export hGetBufSome (#4046)

[ghc-base.git] / Control / Monad.hs

diff --git a/Control/Monad.hs b/Control/Monad.hs
index c44ac82..8972ca1 100644 (file)
--- a/Control/Monad.hs
+++ b/Control/Monad.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS_GHC -fno-implicit-prelude #-}
+{-# OPTIONS_GHC -XNoImplicitPrelude #-}
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Control.Monad
@@ -40,6 +40,7 @@ module Control.Monad
     , (>=>)         -- :: (Monad m) => (a -> m b) -> (b -> m c) -> (a -> m c)
     , (<=<)         -- :: (Monad m) => (b -> m c) -> (a -> m b) -> (a -> m c)
     , forever       -- :: (Monad m) => m a -> m b
+    , void
 
     -- ** Generalisations of list functions
 
@@ -190,6 +191,10 @@ f >=> g     = \x -> f x >>= g
 forever     :: (Monad m) => m a -> m b
 forever a   = a >> forever a
 
+-- | @'void' value@ discards or ignores the result of evaluation, such as the return value of an 'IO' action.
+void :: Functor f => f a -> f ()
+void = fmap (const ())
+
 -- -----------------------------------------------------------------------------
 -- Other monad functions