Add GHC-7.10 support

Language/Haskell/GhcMod/Modules.hs

@@ -1,32 +1,14 @@
 module Language.Haskell.GhcMod.Modules (modules) where
 
 import Control.Applicative ((<$>))
-import Control.Exception (SomeException(..))
-import Data.List (nub, sort)
 import qualified GHC as G
 import Language.Haskell.GhcMod.Convert
 import Language.Haskell.GhcMod.Monad
-import Language.Haskell.GhcMod.Types
-import Packages (pkgIdMap, exposedModules, sourcePackageId, display)
-import UniqFM (eltsUFM)
+import Language.Haskell.GhcMod.Gap (listVisibleModuleNames)
+import Module (moduleNameString)
 
 ----------------------------------------------------------------
 
 -- | Listing installed modules.
 modules :: IOish m => GhcModT m String
-modules = do
-    opt <- options
-    convert opt . arrange opt <$> (getModules `G.gcatch` handler)
-  where
-    getModules = getExposedModules <$> G.getSessionDynFlags
-    getExposedModules = concatMap exposedModules'
-                      . eltsUFM . pkgIdMap . G.pkgState
-    exposedModules' p =
-        map G.moduleNameString (exposedModules p)
-    	`zip`
-        repeat (display $ sourcePackageId p)
-    arrange opt = nub . sort . map (dropPkgs opt)
-    dropPkgs opt (name, pkg)
-      | detailed opt = name ++ " " ++ pkg
-      | otherwise = name
-    handler (SomeException _) = return []
+modules = convert' =<< map moduleNameString . listVisibleModuleNames <$> G.getSessionDynFlags