From 2069ba2fe676247f67155a39507d3c23a352ffb1 Mon Sep 17 00:00:00 2001 From: simonpj Date: Tue, 13 May 2003 11:42:47 +0000 Subject: [PATCH] [project @ 2003-05-13 11:42:47 by simonpj] Generalise the type of listens slightly; a suggestion from Tom Pledger --- Control/Monad/Writer.hs | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Control/Monad/Writer.hs b/Control/Monad/Writer.hs index 79ec97e..b941e65 100644 --- a/Control/Monad/Writer.hs +++ b/Control/Monad/Writer.hs @@ -59,7 +59,7 @@ class (Monoid w, Monad m) => MonadWriter w m | m -> w where listen :: m a -> m (a, w) pass :: m (a, w -> w) -> m a -listens :: (MonadWriter w m) => (w -> w) -> m a -> m (a, w) +listens :: (MonadWriter w m) => (w -> b) -> m a -> m (a, b) listens f m = do (a, w) <- listen m return (a, f w) -- 1.7.10.4