[Haskell-cafe] convert a list of booleans into Word*

Hello, I haven't found a function in hackage or in the standard library that takes a list of booleans (or a list of 0s and 1s, or a tuple of booleans or 0s and 1s) and outputs a Word8 or Word32. I have written one which seems very inefficient : toWord8 :: [Bool] -> Word8 toWord8 bs = go 0 0 bs where go n r [] = r go n r (b:bs) = go (n+1) (if b then setBit r n else clearBit r n) bs Is there a better way to do this out there ? (If it helps, i'm writting a toy compression algorithm, which outputs binary as lists of booleans, and I'd like to output that in a file). Cheers Paul