Changes between Version 1 and Version 2 of coroutine-iteratee

Timestamp:

11/28/10 19:22:04 (2 years ago)

Author:

blamario (IP: 99.241.117.248)

Comment:

--

coroutine-iteratee

@@ -1 +1 @@
 = coroutine-iteratee =
 
-The coroutine-iteratee package can be used as a bridge between the [http://hackage.haskell.org/package/iteratee iteratee] and [wiki:monad-coroutine] packages. It provides two-way conversion functions between an Iteratee and an Await-suspending coroutine, and also
-between an Enumerator and a Yield-suspending coroutine.
+The coroutine-iteratee package can be used as a bridge between the [http://hackage.haskell.org/package/iteratee iteratee] and [wiki:monad-coroutine] packages. It provides two-way conversion functions between an Iteratee and an Await-suspending coroutine, and also between an Enumerator and a Yield-suspending coroutine.
+
+    The function signatures are compatible with the [wiki:coroutine-enumerator] package, so the two packages can be
+combined into a bridge between the existing enumerator-based and iteratee-based libraries:
+
+{{{
+import Data.Monoid (Monoid)
+import qualified Data.Enumerator as E
+import qualified Data.Iteratee as I
+import qualified Control.Monad.Coroutine.Enumerator as CE
+import qualified Control.Monad.Coroutine.Iteratee as CI
+import Control.Monad.Coroutine (Coroutine)
+import Control.Monad.Coroutine.SuspensionFunctors (Yield)
+
+iterateeI2E :: (Monoid s, Monad m) => I.Iteratee s m a -> E.Iteratee s m a
+iterateeI2E = CE.coroutineIteratee . CI.iterateeCoroutine
+
+iterateeE2I :: (Monoid s, Monad m) => E.Iteratee s m a -> I.Iteratee s m a
+iterateeE2I = CI.coroutineIteratee . CE.iterateeCoroutine
+enumeratorI2E :: (Monoid s, Monad m) => I.Enumerator s (Coroutine (Yield [s]) m) () -> E.Enumerator s m ()
+enumeratorI2E = CE.coroutineEnumerator . CI.enumeratorCoroutine
+
+enumeratorE2I :: (Monoid s, Monad m) => E.Enumerator s (Coroutine (Yield [s]) m) () -> I.Enumerator s m ()
+enumeratorE2I = CI.coroutineEnumerator . CE.enumeratorCoroutine
+}}}
+
+    Here's an example that uses `enumInflate` from the (iteratee-based) package `iteratee-compress`, together with the
+enumerator-based function `iterHandle`, to build an iteratee that writes data into a compressed file:
+
+{{{
+import Control.Monad ((>=>))
+import System.IO (Handle, withBinaryFile, IOMode(WriteMode))
+import Control.Monad.IO.Class (MonadIO(liftIO))
+import Data.ByteString (ByteString)
+import Data.ByteString.Char8 (pack)
+import Data.Enumerator.IO (iterHandle)
+import Data.Iteratee.ZLib (enumDeflate, Format(GZip), defaultCompressParams)
+
+iterCompressHandle :: MonadIO m => Handle -> m (I.Iteratee ByteString m ())
+iterCompressHandle = enumDeflate GZip defaultCompressParams . iterateeE2I . iterHandle
+
+main = withBinaryFile "hello.gz" WriteMode $
+       \h-> iterCompressHandle h
+       >>= I.enumPure1Chunk (pack "Hello, World!\n")
+       >>= foldr (>=>) return (replicate 10 $ I.enumPure1Chunk (pack "Salut, Monde!\n"))
+       >>= I.run
+}}}