+-- > hashString = foldl' f golden
+-- > where f m c = fromIntegral (ord c) * magic + hashInt32 m
+-- > magic = 0xdeadbeef
+--
+-- Where hashInt32 works just as hashInt shown above.
+--
+-- Knuth argues that repeated multiplication by the golden ratio
+-- will minimize gaps in the hash space, and thus it's a good choice
+-- for combining together multiple keys to form one.
+--
+-- Here we know that individual characters c are often small, and this
+-- produces frequent collisions if we use ord c alone. A
+-- particular problem are the shorter low ASCII and ISO-8859-1
+-- character strings. We pre-multiply by a magic twiddle factor to
+-- obtain a good distribution. In fact, given the following test: