Handle failures properly

Attoparsec error are discarded since they are basically useless.

src/Main.hs

@@ -32,15 +32,19 @@ fuzzy x = filter (any (isInfixOf x) . strings)
 -- Keychain access --
 
 keychainList :: IO [FilePath]
-keychainList =
-  runParser parseKeychainList <$>
-  readProcess "security" ["list-keychains"] ""
+keychainList = do
+  raw <- readProcess "security" ["list-keychains"] ""
+  case runParser parseKeychainList raw of
+    Just list -> return list
+    Nothing   -> error "failed to parse active keychains list"
 
 getKeychain :: IO Keychain
 getKeychain = do
   paths <- filter ((/="System") . takeBaseName) <$> keychainList
-  dump  <- readProcess "security" ("dump-keychain" : "-d" : paths) ""
-  return (runParser parseKeychain dump)
+  raw   <- readProcess "security" ("dump-keychain" : "-d" : paths) ""
+  case runParser parseKeychain raw of
+    Just items -> return items
+    Nothing    -> error "failed to parse keychain"
 
 sendClipboard :: String -> IO ()
 sendClipboard text =

src/Parser.hs

@@ -14,11 +14,11 @@ import Data.Hex              (unhex)
 import Data.Time
 
 
-runParser :: Monoid a => Parser a -> String -> a
+runParser :: Parser a -> String -> Maybe a
 runParser parser = handle . parseOnly parser . pack
   where
-    handle (Left  _) = mempty
-    handle (Right x) = x
+    handle (Left  _) = Nothing
+    handle (Right x) = Just x
 
 
 -- Parsers --