[project @ 1997-05-19 00:12:10 by sof]

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

diff --git a/ghc/compiler/utils/Maybes.lhs b/ghc/compiler/utils/Maybes.lhs
index 5ed4ac3..2542141 100644 (file)
--- a/ghc/compiler/utils/Maybes.lhs
+++ b/ghc/compiler/utils/Maybes.lhs
@@ -12,8 +12,8 @@ module Maybes (
 --     Maybe(..), -- no, it's in 1.3
        MaybeErr(..),
 
+       mapMaybe,
        allMaybes,
-       catMaybes,
        firstJust,
        expectJust,
        maybeToBool,
@@ -28,7 +28,9 @@ module Maybes (
        returnMaybe,
        thenMaB
 
-#if ! defined(COMPILING_GHC)
+#if defined(COMPILING_GHC)
+       , catMaybes
+#else
        , findJust
        , foldlMaybeErrs
        , listMaybeErrs
@@ -37,10 +39,13 @@ module Maybes (
 
 #if defined(COMPILING_GHC)
 
-CHK_Ubiq() -- debugging consistency check
+CHK_Ubiq()                     -- debugging consistency check
 
-import Unique (Unique) -- only for specialising
+IMPORT_DELOOPER( SpecLoop )    -- Specialisation
+import Unique  (Unique)                -- only for specialising
 
+#else
+import Maybe -- renamer will tell us if there are any conflicts
 #endif
 \end{code}
 
@@ -63,10 +68,12 @@ a list of @Justs@ into a single @Just@, returning @Nothing@ if there
 are any @Nothings@.
 
 \begin{code}
+#ifdef COMPILING_GHC
 catMaybes :: [Maybe a] -> [a]
 catMaybes []               = []
 catMaybes (Nothing : xs)   = catMaybes xs
 catMaybes (Just x : xs)           = (x : catMaybes xs)
+#endif
 
 allMaybes :: [Maybe a] -> Maybe [a]
 allMaybes [] = Just []
@@ -74,6 +81,12 @@ allMaybes (Nothing : ms) = Nothing
 allMaybes (Just x  : ms) = case (allMaybes ms) of
                             Nothing -> Nothing
                             Just xs -> Just (x:xs)
+
+mapMaybe :: (a -> Maybe b) -> [a] -> [b]
+mapMaybe f [] = []
+mapMaybe f (x:xs) = case f x of
+                       Just y  -> y : mapMaybe f xs
+                       Nothing -> mapMaybe f xs
 \end{code}
 
 @firstJust@ takes a list of @Maybes@ and returns the
@@ -135,7 +148,6 @@ assocMaybe alist key
        :: [(FAST_STRING,   b)] -> FAST_STRING -> Maybe b
         , [(Int,           b)] -> Int         -> Maybe b
         , [(Unique,        b)] -> Unique      -> Maybe b
-        , [(RdrName,       b)] -> RdrName     -> Maybe b
   #-}
 #endif
 \end{code}