[Larceny-users] (newline port) in err5rs mode

[Jon Wells]

I guess it's me this doesn't seem right but...

***@pow 68% larceny -path . -err5rs
Larceny v0.97 "Funny in the Head" (Aug 19 2009 06:31:24,
precise:Linux:unified)
larceny.heap, built on Wed Aug 19 06:33:35 EDT 2009
ERR5RS mode (no libraries have been imported)

(import (rnrs))
(newline (standard-error-port))

Error: put-char: not an output port #<OUTPUT PORT
*error-output*>
Entering debugger; type "?" for help.
debug> #<EOF>

while

(display "stuff" (standard-error-port))

stuff


jon.

[w***@ccs.neu.edu]

Post by Jon Wells
I guess it's me this doesn't seem right but...
Larceny v0.97 "Funny in the Head" (Aug 19 2009 06:31:24,
precise:Linux:unified)
larceny.heap, built on Wed Aug 19 06:33:35 EDT 2009
ERR5RS mode (no libraries have been imported)

(import (rnrs))
(newline (standard-error-port))

Error: put-char: not an output port #<OUTPUT PORT
*error-output*>
Entering debugger; type "?" for help.
debug> #<EOF>
while

(display "stuff" (standard-error-port))

stuff

Good catch. Neither newline nor display nor put-char should
work with (standard-error-port), which the R6RS requires to be
a "fresh binary output port". I suspect that the usefulness
of display with (standard-error-port) was a transitional matter
to help with the transition to R6RS i/o semantics. With that
transition complete, all textual output operations should raise
exceptions when used with a (standard-error-port) or
(standard-output-port).

The error message was misleading as well. I'll log both bugs
tomorrow.

The portable way to write text to a (standard-output-port) or
(standard-error-port) is to use the transcoded-port procedure

Post by Jon Wells
(define p (transcoded-port (standard-error-port) (native-transcoder)))
(newline p)

Will

[David Rush]

Post by w***@ccs.neu.edu
The portable way to write text to a (standard-output-port) or
(standard-error-port) is to use the transcoded-port procedure

Post by Jon Wells
(define p (transcoded-port (standard-error-port) (native-transcoder)))
(newline p)

presumably CURRENT-OUTPUT-PORT and CURRENT-ERROR-PORT work as in R5?

david

[William D Clinger]

Post by David Rush
presumably CURRENT-OUTPUT-PORT and CURRENT-ERROR-PORT work as in R5?

Yes, but the R5RS doesn't say much about either. In fact, the R5RS
doesn't even mention a current-error-port procedure.

The R6RS requires both (current-output-port) and (current-error-port)
to "return default textual ports". It also says that these ports are
"normally" "associated with standard output, and standard error,
respectively", presumably via some implementation-dependent use of
the transcoded-port procedure or something analogous as illustrated
in my previous message.

Will