Per-module extension flags and language listing.

Any extensions that are not enabled by a used language (Haskell2010
&c) will be shown. Furthermore, any implicitly enabled are also going
to be shown. While we could eliminate this either by using the GHC API
or a dirty hack, I opted not to: if a user doesn't want the implied
flags to show, they are recommended to use enable extensions more
carefully or individually. Perhaps this will encourage users to not
enable the most powerful flags needlessly. Enabled with show-extensions.

Conflicts:
	src/Haddock/InterfaceFile.hs

8 files changed, 89 insertions, 36 deletions

diff --git a/src/Haddock/Backends/LaTeX.hs b/src/Haddock/Backends/LaTeX.hs
index 5f00d784..4a30a168 100644
--- a/src/Haddock/Backends/LaTeX.hs
+++ b/src/Haddock/Backends/LaTeX.hs
@@ -2,7 +2,8 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Haddock.Backends.LaTeX
--- Copyright   :  (c) Simon Marlow 2010
+-- Copyright   :  (c) Simon Marlow      2010,
+--                    Mateusz Kowalczyk 2013
 -- License     :  BSD-like
 --
 -- Maintainer  :  haddock@projects.haskell.org
diff --git a/src/Haddock/Backends/Xhtml.hs b/src/Haddock/Backends/Xhtml.hs
index 96aea5e5..1b6d7fe5 100644
--- a/src/Haddock/Backends/Xhtml.hs
+++ b/src/Haddock/Backends/Xhtml.hs
@@ -1,9 +1,10 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Haddock.Backends.Html
--- Copyright   :  (c) Simon Marlow   2003-2006,
---                    David Waern    2006-2009,
---                    Mark Lentczner 2010
+-- Copyright   :  (c) Simon Marlow      2003-2006,
+--                    David Waern       2006-2009,
+--                    Mark Lentczner    2010,
+--                    Mateusz Kowalczyk 2013
 -- License     :  BSD-like
 --
 -- Maintainer  :  haddock@projects.haskell.org
@@ -38,7 +39,8 @@ import Control.Monad         ( when, unless )
 import Control.Monad.Instances ( ) -- for Functor Either a
 #endif
 import Data.Char             ( toUpper )
-import Data.List             ( sortBy, groupBy, intercalate )
+import Data.Functor          ( (<$>) )
+import Data.List             ( sortBy, groupBy, intercalate, isPrefixOf )
 import Data.Maybe
 import System.FilePath hiding ( (</>) )
 import System.Directory
@@ -48,11 +50,11 @@ import qualified Data.Set as Set hiding ( Set )
 import Data.Function
 import Data.Ord              ( comparing )
 
+import DynFlags (Language(..))
 import GHC hiding ( NoLink, moduleInfo )
 import Name
 import Module
 
