X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=Data%2FHashTable.hs;h=0cee737d924ac376ef3fc2e5d8f224177891da76;hb=48b5ddb3fc2d52d172230da3916e1b06bf36eafa;hp=8ea79099f0b37726efbb247c59103cdcfdaf8e7f;hpb=1a3710614eec1bba6f241f44e9bf84249d43b58d;p=ghc-base.git

diff --git a/Data/HashTable.hs b/Data/HashTable.hs
index 8ea7909..0cee737 100644
--- a/Data/HashTable.hs
+++ b/Data/HashTable.hs
@@ -207,14 +207,14 @@ mulHi a b = fromIntegral (r `shiftR` 32)
 -- golden ratio and adding.  The implementation is:
 --
 -- > hashString = foldl' f 0
--- >   where f m c = fromIntegral (ord c) + mulHi m golden
---
+-- >   where f m c = fromIntegral (fromEnum c + 1) * golden + mulHi m golden
+-- 
 -- Note that this has not been extensively tested for reasonability,
 -- but Knuth argues that repeated multiplication by the golden ratio
 -- will minimize gaps in the hash space.
 hashString :: String -> Int32
 hashString = foldl' f 0
-  where f m c = fromIntegral (ord c) + mulHi m golden
+  where f m c = fromIntegral (ord c + 1) * golden + mulHi m golden
 
 -- | A prime larger than the maximum hash table size
 prime :: Int32