1 files changed, 36 insertions, 0 deletions
diff --git a/testsuite/tests/lib/Data.ByteString/bytestring003.hs b/testsuite/tests/lib/Data.ByteString/bytestring003.hs
new file mode 100644
index 0000000000..c31ab8d17f
--- /dev/null
+++ b/testsuite/tests/lib/Data.ByteString/bytestring003.hs
@@ -0,0 +1,36 @@
+{-# OPTIONS -cpp #-}
+
+--
+-- 'sums' benchmark from the great language shootout 
+--
+
+import System.IO
+import qualified Data.ByteString as B
+import Data.ByteString (ByteString)
+import Data.ByteString.Unsafe (unsafeTail,unsafeIndex)
+import Data.Char    -- seems to help!
+
+#define STRICT2(f) f a b | a `seq` b `seq` False = undefined
+
+main = print . go 0 =<< B.getContents
+
+STRICT2(go)
+go i ps
+    | B.null ps = i
+    | x == 45   = neg 0 xs
+    | otherwise = pos (parse x) xs
+    where
+        (x, xs) = (ps `unsafeIndex` 0, unsafeTail ps)
+
+        STRICT2(neg)
+        neg n qs | x == 10     = go (i-n) xs
+                 | otherwise   = neg (parse x + (10 * n)) xs
+                 where (x, xs) = (qs `unsafeIndex` 0, unsafeTail qs)
+
+        STRICT2(pos)
+        pos n qs | x == 10   = go (i+n) xs
+                 | otherwise = pos (parse x + (10 * n)) xs
+                 where (x, xs) = (qs `unsafeIndex` 0, unsafeTail qs)
+
+parse w = fromIntegral (w - 48) :: Int
+{-# INLINE parse #-}