-
 --------------------------------------------------------------------------------
 -- * Generating HTML documentation
 --------------------------------------------------------------------------------
@@ -174,7 +176,7 @@ bodyHtml doctitle iface
     divPackageHeader << [
       unordList (catMaybes [
         srcButton maybe_source_url iface,
-        wikiButton maybe_wiki_url (ifaceMod `fmap` iface),
+        wikiButton maybe_wiki_url (ifaceMod <$> iface),
         contentsButton maybe_contents_url,
         indexButton maybe_index_url])
             ! [theclass "links", identifier "page-menu"],
@@ -205,8 +207,26 @@ moduleInfo iface =
           ("Maintainer",hmi_maintainer),
           ("Stability",hmi_stability),
           ("Portability",hmi_portability),
-          ("Safe Haskell",hmi_safety)
-          ]
+          ("Safe Haskell",hmi_safety),
+          ("Language", lg)
+          ] ++ extsForm
+        where
+          lg inf = case hmi_language inf of
+            Nothing -> Nothing
+            Just Haskell98 -> Just "Haskell98"
+            Just Haskell2010 -> Just "Haskell2010"
+
+          extsForm
+            | OptShowExtensions `elem` ifaceOptions iface =
+              let fs = map (dropOpt . show) (hmi_extensions info)
+              in case map stringToHtml fs of
+                [] -> []
+                [x] -> extField x -- don't use a list for a single extension
+                xs -> extField $ unordList xs ! [theclass "extension-list"]
+            | otherwise = []
+            where
+              extField x = return $ th << "Extensions" <-> td << x
+              dropOpt x = if "Opt_" `isPrefixOf` x then drop 4 x else x
    in
       case entries of
          [] -> noHtml
@@ -283,7 +303,7 @@ mkNode qual ss p (Node s leaf pkg short ts) =
       -- We only need an explicit collapser button when the module name
       -- is also a leaf, and so is a link to a module page. Indeed, the
       -- spaceHtml is a minor hack and does upset the layout a fraction.
-      
+
     htmlModule = thespan ! modAttrs << (cBtn +++
       if leaf
         then ppModule (mkModule (stringToPackageId (fromMaybe "" pkg))
@@ -529,7 +549,7 @@ ifaceToHtml maybe_source_url maybe_wiki_url iface unicode qual
       | no_doc_at_all = noHtml
       | otherwise
       = divSynposis $
-            paragraph ! collapseControl "syn" False "caption" << "Synopsis" +++ 
+            paragraph ! collapseControl "syn" False "caption" << "Synopsis" +++
             shortDeclList (
                 mapMaybe (processExport True linksInfo unicode qual) exports
             ) ! (collapseSection "syn" False "" ++ collapseToggle "syn")
@@ -559,7 +579,7 @@ miniSynopsis mdl iface unicode qual =
 processForMiniSynopsis :: Module -> Bool -> Qualification -> ExportItem DocName
                        -> [Html]
 processForMiniSynopsis mdl unicode qual (ExportDecl (L _loc decl0) _doc _ _insts) =
-  ((divTopDecl <<).(declElem <<)) `fmap` case decl0 of
+  ((divTopDecl <<).(declElem <<)) <$> case decl0 of
     TyClD d -> let b = ppTyClBinderWithVarsMini mdl d in case d of
         (FamDecl decl)    -> [ppTyFamHeader True False decl unicode qual]
         (DataDecl{})   -> [keyword "data" <+> b]
@@ -666,5 +686,3 @@ groupTag lev
   | lev == 2  = h2
   | lev == 3  = h3
   | otherwise = h4
-
-
diff --git a/src/Haddock/Interface/Create.hs b/src/Haddock/Interface/Create.hs
index 825e9624..6c20f00b 100644
--- a/src/Haddock/Interface/Create.hs
+++ b/src/Haddock/Interface/Create.hs
@@ -3,8 +3,9 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Haddock.Interface.Create
--- Copyright   :  (c) Simon Marlow 2003-2006,
---                    David Waern  2006-2009
+-- Copyright   :  (c) Simon Marlow      2003-2006,
+--                    David Waern       2006-2009,
+--                    Mateusz Kowalczyk 2013
 -- License     :  BSD-like
 --
 -- Maintainer  :  haddock@projects.haskell.org
@@ -218,16 +219,20 @@ mkDocOpts mbOpts flags mdl = do
       [] -> 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
+  hm <- if Flag_HideModule (moduleString mdl) `elem` flags
+        then return $ OptHide : opts
+        else return opts
+  if Flag_ShowExtensions (moduleString mdl) `elem` flags
+    then return $ OptShowExtensions : hm
+    else return hm
 
 
 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 "hide"            = return (Just OptHide)
+parseOption "prune"           = return (Just OptPrune)
+parseOption "ignore-exports"  = return (Just OptIgnoreExports)
+parseOption "not-home"        = return (Just OptNotHome)
+parseOption "show-extensions" = return (Just OptShowExtensions)
 parseOption other = tell ["Unrecognised option: " ++ other] >> return Nothing
 
 
@@ -649,7 +654,7 @@ lookupDocs n warnings docMap argMap subMap =
 -- 2) B is visible, but not all its exports are in scope in A, in which case we
 --    only return those that are.
 -- 3) B is visible and all its exports are in scope, in which case we return
---    a single 'ExportModule' item. 
+--    a single 'ExportModule' item.
 moduleExports :: Module           -- ^ Module A
               -> ModuleName       -- ^ The real name of B, the exported module
               -> DynFlags         -- ^ The flags used when typechecking A
diff --git a/src/Haddock/Interface/LexParseRn.hs b/src/Haddock/Interface/LexParseRn.hs
index 73f2c165..c302e4f0 100644
--- a/src/Haddock/Interface/LexParseRn.hs
+++ b/src/Haddock/Interface/LexParseRn.hs
@@ -4,6 +4,7 @@
 -- |
 -- Module      :  Haddock.Interface.LexParseRn
 -- Copyright   :  (c) Isaac Dupree 2009,
+--                    Mateusz Kowalczyk 2013
 -- License     :  BSD-like
 --
 -- Maintainer  :  haddock@projects.haskell.org
@@ -17,7 +18,7 @@ module Haddock.Interface.LexParseRn
   , processModuleHeader
   ) where
 
