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Re: current input & output ports



On Fri, 17 Jun 2005, Alex Shinn wrote:

> How do you propose to give access to stdin and stdout?

Those are two very Unix-centric resources, which is not something I'd
like to see Scheme standardized on except in an interface specifically
to Unix, such as a scsh SRFI.  (Note, by the way, that there are
STANDARD-INPUT-WRITER & STANDARD-INPUT-READER already.)  However, my
complaint is more with the mechanism of a global 'current input port' &
'current output port' afforded special status among the I/O system so
much so as, for example, to destroy useful argument conventions; as I
suggested, there could still be items in the dynamic environment used
for things like terminal interaction ports, or, in a hypothetical Unix
interface, stdin & stdout ports.

(T, for instance, worked in the way I suggest; it still provided access
to stdio ports via settable procedures STANDARD-INPUT & STANDARD-OUTPUT
as well as potentially separate terminal ports with TERMINAL-INPUT &
TERMINAL-OUTPUT.  The I/O-related procedures all required their first
arguments to be ports, except in a couple cases (like PRINT, where the
object being printed could specialize itself); there was no general
'current input port' or 'current output port.')