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authormarkus <unknown>2003-11-11 11:59:21 +0000
committermarkus <unknown>2003-11-11 11:59:21 +0000
commit9b47b4aa128a5cbee74aa99e5494a0b76890ec4a (patch)
tree0a870fa527b8fea0c98d6906d90ebac72872504a /src/GF/Data/RedBlack.hs
parentb5685411125cb5cafe86c7761b0632b83c25f449 (diff)
Added a collapse function to Trie
Diffstat (limited to 'src/GF/Data/RedBlack.hs')
-rw-r--r--src/GF/Data/RedBlack.hs5
1 files changed, 5 insertions, 0 deletions
diff --git a/src/GF/Data/RedBlack.hs b/src/GF/Data/RedBlack.hs
index 8a24c07a3..4ee1f92a6 100644
--- a/src/GF/Data/RedBlack.hs
+++ b/src/GF/Data/RedBlack.hs
@@ -10,6 +10,7 @@
module RedBlack (
emptyTree,
+ isEmpty,
Tree,
lookupTree,
insertTree,
@@ -32,6 +33,10 @@ balance color a x b = T color a x b
emptyTree :: Tree key el
emptyTree = E
+isEmpty :: Tree key el -> Bool
+isEmpty (E) = True
+isEmpty _ = False
+
lookupTree :: Ord a => a -> Tree a b -> Maybe b
lookupTree _ E = Nothing
lookupTree x (T _ a (y,z) b)