Make parseCabalFile use MonadError

Language/Haskell/GhcMod/CabalApi.hs

@@ -11,14 +11,16 @@ module Language.Haskell.GhcMod.CabalApi (
   ) where
 
 import Language.Haskell.GhcMod.CabalConfig
-import Language.Haskell.GhcMod.Gap (benchmarkBuildInfo, benchmarkTargets, toModuleString)
+import Language.Haskell.GhcMod.Gap (benchmarkBuildInfo, benchmarkTargets,
+                                    toModuleString)
 import Language.Haskell.GhcMod.GhcPkg
 import Language.Haskell.GhcMod.Types
 
 import Control.Applicative ((<$>))
 import qualified Control.Exception as E
 import Control.Monad (filterM)
-import CoreMonad (liftIO)
+import Control.Monad.IO.Class (MonadIO, liftIO)
+import Control.Monad.Error.Class (MonadError(..))
 import Data.Maybe (maybeToList)
 import Data.Set (fromList, toList)
 import Distribution.Package (Dependency(Dependency)
@@ -71,17 +73,20 @@ includeDirectories cdir wdir dirs = uniqueAndSort (extdirs ++ [cdir,wdir])
 
 -- | Parsing a cabal file and returns 'PackageDescription'.
 --   'IOException' is thrown if parsing fails.
-parseCabalFile :: FilePath -> IO PackageDescription
+parseCabalFile :: (MonadIO m, MonadError GhcModError m)
+               => FilePath
+               -> m PackageDescription
 parseCabalFile file = do
-    cid <- getGHCId
-    epgd <- readPackageDescription silent file
+    cid <- liftIO $ getGHCId
+    epgd <- liftIO $ readPackageDescription silent file
     case toPkgDesc cid epgd of
-        Left deps    -> E.throwIO $ userError $ show deps ++ " are not installed"
+        Left deps    -> throwError $ GMECabal $ show deps ++ " are not installed"
         Right (pd,_) -> if nullPkg pd
-                        then E.throwIO $ userError $ file ++ " is broken"
+                        then throwError $ GMECabal $ file ++ " is broken"
                         else return pd
   where
-    toPkgDesc cid = finalizePackageDescription [] (const True) buildPlatform cid []
+    toPkgDesc cid =
+        finalizePackageDescription [] (const True) buildPlatform cid []
     nullPkg pd = name == ""
       where
         PackageName name = C.pkgName (P.package pd)

Language/Haskell/GhcMod/Debug.hs

@@ -31,9 +31,9 @@ debugInfo = cradle >>= \c -> convert' =<< do
   where
     simpleCompilerOption = options >>= \op ->
         return $ CompilerOptions (ghcOpts op) [] []
-    fromCabalFile c = options >>= \opts -> liftIO $ do
+    fromCabalFile c = options >>= \opts -> do
         pkgDesc <- parseCabalFile $ fromJust $ cradleCabalFile c
-        getCompilerOptions (ghcOpts opts) c pkgDesc
+        liftIO $ getCompilerOptions (ghcOpts opts) c pkgDesc
 
 ----------------------------------------------------------------
 

Language/Haskell/GhcMod/Monad.hs

@@ -187,7 +187,7 @@ instance MonadIO m => MonadIO (MaybeT m) where
 -- | Initialize the 'DynFlags' relating to the compilation of a single
 -- file or GHC session according to the 'Cradle' and 'Options'
 -- provided.
-initializeFlagsWithCradle :: GhcMonad m
+initializeFlagsWithCradle :: (GhcMonad m, MonadError GhcModError m)
         => Options
         -> Cradle
         -> m ()
@@ -199,7 +199,7 @@ initializeFlagsWithCradle opt c
     cabal = isJust mCradleFile
     ghcopts = ghcOpts opt
     withCabal = do
-        pkgDesc <- liftIO $ parseCabalFile $ fromJust mCradleFile
+        pkgDesc <- parseCabalFile $ fromJust mCradleFile
         compOpts <- liftIO $ getCompilerOptions ghcopts c pkgDesc
         initSession CabalPkg opt compOpts
     withSandbox = initSession SingleFile opt compOpts