Network.Wai.Trans

Simple utilities for embedding a monad transformer stack in an Application or Middleware - with MiddlewareT, your transformer stack is shared across all attached middlewares until run. You can also lift existing Middleware to MiddlewareT, given some extraction function.

WAI

Types

module Network.Wai

type ApplicationT m = Request -> (Response -> m ResponseReceived) -> m ResponseReceived

Isomorphic to Kleisli (ContT ResponseReceived m) Request Response

type MiddlewareT m = ApplicationT m -> ApplicationT m

Embedding

liftApplication :: MonadIO m => (forall a. m a -> IO a) -> Application -> ApplicationT m

liftMiddleware :: MonadIO m => (forall a. m a -> IO a) -> Middleware -> MiddlewareT m

runApplicationT :: MonadIO m => (forall a. m a -> IO a) -> ApplicationT m -> Application

runMiddlewareT :: MonadIO m => (forall a. m a -> IO a) -> MiddlewareT m -> Middleware

hoistApplicationT :: (Monad m, Monad n) => (forall a. m a -> n a) -> (forall a. n a -> m a) -> ApplicationT m -> ApplicationT n

hoistMiddlewareT :: (Monad m, Monad n) => (forall a. m a -> n a) -> (forall a. n a -> m a) -> MiddlewareT m -> MiddlewareT n

Exception catching

catchApplicationT :: (MonadCatch m, Exception e) => ApplicationT m -> (e -> ApplicationT m) -> ApplicationT m

catchMiddlewareT :: (MonadCatch m, Exception e) => MiddlewareT m -> (e -> MiddlewareT m) -> MiddlewareT m

General Purpose

readingRequest :: Monad m => (Request -> m ()) -> MiddlewareT m

Websockets

type ServerAppT m = PendingConnection -> m ()

websocketsOrT :: MonadIO m => (forall a. m a -> IO a) -> ConnectionOptions -> ServerAppT m -> MiddlewareT m

Respond with the WebSocket server when applicable, as a middleware