+p8

1 files changed, 12 insertions, 0 deletions

diff --git a/p8.hs b/p8.hs
new file mode 100644
index 0000000..219bc93
--- /dev/null
+++ b/p8.hs
@@ -0,0 +1,12 @@
+compress :: (Eq a) => [a] -> [a]
+compress = foldr elim []
+  where elim e [] = [e]
+        elim e ns
+          | e == head ns = ns 
+          | otherwise = e:ns
+
+compress' xs = foldr f (const []) xs Nothing
+  where
+    f x r a@(Just q) 
+      | x == q = r a
+    f x r _ = x : r (Just x)