[Haskell-cafe] Re: Stream processors

[Peter Simons]

K P SCHUPKE writes:

 > This is the interface I came up with (and its fairly efficient):
 > data IList a i e = ICons i i (a i e) (IList a i e) | INil

Isn't that an interface for doing fast I/O rather than for
writing stream processors? If I look at the consumer:

 > wc :: List l Word8 => l Word8 -> Char -> Int -> Int -> Int 
 >    -> (Int,Int,Int)

I don't see how the IList data type would help writing the
wc function. Where is the advantage over 

  data CountingState = ST !Bool !Int !Int !Int
  wc :: Char -> CountingState -> CountingState

...?

Peter