Rewrite config file searching a bit

See #21

1 files changed, 20 insertions, 32 deletions

diff --git a/src/Language/Haskell/Stylish/Config.hs b/src/Language/Haskell/Stylish/Config.hs
index ad2ae61..6c05e0a 100644
--- a/src/Language/Haskell/Stylish/Config.hs
+++ b/src/Language/Haskell/Stylish/Config.hs
@@ -11,7 +11,7 @@ module Language.Haskell.Stylish.Config
 
 --------------------------------------------------------------------------------
 import           Control.Applicative                    (pure, (<$>), (<*>))
-import           Control.Monad                          (forM, msum, mzero)
+import           Control.Monad                          (forM, mzero)
 import           Data.Aeson                             (FromJSON (..))
 import qualified Data.Aeson                             as A
 import qualified Data.Aeson.Types                       as A
@@ -71,38 +71,26 @@ defaultConfigFilePath = getDataFileName "data/stylish-haskell.yaml"
 
 --------------------------------------------------------------------------------
 configFilePath :: Verbose -> Maybe FilePath -> IO (Maybe FilePath)
-configFilePath verbose userSpecified = do
-    (current, currentE)         <- check $ (</> configFileName) <$>
-                                   getCurrentDirectory
-    (projectRoot, projectRootE) <- checkUntilFound =<< (map (</> configFileName))
-                                   <$> getAncestorDirectories
-    (home, homeE)               <- check $ (</> configFileName) <$>
-                                   getHomeDirectory
-    (def, defE)                 <- check defaultConfigFilePath
-    return $ msum
-        [ userSpecified
-        , if currentE then Just current else Nothing
-        , if projectRootE then Just projectRoot else Nothing
-        , if homeE then Just home else Nothing
-        , if defE then Just def else Nothing
-        ]
+configFilePath _       (Just userSpecified) = return $ Just userSpecified
+configFilePath verbose Nothing              = do
+    current <- getCurrentDirectory
+    home    <- getHomeDirectory
+    def     <- defaultConfigFilePath
+    search $
+        [d </> configFileName | d <- ancestors current] ++
+        [home </> configFileName, def]
   where
-    getAncestorDirectories :: IO [FilePath]
-    getAncestorDirectories = map joinPath . reverse . drop 2
-                             . inits . splitPath <$> getCurrentDirectory
-
-    checkUntilFound :: [FilePath] -> IO (FilePath, Bool)
-    checkUntilFound []     = return ("", False)
-    checkUntilFound (f:fs) = do
-      res@(_, ex) <- check (return f)
-      if ex then return res else checkUntilFound fs
-
-    check :: IO FilePath -> IO (FilePath, Bool)
-    check fp = do
-        fp' <- fp
-        ex  <- doesFileExist fp'
-        verbose $ fp' ++ if ex then " exists" else " does not exist"
-        return (fp', ex)
+    -- All ancestors of a dir (including that dir)
+    ancestors :: FilePath -> [FilePath]
+    ancestors = init . map joinPath . reverse . inits . splitPath
+
+    search :: [FilePath] -> IO (Maybe FilePath)
+    search []       = return Nothing
+    search (f : fs) = do
+        -- TODO Maybe catch an error here, dir might be unreadable
+        exists <- doesFileExist f
+        verbose $ f ++ if exists then " exists" else " does not exist"
+        if exists then return (Just f) else search fs
 
 
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