export minimum Monad stuff from GhcMod.

Language/Haskell/GhcMod.hs

@@ -15,7 +15,12 @@ module Language.Haskell.GhcMod (
   , GhcPkgDb
   , Symbol
   , SymbolDb
-  , module Language.Haskell.GhcMod.Monad
+  -- * Monad Types
+  , GhcModT
+  , IOish
+  -- * Monad utilities
+  , runGhcModT
+  , withOptions
   -- * 'GhcMod' utilities
   , boot
   , browse

Language/Haskell/GhcMod/Logger.hs

@@ -79,7 +79,7 @@ withLogger setDF body = ghandle sourceError $ do
 sourceError :: IOish m => SourceError -> GhcModT m (Either String String)
 sourceError err = do
     dflags <- G.getSessionDynFlags
-    style <- toGhcMod getStyle
+    style <- toGhcModT getStyle
     ret <- convert' (errBagToStrList dflags style . srcErrorMessages $ err)
     return $ Left ret
 

Language/Haskell/GhcMod/Monad.hs

@@ -23,12 +23,13 @@ module Language.Haskell.GhcMod.Monad (
   , withErrorHandler
   -- ** Conversion
   , liftGhcMod
-  , toGhcMod
+  , toGhcModT
   -- ** Accessing 'GhcModEnv' and 'GhcModState'
   , options
   , cradle
   , getMode
   , setMode
+  , withOptions
   -- ** Exporting convenient modules
   , module Control.Monad.Reader.Class
   , module Control.Monad.Writer.Class
@@ -274,8 +275,8 @@ withErrorHandler label = ghandle ignore
         exitSuccess
 
 -- | This is only a transitional mechanism don't use it for new code.
-toGhcMod :: IOish m => Ghc a -> GhcModT m a
-toGhcMod a = do
+toGhcModT :: IOish m => Ghc a -> GhcModT m a
+toGhcModT a = do
     s <- gmGhcSession <$> ask
     liftIO $ unGhc a $ Session s
 
@@ -297,6 +298,15 @@ setMode mode = put $ GhcModState mode
 
 ----------------------------------------------------------------
 
+withOptions :: IOish m => (Options -> Options) -> GhcModT m a -> GhcModT m a
+withOptions changeOpt action = local changeEnv action
+  where
+    changeEnv e = e { gmOptions = changeOpt opt }
+      where
+        opt = gmOptions e
+
+----------------------------------------------------------------
+
 instance (MonadBaseControl IO m) => MonadBase IO (GhcModT m) where
     liftBase = GhcModT . liftBase