--- #prune
+{-# OPTIONS_HADDOCK prune #-}
-- |Aborting the computation of 'Network.HTTP.Lucu.Resource.Resource'
-- in any 'Prelude.IO' monads or arrows.
module Network.HTTP.Lucu.Abortion
( Abortion(..)
, abort
+ , abortPurely
, abortSTM
, abortA
, abortPage
import Control.Concurrent.STM
import Control.Exception
import Control.Monad.Trans
-import Data.ByteString.Base (ByteString)
+import qualified Data.ByteString.Char8 as C8
import Data.Dynamic
import GHC.Conc (unsafeIOToSTM)
import Network.HTTP.Lucu.Config
, aboMessage :: !(Maybe String)
} deriving (Show, Typeable)
+instance Exception Abortion
+
-- |Computation of @'abort' status headers msg@ aborts the
-- 'Network.HTTP.Lucu.Resource.Resource' monad with given status,
-- additional response headers, and optional message string.
--
--- What this really does is to just throw a special
--- 'Control.Exception.DynException'. The exception will be caught by
--- the Lucu.
+-- What this really does is to throw a special
+-- 'Control.Exception.Exception'. The exception will be caught by the
+-- Lucu system.
--
-- 1. If the 'Network.HTTP.Lucu.Resource.Resource' is in the /Deciding
-- Header/ or any precedent states, it is possible to use the
-- > abort MovedPermanently
-- > [("Location", "http://example.net/")]
-- > (Just "It has been moved to example.net")
-abort :: MonadIO m => StatusCode -> [ (ByteString, ByteString) ] -> Maybe String -> m a
+abort :: MonadIO m => StatusCode -> [ (String, String) ] -> Maybe String -> m a
abort status headers msg
= status `seq` headers `seq` msg `seq`
- let abo = Abortion status (toHeaders headers) msg
- exc = DynException (toDyn abo)
+ let abo = Abortion status (toHeaders $ map pack headers) msg
in
- liftIO $ throwIO exc
+ liftIO $ throwIO abo
+ where
+ pack (x, y) = (C8.pack x, C8.pack y)
+
+-- |This is similar to 'abort' but computes it with
+-- 'System.IO.Unsafe.unsafePerformIO'.
+abortPurely :: StatusCode -> [ (String, String) ] -> Maybe String -> a
+abortPurely = ((unsafePerformIO .) .) . abort
-- |Computation of @'abortSTM' status headers msg@ just computes
-- 'abort' in a 'Control.Monad.STM.STM' monad.
-abortSTM :: StatusCode -> [ (ByteString, ByteString) ] -> Maybe String -> STM a
+abortSTM :: StatusCode -> [ (String, String) ] -> Maybe String -> STM a
abortSTM status headers msg
= status `seq` headers `seq` msg `seq`
unsafeIOToSTM $! abort status headers msg
-- | Computation of @'abortA' -< (status, (headers, msg))@ just
-- computes 'abort' in an 'Control.Arrow.ArrowIO.ArrowIO'.
-abortA :: ArrowIO a => a (StatusCode, ([ (ByteString, ByteString) ], Maybe String)) c
+abortA :: ArrowIO a => a (StatusCode, ([ (String, String) ], Maybe String)) c
abortA
= arrIO3 abort
Nothing
-> let res' = res { resStatus = aboStatus abo }
res'' = foldl (.) id [setHeader name value
- | (name, value) <- fromHeaders $ aboHeaders abo]
- $ res'
+ | (name, value) <- fromHeaders $ aboHeaders abo] res'
in
getDefaultPage conf reqM res''