From 3a97c2cbdba35bf954513d2c51b3e97d347b65a0 Mon Sep 17 00:00:00 2001 From: Michael Snoyman Date: Thu, 26 Dec 2013 17:32:21 +0200 Subject: [PATCH] Turn Action into a type synonym, not a newtype --- Database/MongoDB/Query.hs | 50 ++++++++++++--------------------------- 1 file changed, 15 insertions(+), 35 deletions(-) diff --git a/Database/MongoDB/Query.hs b/Database/MongoDB/Query.hs index 29ff2b3..f266562 100644 --- a/Database/MongoDB/Query.hs +++ b/Database/MongoDB/Query.hs @@ -46,7 +46,7 @@ module Database.MongoDB.Query ( import Prelude hiding (lookup) import Control.Applicative (Applicative, (<$>)) import Control.Exception (Exception, throwIO) -import Control.Monad (unless, replicateM, liftM) +import Control.Monad (unless, replicateM) import Data.Int (Int32) import Data.Maybe (listToMaybe, catMaybes) import Data.Word (Word32) @@ -60,13 +60,11 @@ import Control.Concurrent.MVar.Lifted (MVar, newMVar, mkWeakMVar, import Control.Concurrent.MVar.Lifted (MVar, newMVar, addMVarFinalizer, readMVar, modifyMVar) #endif -import Control.Monad.Base (MonadBase(liftBase)) +import Control.Monad.Base (MonadBase) import Control.Monad.Error (Error(..)) import Control.Monad.Reader (MonadReader, ReaderT, runReaderT, ask, asks, local) -import Control.Monad.Trans (MonadIO, MonadTrans, lift, liftIO) -import Control.Monad.Trans.Control (ComposeSt, MonadBaseControl(..), - MonadTransControl(..), StM, StT, - defaultLiftBaseWith, defaultRestoreM) +import Control.Monad.Trans (MonadIO, liftIO) +import Control.Monad.Trans.Control (MonadBaseControl(..)) import Data.Bson (Document, Field(..), Label, Val, Value(String, Doc, Bool), Javascript, at, valueAt, lookup, look, genObjectId, (=:), (=?)) @@ -91,30 +89,12 @@ import qualified Database.MongoDB.Internal.Protocol as P -- * Monad -newtype Action m a = Action {unAction :: ReaderT MongoContext m a} - deriving (Functor, Applicative, Monad, MonadIO) +type Action = ReaderT MongoContext -- ^ A monad on top of m (which must be a MonadIO) that may access the database and may fail with a DB 'Failure' -instance MonadBase b m => MonadBase b (Action m) where - liftBase = Action . liftBase - -instance (MonadIO m, MonadBaseControl b m) => MonadBaseControl b (Action m) where - newtype StM (Action m) a = StMT {unStMT :: ComposeSt Action m a} - liftBaseWith = defaultLiftBaseWith StMT - restoreM = defaultRestoreM unStMT - -instance MonadTrans Action where - lift = Action . lift - -instance MonadTransControl Action where - newtype StT Action a = StActionT {unStAction :: StT (ReaderT MongoContext) a} - liftWith f = Action $ liftWith $ \runReader' -> - f (liftM StActionT . runReader' . unAction) - restoreT = Action . restoreT . liftM unStAction - access :: (MonadIO m) => Pipe -> AccessMode -> Database -> Action m a -> m a -- ^ Run action against database on server at other end of pipe. Use access mode for any reads and writes. Return Left on connection failure or read/write failure. -access myPipe myAccessMode myDatabase (Action action) = runReaderT action MongoContext{..} +access myPipe myAccessMode myDatabase action = runReaderT action MongoContext{..} -- | A connection failure, or a read or write exception like cursor expired or inserting a duplicate key. -- Note, unexpected data from the server is not a Failure, rather it is a programming error (you should call 'error' in this case) because the client and server are incompatible and requires a programming change. @@ -154,7 +134,7 @@ slaveOk = ReadStaleOk accessMode :: (Monad m) => AccessMode -> Action m a -> Action m a -- ^ Run action with given 'AccessMode' -accessMode mode (Action act) = Action $ local (\ctx -> ctx {myAccessMode = mode}) act +accessMode mode act = local (\ctx -> ctx {myAccessMode = mode}) act readMode :: AccessMode -> ReadMode readMode ReadStaleOk = StaleOk @@ -179,13 +159,13 @@ myWriteMode = writeMode . myAccessMode send :: (MonadIO m) => [Notice] -> Action m () -- ^ Send notices as a contiguous batch to server with no reply. Throw 'ConnectionFailure' if pipe fails. -send ns = Action $ do +send ns = do pipe <- asks myPipe liftIOE ConnectionFailure $ P.send pipe ns call :: (MonadIO m) => [Notice] -> Request -> Action m (IO Reply) -- ^ Send notices and request as a contiguous batch to server and return reply promise, which will block when invoked until reply arrives. This call will throw 'ConnectionFailure' if pipe fails on send, and promise will throw 'ConnectionFailure' if pipe fails on receive. -call ns r = Action $ do +call ns r = do pipe <- asks myPipe promise <- liftIOE ConnectionFailure $ P.call pipe ns r return (liftIOE ConnectionFailure promise) @@ -198,7 +178,7 @@ instance HasMongoContext MongoContext where liftDB :: (MonadReader env m, HasMongoContext env, MonadIO m) => Action IO a -> m a -liftDB (Action m) = do +liftDB m = do env <- ask liftIO $ runReaderT m (mongoContext env) @@ -212,11 +192,11 @@ allDatabases = map (at "name") . at "databases" <$> useDb "admin" (runCommand1 " thisDatabase :: (Monad m) => Action m Database -- ^ Current database in use -thisDatabase = Action $ asks myDatabase +thisDatabase = asks myDatabase useDb :: (Monad m) => Database -> Action m a -> Action m a -- ^ Run action against given database -useDb db (Action act) = Action $ local (\ctx -> ctx {myDatabase = db}) act +useDb db act = local (\ctx -> ctx {myDatabase = db}) act -- * Authentication @@ -272,7 +252,7 @@ data WriteMode = write :: (MonadIO m) => Notice -> Action m () -- ^ Send write to server, and if write-mode is 'Safe' then include getLastError request and raise 'WriteFailure' if it reports an error. -write notice = Action (asks myWriteMode) >>= \mode -> case mode of +write notice = asks myWriteMode >>= \mode -> case mode of NoConfirm -> send [notice] Confirm params -> do let q = query (("getlasterror" =: (1 :: Int)) : params) "$cmd" @@ -483,7 +463,7 @@ distinct k (Select sel col) = at "values" <$> runCommand ["distinct" =: col, "ke queryRequest :: (Monad m) => Bool -> Query -> Action m (Request, Limit) -- ^ Translate Query to Protocol.Query. If first arg is true then add special $explain attribute. queryRequest isExplain Query{..} = do - ctx <- Action ask + ctx <- ask return $ queryRequest' (myReadMode ctx) (myDatabase ctx) where queryRequest' rm db = (P.Query{..}, remainingLimit) where @@ -535,7 +515,7 @@ fromReply limit Reply{..} = do fulfill :: (MonadIO m) => DelayedBatch -> Action m Batch -- ^ Demand and wait for result, raise failure if exception -fulfill = Action . liftIO +fulfill = liftIO -- *** Cursor