fnv-1a.hs

import Data.Bits (xor)
import Data.Char (ord)
import Data.Word (Word8, Word32)

fnv1a :: [Word8] -> Word32
fnv1a = foldl (\h x -> (h `xor` fromIntegral x) * 0x01000193) 0x811C9DC5

-- Test vectors from https://tools.ietf.org/html/draft-eastlake-fnv-05#page-15
test = and
  [ fnv1a []                    == 0x811c9dc5
  , fnv1a (map ord8 "a")        == 0xe40c292c
  , fnv1a (map ord8 "foobar")   == 0xbf9cf968

  , fnv1a (map ord8 "\0")       == 0x050c5d1f
  , fnv1a (map ord8 "a\0")      == 0x2b24d044
  , fnv1a (map ord8 "foobar\0") == 0x0c1c9eb8
  ]

ord8 = fromIntegral . ord