happstack-monad-peel (empty) → 0.1

raw patch · 4 files changed

+152/−0 lines, 4 filesdep +basedep +happstack-serverdep +monad-peelsetup-changed

Dependencies added: base, happstack-server, monad-peel, mtl, transformers

Files

• LICENSE +30/−0
• Setup.hs +6/−0
• happstack-monad-peel.cabal +33/−0
• src/Happstack/Server/MonadPeel.hs +83/−0

@@ -0,0 +1,30 @@+Copyright (c)2012, Nils Schweinsberg <mail@nils.cc>
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+
+    * Neither the name of Nils Schweinsberg nor the names of other
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

@@ -0,0 +1,6 @@+#!/usr/bin/env runhaskell
+
+import Distribution.Simple
+
+main :: IO ()
+main = defaultMainWithHooks simpleUserHooks

@@ -0,0 +1,33 @@+Name:                happstack-monad-peel
+Version:             0.1
+
+Synopsis:            monad-peel instances for Happstack types
+Description:         monad-peel instances for Happstack types
+
+License:             BSD3
+License-file:        LICENSE
+Author:              Nils Schweinsberg <mail@nils.cc>
+Maintainer:          mail@nils.cc
+-- Copyright:           
+
+Category:            Web, Happstack
+
+Build-type:          Simple
+Cabal-version:       >= 1.6
+
+-- Extra-source-files:  
+
+Library
+
+  HS-source-dirs:    src
+  GHC-options:       -Wall -O3
+
+  Build-depends:       
+    base == 4.*, mtl, transformers,
+    monad-peel,
+    happstack-server
+
+  Exposed-modules:
+    Happstack.Server.MonadPeel
+
+  Other-modules:

@@ -0,0 +1,83 @@+{-# LANGUAGE FlexibleInstances #-}
+{-# OPTIONS -fno-warn-orphans #-}
+
+{- |
+
+Module      :  Happstack.Server.MonadPeel
+Copyright   :  (c) Nils Schweinsberg, 2012
+License     :  BSD-style
+
+Maintainer  :  Nils Schweinsberg <mail@nils.cc>
+Stability   :  experimental
+Portability :  non-portable (extended exceptions)
+
+This module defines instances of 'MonadTransPeel' and 'MonadPeelIO' for
+Happstacks data types 'ServerPartT', 'FilterT' and 'WebT'.
+
+To use these instances, add
+
+> import Happstack.Server.MonadPeel ()
+
+to the import list of your Haskell module.
+
+-}
+
+module Happstack.Server.MonadPeel
+  (
+  ) where
+
+import Control.Monad.Error
+import Control.Monad.Writer
+import Control.Monad.Reader
+import Control.Monad.Trans.Peel
+import Control.Monad.Trans.Maybe
+import Control.Monad.IO.Peel
+import Happstack.Server.Internal.Monads
+import Happstack.Server.Internal.Types
+
+
+--------------------------------------------------------------------------------
+-- TransPeel instances
+
+instance MonadTransPeel (FilterT (FilterFun a)) where
+  peel = return $ \m -> do
+    (x,w) <- runWriterT $ unFilterT m
+    return $ FilterT $ do
+      tell w
+      return x
+
+instance MonadTransPeel WebT where
+  peel = return $ \m -> do
+    mxew <- runMaybeT $ runWriterT $ unFilterT $ runErrorT $ unWebT m
+    return $ WebT $
+      case mxew of
+           Just (x,_) ->
+             case x of
+                  Right a -> return a
+                  Left  b -> throwError b
+           Nothing -> mzero
+
+runWebT :: WebT m a -> m (Maybe (Either Response a, FilterFun Response))
+runWebT m =
+  runMaybeT $ runWriterT $ unFilterT $ runErrorT $ unWebT m
+
+instance MonadTransPeel ServerPartT where
+  peel = ServerPartT $ asks $ \r m -> do
+    x <- runWebT $ runReaderT (unServerPartT m) r
+    return $
+      case x of
+           Just (Right a,_) -> return a
+           _                -> mzero
+
+
+--------------------------------------------------------------------------------
+-- PeelIO instances
+
+instance MonadPeelIO m => MonadPeelIO (FilterT (FilterFun a) m) where
+  peelIO = liftPeel peelIO
+
+instance MonadPeelIO m => MonadPeelIO (WebT m) where
+  peelIO = liftPeel peelIO
+
+instance MonadPeelIO m => MonadPeelIO (ServerPartT m) where
+  peelIO = liftPeel peelIO