Move an interface function with Cabal package into CabalApi module.

Cabal.hs

@@ -2,16 +2,13 @@
 
 module Cabal (initializeGHC) where
 
-import CabalApi (dependPackages)
+import CabalApi (cabalBuildInfo, cabalDependPackages)
 import Control.Applicative
 import Control.Exception
 import Control.Monad
 import CoreMonad
 import Data.List
-import Data.Maybe
+import Distribution.PackageDescription (BuildInfo(..), usedExtensions)
-import Distribution.PackageDescription
-import Distribution.PackageDescription.Parse (readPackageDescription)
-import Distribution.Verbosity (silent)
 import ErrMsg
 import GHC
 import GHCApi
@@ -34,7 +31,7 @@ initializeGHC opt fileName ghcOptions logging = withCabal ||> withoutCabal
         return (fileName,logReader)
     withCabal = do
         (owdir,cdir,cfile) <- liftIO getDirs
-        binfo@BuildInfo{..} <- liftIO $ parseCabalFile cfile
+        binfo@BuildInfo{..} <- liftIO $ cabalBuildInfo cfile
         let exts = map (addX . Gap.extensionToString) $ usedExtensions binfo
             lang = maybe "-XHaskell98" (addX . show) defaultLanguage
             libs = map ("-l" ++) extraLibs
@@ -43,26 +40,13 @@ initializeGHC opt fileName ghcOptions logging = withCabal ||> withoutCabal
             idirs = case hsSourceDirs of
                 []   -> [cdir,owdir]
                 dirs -> map (cdir </>) dirs ++ [owdir]
-        depPkgs   <- liftIO $ dependPackages cfile
+        depPkgs   <- liftIO $ cabalDependPackages cfile
         logReader <- initSession opt gopts idirs (Just depPkgs) logging
         return (fileName,logReader)
     addX = ("-X" ++)
 
 ----------------------------------------------------------------
 
--- Causes error, catched in the upper function.
-parseCabalFile :: FilePath -> IO BuildInfo
-parseCabalFile file = do
-    cabal <- readPackageDescription silent file
-    return . fromJust $ fromLibrary cabal <|> fromExecutable cabal
-  where
-    fromLibrary c     = libBuildInfo . condTreeData <$> condLibrary c
-    fromExecutable c  = buildInfo . condTreeData . snd <$> toMaybe (condExecutables c)
-    toMaybe [] = Nothing
-    toMaybe (x:_) = Just x
-
-----------------------------------------------------------------
-
 -- CurrentWorkingDir, CabalDir, CabalFile
 getDirs :: IO (FilePath,FilePath,FilePath)
 getDirs = do

CabalApi.hs

@@ -1,6 +1,11 @@
-module CabalApi (dependPackages) where
+module CabalApi (
+  cabalBuildInfo,
+  cabalDependPackages
+  ) where
 
-import Data.Maybe (maybeToList)
+import Control.Applicative
+
+import Data.Maybe (fromJust, maybeToList)
 import Data.Set (fromList, toList)
 
 import Distribution.Verbosity (silent)
@@ -8,11 +13,28 @@ import Distribution.Package (Dependency(Dependency), PackageName(PackageName))
 import Distribution.PackageDescription
   (GenericPackageDescription,
    condLibrary, condExecutables, condTestSuites, condBenchmarks,
-   CondTree, condTreeConstraints)
+   BuildInfo, usedExtensions, libBuildInfo, buildInfo,
+   CondTree, condTreeConstraints, condTreeData)
 import Distribution.PackageDescription.Parse (readPackageDescription)
 
+-- import Distribution.PackageDescription
+--   (BuildInfo(..))
+-- import Distribution.PackageDescription.Parse (readPackageDescription)
+-- import Distribution.Verbosity (silent)
+
 ----------------------------------------------------------------
 
+-- Causes error, catched in the upper function.
+cabalBuildInfo :: FilePath -> IO BuildInfo
+cabalBuildInfo file = do
+    cabal <- readPackageDescription silent file
+    return . fromJust $ fromLibrary cabal <|> fromExecutable cabal
+  where
+    fromLibrary c     = libBuildInfo . condTreeData <$> condLibrary c
+    fromExecutable c  = buildInfo . condTreeData . snd <$> toMaybe (condExecutables c)
+    toMaybe [] = Nothing
+    toMaybe (x:_) = Just x
+
 parseGenericDescription :: FilePath -> IO GenericPackageDescription
 parseGenericDescription =  readPackageDescription silent
 
@@ -31,8 +53,8 @@ allDependsOfDescription pd =
 getDependencyPackageName :: Dependency -> String
 getDependencyPackageName (Dependency (PackageName n) _) = n
 
-dependPackages :: FilePath -> IO [String]
+cabalDependPackages :: FilePath -> IO [String]
-dependPackages =
+cabalDependPackages =
   fmap (toList . fromList
         . map getDependencyPackageName
         . allDependsOfDescription)