-
+import qualified Data.IntSet as IS
 import Haddock.Types
 import Haddock.Parser
 import Haddock.Interface.ParseModuleHeader
@@ -28,11 +29,11 @@ import Data.List
 import Data.Maybe
 import FastString
 import GHC
+import DynFlags (ExtensionFlag(..), languageExtensions)
 import Name
 import Outputable
 import RdrName
 
-
 processDocStrings :: DynFlags -> GlobalRdrEnv -> [HsDocString] -> ErrMsgM (Maybe (Doc Name))
 processDocStrings dflags gre strs = do
   docs <- catMaybes <$> mapM (processDocStringParas dflags gre) strs
@@ -82,7 +83,14 @@ processModuleHeader dflags gre safety mayStr = do
                 hmi' = hmi { hmi_description = descr }
                 doc' = rename dflags gre doc
             return (hmi', Just doc')
-  return (hmi { hmi_safety = Just $ showPpr dflags safety }, doc)
+
+  let flags :: [ExtensionFlag]
+      -- We remove the flags implied by the language setting and we display the language instead
+      flags = map toEnum (IS.toList $ extensionFlags dflags) \\ languageExtensions (language dflags)
+  return (hmi { hmi_safety = Just $ showPpr dflags safety
+              , hmi_language = language dflags
+              , hmi_extensions = flags
+              } , doc)
   where
     failure = (emptyHaddockModInfo, Nothing)
 
diff --git a/src/Haddock/Interface/ParseModuleHeader.hs b/src/Haddock/Interface/ParseModuleHeader.hs
index ade28728..0be2511f 100644
--- a/src/Haddock/Interface/ParseModuleHeader.hs
+++ b/src/Haddock/Interface/ParseModuleHeader.hs
@@ -61,7 +61,9 @@ parseModuleHeader dflags str0 =
             hmi_maintainer = maintainerOpt,
             hmi_stability = stabilityOpt,
             hmi_portability = portabilityOpt,
-            hmi_safety = Nothing
+            hmi_safety = Nothing,
+            hmi_language = Nothing, -- set in LexParseRn
+            hmi_extensions = [] -- also set in LexParseRn
             }, doc)
 
 -- | This function is how we read keys.
@@ -158,4 +160,3 @@ parseKey key toParse0 =
       extractPrefix (c1:cs1) (c2:cs2)
          | toUpper c1 == toUpper c2 = extractPrefix cs1 cs2
          | otherwise = Nothing
-
diff --git a/src/Haddock/InterfaceFile.hs b/src/Haddock/InterfaceFile.hs
index 6bf22c9b..81ff17fd 100644
--- a/src/Haddock/InterfaceFile.hs
+++ b/src/Haddock/InterfaceFile.hs
@@ -3,7 +3,8 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Haddock.InterfaceFile
--- Copyright   :  (c) David Waern 2006-2009
+-- Copyright   :  (c) David Waern       2006-2009,
+--                    Mateusz Kowalczyk 2013
 -- License     :  BSD-like
 --
 -- Maintainer  :  haddock@projects.haskell.org
@@ -24,6 +25,7 @@ import Haddock.Utils hiding (out)
 
 import Control.Monad
 import Data.Array
+import Data.Functor ((<$>))
 import Data.IORef
 import Data.List
 import qualified Data.Map as Map
@@ -396,6 +398,8 @@ instance Binary DocOption where
             putByte bh 2
     put_ bh OptNotHome = do
             putByte bh 3
+    put_ bh OptShowExtensions = do
+            putByte bh 4
     get bh = do
             h <- getByte bh
             case h of
@@ -407,6 +411,8 @@ instance Binary DocOption where
                     return OptIgnoreExports
               3 -> do
                     return OptNotHome
+              4 -> do
+                    return OptShowExtensions
               _ -> fail "invalid binary data found"
 
