On 13-Apr-06, at 1:54 PM, Ben Goetter wrote:

> If you separate byte ports from character ports, and separate input
> ports from output ports (at least at the API level), you get an
> easily type-checked interface.  e.g.
>
> open-input-file string [encoding keywords] -> input-character-port
> read-char input-char-port -> character
> open-input-file-raw string -> input-byte-port
> read-byte input-byte-port -> integer

After rereading this part of your message I think I may have
misunderstood you.  Do you mean that the procedure's signatures
should explicit the type of port to indicate the type constraints?
That sounds like a good idea.  I was just following the RnRS
tradition that uses:

   procedure: (read-char port)
   procedure: (write-char char port)

I.e. it does not distinguish input and output ports in the procedure
signatures.

Marc