X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;ds=sidebyside;f=compiler%2Futils%2FIOEnv.hs;h=a87413b347c09a61349e81a697c967ad3cf04859;hb=cf05b97f5c181059418c53e43fab946734cfb41d;hp=30cc28b42ff5adff0cd0fa142d5401855387f396;hpb=7fc749a43b4b6b85d234fa95d4928648259584f4;p=ghc-hetmet.git

diff --git a/compiler/utils/IOEnv.hs b/compiler/utils/IOEnv.hs
index 30cc28b..a87413b 100644
--- a/compiler/utils/IOEnv.hs
+++ b/compiler/utils/IOEnv.hs
@@ -1,9 +1,3 @@
---
--- (c) The University of Glasgow 2002-2006
---
--- The IO Monad with an environment
---
-
 {-# OPTIONS -w #-}
 -- The above warning supression flag is a temporary kludge.
 -- While working on this module you are encouraged to remove it and fix
@@ -11,13 +5,19 @@
 --     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
 -- for details
 
+--
+-- (c) The University of Glasgow 2002-2006
+--
+-- The IO Monad with an environment
+--
+
 module IOEnv (
 	IOEnv,	-- Instance of Monad
 
 	-- Standard combinators, specialised
 	returnM, thenM, thenM_, failM, failWithM,
 	mappM, mappM_, mapSndM, sequenceM, sequenceM_, 
-	foldlM, foldrM,
+	foldlM, foldrM, anyM,
 	mapAndUnzipM, mapAndUnzip3M, 
 	checkM, ifM, zipWithM, zipWithM_,
 
@@ -99,7 +99,9 @@ fixM f = IOEnv (\ env -> fixIO (\ r -> unIOEnv (f r) env))
 
 ---------------------------
 tryM :: IOEnv env r -> IOEnv env (Either Exception r)
--- Reflect UserError exceptions into IOEnv monad
+-- Reflect UserError exceptions (only) into IOEnv monad
+-- Other exceptions are not caught; they are simply propagated as exns
+--
 -- The idea is that errors in the program being compiled will give rise
 -- to UserErrors.  But, say, pattern-match failures in GHC itself should
 -- not be caught here, else they'll be reported as errors in the program 
@@ -174,6 +176,7 @@ mapAndUnzipM  :: (a -> IOEnv env (b,c))   -> [a] -> IOEnv env ([b],[c])
 mapAndUnzip3M :: (a -> IOEnv env (b,c,d)) -> [a] -> IOEnv env ([b],[c],[d])
 checkM	      :: Bool -> IOEnv env a -> IOEnv env ()	-- Perform arg if bool is False
 ifM	      :: Bool -> IOEnv env a -> IOEnv env ()	-- Perform arg if bool is True
+anyM	      :: (a -> IOEnv env Bool) -> [a] -> IOEnv env Bool
 
 mappM f []     = return []
 mappM f (x:xs) = do { r <- f x; rs <- mappM f xs; return (r:rs) }
@@ -184,6 +187,10 @@ mapSndM f ((a,b):xs) = do { c <- f b; rs <- mapSndM f xs; return ((a,c):rs) }
 mappM_ f []     = return ()
 mappM_ f (x:xs) = f x >> mappM_ f xs
 
+anyM f [] = return False
+anyM f (x:xs) = do { b <- f x; if b then return True 
+				    else anyM f xs }
+
 zipWithM :: (a -> b -> IOEnv env c) -> [a] -> [b] -> IOEnv env [c]
 zipWithM f [] bs = return []
 zipWithM f as [] = return []