 
@@ -590,6 +596,8 @@ instance Binary name => Binary (HaddockModInfo name) where
     put_ bh (hmi_stability   hmi)
     put_ bh (hmi_portability hmi)
     put_ bh (hmi_safety      hmi)
+    put_ bh (fromEnum <$> hmi_language hmi)
+    put_ bh (map fromEnum $ hmi_extensions hmi)
 
   get bh = do
     descr <- get bh
@@ -599,8 +607,9 @@ instance Binary name => Binary (HaddockModInfo name) where
     stabi <- get bh
     porta <- get bh
     safet <- get bh
-    return (HaddockModInfo descr copyr licen maint stabi porta safet)
-
+    langu <- fmap toEnum <$> get bh
+    exten <- map toEnum <$> get bh
+    return (HaddockModInfo descr copyr licen maint stabi porta safet langu exten)
 
 instance Binary DocName where
   put_ bh (Documented name modu) = do
diff --git a/src/Haddock/Options.hs b/src/Haddock/Options.hs
index 751812d4..12c80b6e 100644
--- a/src/Haddock/Options.hs
+++ b/src/Haddock/Options.hs
@@ -1,8 +1,9 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Haddock.Options
--- Copyright   :  (c) Simon Marlow 2003-2006,
---                    David Waern  2006-2009
+-- Copyright   :  (c) Simon Marlow      2003-2006,
+--                    David Waern       2006-2009,
+--                    Mateusz Kowalczyk 2013
 -- License     :  BSD-like
 --
 -- Maintainer  :  haddock@projects.haskell.org
@@ -70,6 +71,7 @@ data Flag
   | Flag_GenIndex
   | Flag_IgnoreAllExports
   | Flag_HideModule String
+  | Flag_ShowExtensions String
   | Flag_OptGhc String
   | Flag_GhcLibDir String
   | Flag_GhcVersion
@@ -151,6 +153,8 @@ options backwardsCompat =
       "behave as if all modules have the\nignore-exports atribute",
     Option [] ["hide"] (ReqArg Flag_HideModule "MODULE")
       "behave as if MODULE has the hide attribute",
+    Option [] ["show-extensions"] (ReqArg Flag_ShowExtensions "MODULE")
+      "behave as if MODULE has the show-extensions attribute",
     Option [] ["optghc"] (ReqArg Flag_OptGhc "OPTION")
       "option to be forwarded to GHC",
     Option []  ["ghc-version"]  (NoArg Flag_GhcVersion)
diff --git a/src/Haddock/Types.hs b/src/Haddock/Types.hs
index 27a6201f..f90e5496 100644
--- a/src/Haddock/Types.hs
+++ b/src/Haddock/Types.hs
@@ -3,8 +3,9 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Haddock.Types
--- Copyright   :  (c) Simon Marlow 2003-2006,
---                    David Waern  2006-2009
+-- Copyright   :  (c) Simon Marlow      2003-2006,
+--                    David Waern       2006-2009,
+--                    Mateusz Kowalczyk 2013
 -- License     :  BSD-like
 --
 -- Maintainer  :  haddock@projects.haskellorg
@@ -28,6 +29,7 @@ import Data.Typeable
 import Data.Map (Map)
 import qualified Data.Map as Map
 import GHC hiding (NoLink)
+import DynFlags (ExtensionFlag, Language)
 import OccName
 import Control.Applicative (Applicative(..))
 import Control.Monad (ap)
@@ -422,6 +424,8 @@ data HaddockModInfo name = HaddockModInfo
   , hmi_stability   :: Maybe String
   , hmi_portability :: Maybe String
   , hmi_safety      :: Maybe String
+  , hmi_language    :: Maybe Language
+  , hmi_extensions  :: [ExtensionFlag]
   }
 
 
@@ -434,6 +438,8 @@ emptyHaddockModInfo = HaddockModInfo
   , hmi_stability   = Nothing
   , hmi_portability = Nothing
   , hmi_safety      = Nothing
+  , hmi_language    = Nothing
+  , hmi_extensions  = []
   }
 
 
@@ -450,6 +456,7 @@ data DocOption
   | OptIgnoreExports   -- ^ Pretend everything is exported.
   | OptNotHome         -- ^ Not the best place to get docs for things
                        -- exported by this module.
+  | OptShowExtensions  -- ^ Render enabled extensions for this module.
   deriving (Eq, Show)