[project @ 2000-10-24 08:40:09 by simonpj]

[ghc-hetmet.git] / ghc / compiler / utils / Maybes.lhs

diff --git a/ghc/compiler/utils/Maybes.lhs b/ghc/compiler/utils/Maybes.lhs
index abaf1c1..3f94d34 100644 (file)
--- a/ghc/compiler/utils/Maybes.lhs
+++ b/ghc/compiler/utils/Maybes.lhs
@@ -15,13 +15,10 @@ module Maybes (
        expectJust,
        maybeToBool,
 
-       failMaB,
-       failMaybe,
-       seqMaybe,
-       returnMaB,
-       returnMaybe,
-       thenMaB,
-       catMaybes
+       thenMaybe, seqMaybe, returnMaybe, failMaybe, catMaybes,
+
+       thenMaB, returnMaB, failMaB
+
     ) where
 
 #include "HsVersions.h"
@@ -104,6 +101,11 @@ seqMaybe :: Maybe a -> Maybe a -> Maybe a
 seqMaybe (Just x) _  = Just x
 seqMaybe Nothing  my = my
 
+thenMaybe :: Maybe a -> (a -> Maybe b) -> Maybe b
+thenMaybe ma mb = case ma of
+                   Just x  -> mb x
+                   Nothing -> Nothing
+
 returnMaybe :: a -> Maybe a
 returnMaybe = Just