[project @ 1997-10-05 21:32:07 by sof]

Added missing zipWithM_

ghc/lib/required/Monad.lhs

@@ -18,6 +18,7 @@ module Monad (
     join,           -- ::(Monadm)=>m(ma)->ma
     mapAndUnzipM,   -- ::(Monadm)=>(a->m(b,c))->[a]->m([b],[c])
     zipWithM,       -- ::(Monadm)=>(a->b->mc)->[a]->[b]->m[c]
+    zipWithM_,	    -- :: (Monad m) => (a -> b -> m c) -> [a] -> [b] -> m ()
     foldM,          -- ::(Monadm)=>(a->b->ma)->a->[b]->ma 
     when,           -- ::(Monadm)=>Bool->m()->m()
     unless,         -- ::(Monadm)=>Bool->m()->m()
@@ -86,6 +87,9 @@ mapAndUnzipM f xs = accumulate (map f xs) >>= return . unzip
 zipWithM         :: (Monad m) => (a -> b -> m c) -> [a] -> [b] -> m [c]
 zipWithM f xs ys = accumulate (zipWith f xs ys)
 
+zipWithM_ :: (Monad m) => (a -> b -> m c) -> [a] -> [b] -> m ()
+zipWithM_ f xs ys = sequence (zipWith f xs ys)
+
 foldM            :: (Monad m) => (a -> b -> m a) -> a -> [b] -> m a
 foldM f a []     = return a
 foldM f a (x:xs) = f a x >>= \fax -> foldM f fax xs