[project @ 2004-08-13 13:04:50 by simonmar]

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

diff --git a/ghc/compiler/utils/OrdList.lhs b/ghc/compiler/utils/OrdList.lhs
index 3e68eb7..7f22b38 100644 (file)
--- a/ghc/compiler/utils/OrdList.lhs
+++ b/ghc/compiler/utils/OrdList.lhs
@@ -11,7 +11,7 @@ can be appended in linear time.
 module OrdList (
        OrdList, 
         nilOL, isNilOL, unitOL, appOL, consOL, snocOL, concatOL,
-        fromOL, toOL, foldOL
+        fromOL, toOL, foldrOL, foldlOL
 ) where
 
 infixl 5  `appOL`
@@ -48,11 +48,26 @@ appOL None bs   = bs
 appOL as   None = as
 appOL as   bs   = Two as bs
 
-foldOL :: (a->b->b) -> b -> OrdList a -> b
-foldOL k z None        = z
-foldOL k z (One x)     = k x z
-foldOL k z (Two b1 b2) = foldOL k (foldOL k z b2) b1
-foldOL k z (Many xs)   = foldr k z xs
+mapOL :: (a -> b) -> OrdList a -> OrdList b
+mapOL f None = None
+mapOL f (One x) = One (f x)
+mapOL f (Two x y) = Two (mapOL f x) (mapOL f y)
+mapOL f (Many xs) = Many (map f xs)
+
+instance Functor OrdList where
+  fmap = mapOL
+
+foldrOL :: (a->b->b) -> b -> OrdList a -> b
+foldrOL k z None        = z
+foldrOL k z (One x)     = k x z
+foldrOL k z (Two b1 b2) = foldrOL k (foldrOL k z b2) b1
+foldrOL k z (Many xs)   = foldr k z xs
+
+foldlOL :: (b->a->b) -> b -> OrdList a -> b
+foldlOL k z None        = z
+foldlOL k z (One x)     = k z x
+foldlOL k z (Two b1 b2) = foldlOL k (foldlOL k z b1) b2
+foldlOL k z (Many xs)   = foldl k z xs
 
 fromOL :: OrdList a -> [a]
 fromOL ol