Start adding DT versions of LDT functions

src/Dodge/DoubleTree.hs

@@ -15,6 +15,21 @@ singleLDT x = LDT x [] []
 ldtToDT :: LDTree b a -> DTree a
 ldtToDT (LDT x l r) = DT x (map (ldtToDT . snd) l) (map (ldtToDT . snd) r)
 
+dtStartPropagate :: (a -> c) -> (c -> a -> c) -> DTree a -> DTree c
+dtStartPropagate g f (DT x l r) = DT z 
+    (fmap (\(t) -> (dtPropagate' z f t)) l)
+    (fmap (\(t) -> (dtPropagate' z f t)) r)
+  where
+    z = g x
+ 
+
+dtPropagate' :: c -> (c -> a -> c) -> DTree a -> DTree c
+dtPropagate' x f (DT y l r) = DT z 
+    (fmap (\(t) -> (dtPropagate' z f t)) l)
+    (fmap (\(t) -> (dtPropagate' z f t)) r)
+  where
+    z = f x y
+
 ldtStartPropagate :: (a -> c) -> (c -> b -> a -> c) -> LDTree b a -> LDTree b c
 ldtStartPropagate g f (LDT x l r) = LDT z 
     (fmap (\(j,t) -> (j,ldtPropagate' z j f t)) l)