocEnv bh global_doc_env writeBinMem bh fileName readIface :: FilePath -> IO ([Interface], Map HsQName HsQName) readIface fileName = do bh <- readBinMem fileName formatVersion <- get bh case formatVersion of v | v == thisFormatVersion -> do (stuff :: [StoredInterface2]) <- get bh doc_env <- getDocEnv bh return (map to_interface2 stuff, doc_env) v | v == mkFormatVersion 1 -> do (stuff :: [StoredInterface1]) <- get bh return (map to_interface1 stuff, Map.empty) v | v == nullFormatVersion -> do (stuff :: [NullVersionStoredInterface]) <- get bh return (map nullVersion_to_interface stuff, Map.empty) otherwise -> do noDieMsg ( "Warning: The interface file " ++ show fileName ++ " could not be read.\n" ++ "Maybe it's from a later version of Haddock?\n") return ([], Map.empty) from_interface :: Interface -> StoredInterface2 from_interface iface = ( iface_module iface, toDescription iface,iface_package iface, OptHide `elem` iface_options iface, [(n,mdl) | (n,Qual mdl n') <- Map.toAscList (iface_env iface), if n /= n' then error "help!" else True], Map.toAscList (iface_sub iface) ) getDocEnv :: BinHandle -> IO (Map HsQName HsQName) getDocEnv bh = do doc_env_list <- get bh return (Map.fromList [(Qual mdl1 nm,Qual mdl2 nm) | (mdl1,nm,mdl2) <- doc_env_list]) putDocEnv :: BinHandle -> Map HsQName HsQName -> IO () putDocEnv bh env = do let doc_env_list = [(mdl1,nm,mdl2) | (Qual mdl1 nm, Qual mdl2 _) <- Map.toAscList env] put_ bh doc_env_list to_interface1 :: StoredInterface1 -> Interface to_interface1 (mdl,descriptionOpt,package, hide, env, _, sub) = Interface { iface_module = mdl, iface_filename = "", iface_orig_filename= "", iface_package = package, iface_env = Map.fromList env, iface_sub = Map.fromList sub, iface_reexported = [], iface_exports = [], iface_orig_exports = [], iface_insts = [], iface_decls = Map.empty, iface_info = toModuleInfo descriptionOpt, iface_doc = Nothing, iface_options = if hide then [OptHide] else [] } to_interface2 :: StoredInterface2 -> Interface to_interface2 (mdl,descriptionOpt,package, hide, env, sub) = Interface { iface_module = mdl, iface_filename = "", iface_orig_filename= "", iface_package = package, iface_env = Map.fromList [(n,Qual mdl n) | (n,mdl) <- env], iface_sub = Map.fromList sub, iface_reexported = [], iface_exports = [], iface_orig_exports = [], iface_insts = [], iface_decls = Map.empty, iface_info = toModuleInfo descriptionOpt, iface_doc = Nothing, iface_options = if hide then [OptHide] else [] } nullVersion_to_interface :: NullVersionStoredInterface -> Interface nullVersion_to_interface (mdl, package, hide, env, reexported, sub) = Interface { iface_module = mdl, iface_filename = "", iface_orig_filename= "", iface_package = package, iface_env = Map.fromList env, iface_sub = Map.fromList sub, iface_reexported = [], iface_exports = [], iface_orig_exports = [], iface_insts = [], iface_decls = Map.empty, iface_info = emptyModuleInfo, iface_doc = Nothing, iface_options = if hide then [OptHide] else [] } toModuleInfo :: Maybe Doc -> ModuleInfo toModuleInfo descriptionOpt = emptyModuleInfo {description = descriptionOpt} -- ----------------------------------------------------------------------------- -- A monad which collects error messages type ErrMsg = String type ErrMsgM a = Writer [ErrMsg] a