Hi Mark,

Mark H Weaver <mhw@netris.org> skribis:

> Okay, now I understand.  The problem is that internally, string ports
> are implemented by converting the string into a stream of bytes in the
> string port's encoding, and then the string port reads those bytes.

Exactly.

[...]

> Conceptually, a string port is a textual port, not a binary port.

But not in Guile, where there’s no distinction between textual and
binary ports.  One can write code like:

  scheme@(guile-user)> (define (string->utf16 s)
                         (let ((p (with-fluids ((%default-port-encoding "UTF-16BE"))
                                    (open-input-string s))))
                           (get-bytevector-all p)))
  scheme@(guile-user)> (string->utf16 "hello")
  $4 = #vu8(0 104 0 101 0 108 0 108 0 111)
  scheme@(guile-user)> (use-modules(rnrs bytevectors))
  scheme@(guile-user)> (utf16->string $4)
  $5 = "hello"

> You should be able to hand it an arbitrary string and read those
> characters from it, as described in SRFI-6, without setting
> Guile-specific fluid variables.  Similarly, you should be able to
> write arbitrary characters to a string-output-port.

The SRFI-6 issue could be addressed with: