Simplify querying

src/Control/Addressbook/Query.hs

@@ -4,15 +4,12 @@ module Control.Addressbook.Query where
 import Data.Text
        (Text)
 import qualified Data.Text as T
-import qualified Data.Text.Encoding as TE
 
 import Conduit
 import qualified Data.Conduit.Binary as CB
 import qualified Data.Conduit.Combinators as C
-import qualified Data.Conduit.List as CL
 import qualified Data.Conduit.Text as CT
 
-import qualified Data.Map.Strict as Map
 
 import System.IO
        (stdout)
@@ -26,27 +23,20 @@ import System.FilePath
 
 import Control.Exception
        (catch)
-import Data.ByteString (ByteString)
-import qualified Data.ByteString.Char8 as B
 
 -- XXX: The current Data.Trie implementation is much slower than Data.Set
 query :: Text -> IO ()
 query prefix = do
   datDir <- fromMaybe "./" <$> lookupEnv "HOME"
-  state <- catch @IOError (runResourceT $ runConduit $ readState datDir) (\_ -> pure Map.empty)
-  runConduit $ outputResults state
+  catch @IOError (runResourceT $ runConduit $ filterAddresses datDir) $ \e -> print e
   where
-    readState :: FilePath -> ConduitM () Void (ResourceT IO) (Map.Map ByteString [Text])
-    readState dir =
+    prefixLC = T.toLower prefix
+    filterAddresses :: FilePath -> ConduitT () Void (ResourceT IO) ()
+    filterAddresses dir =
       CB.sourceFile (dir </> ".addressbook.dat")
         .| CT.decode CT.utf8
         .| CT.lines
-        .| C.foldMap (\s -> Map.singleton (TE.encodeUtf8 $ T.toLower s) [s])
-    prefixB = TE.encodeUtf8 prefix
-    outputResults :: Map.Map ByteString [Text] -> ConduitM () Void IO ()
-    outputResults state =
-      CL.sourceList (Map.elems $ Map.filterWithKey (\k _ -> prefixB `B.isPrefixOf` k)  state)
-        .| C.concat
-        .| C.map (<> "\n")
+        .| C.filter (\v -> prefixLC `T.isPrefixOf` (T.toLower v))
         .| CT.encode CT.utf8
+        .| C.map (<> "\n")
         .| CB.sinkHandle stdout