Fix warnings in utils/Util

[ghc-hetmet.git] / compiler / utils / IOEnv.hs

diff --git a/compiler/utils/IOEnv.hs b/compiler/utils/IOEnv.hs
index 728e55c..a87413b 100644 (file)
--- a/compiler/utils/IOEnv.hs
+++ b/compiler/utils/IOEnv.hs
@@ -17,7 +17,7 @@ module IOEnv (
        -- 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 []