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strings draft Tom Lord (22 Jan 2004 05:11 UTC)
Re: strings draft Shiro Kawai (22 Jan 2004 09:46 UTC)
Re: strings draft Tom Lord (22 Jan 2004 17:45 UTC)
Re: strings draft Shiro Kawai (23 Jan 2004 05:03 UTC)
Re: strings draft Tom Lord (24 Jan 2004 00:45 UTC)
Re: strings draft Matthew Dempsky (23 Jan 2004 20:01 UTC)
Re: strings draft Shiro Kawai (24 Jan 2004 03:26 UTC)
Re: strings draft Tom Lord (24 Jan 2004 04:31 UTC)
Re: strings draft Shiro Kawai (24 Jan 2004 04:49 UTC)
Re: strings draft Tom Lord (24 Jan 2004 19:01 UTC)
Re: strings draft Shiro Kawai (24 Jan 2004 22:15 UTC)
Octet vs Char (Re: strings draft) Shiro Kawai (26 Jan 2004 09:58 UTC)
Strings, one last detail. bear (30 Jan 2004 21:12 UTC)
Re: Strings, one last detail. Shiro Kawai (30 Jan 2004 21:43 UTC)
Re: Strings, one last detail. Tom Lord (31 Jan 2004 00:27 UTC)
Re: Strings, one last detail. bear (31 Jan 2004 20:25 UTC)
Re: Strings, one last detail. Tom Lord (31 Jan 2004 20:56 UTC)
Re: Strings, one last detail. bear (01 Feb 2004 02:28 UTC)
Re: Strings, one last detail. Tom Lord (01 Feb 2004 02:58 UTC)
Re: Strings, one last detail. bear (01 Feb 2004 07:53 UTC)
Re: Octet vs Char (Re: strings draft) bear (26 Jan 2004 19:04 UTC)
Re: Octet vs Char (Re: strings draft) Matthew Dempsky (26 Jan 2004 13:13 UTC)
Re: Octet vs Char (Re: strings draft) Matthew Dempsky (26 Jan 2004 13:41 UTC)
Re: Octet vs Char Shiro Kawai (26 Jan 2004 23:38 UTC)
Re: Octet vs Char (Re: strings draft) Ken Dickey (26 Jan 2004 19:40 UTC)
Re: Octet vs Char Shiro Kawai (27 Jan 2004 05:10 UTC)
Re: Octet vs Char Tom Lord (27 Jan 2004 05:37 UTC)
Re: Octet vs Char bear (27 Jan 2004 08:35 UTC)
Re: Octet vs Char (Re: strings draft) bear (27 Jan 2004 08:32 UTC)
Re: Octet vs Char (Re: strings draft) Ken Dickey (27 Jan 2004 06:50 UTC)
Re: Octet vs Char (Re: strings draft) bear (27 Jan 2004 19:06 UTC)
Re: strings draft bear (22 Jan 2004 19:05 UTC)
Re: strings draft Tom Lord (23 Jan 2004 02:06 UTC)
READ-OCTET (Re: strings draft) Shiro Kawai (23 Jan 2004 06:00 UTC)
Re: strings draft bear (23 Jan 2004 07:04 UTC)
Re: strings draft bear (23 Jan 2004 07:20 UTC)
Re: strings draft Tom Lord (24 Jan 2004 00:15 UTC)
Re: strings draft Alex Shinn (26 Jan 2004 01:58 UTC)
Re: strings draft Tom Lord (26 Jan 2004 02:35 UTC)
Re: strings draft bear (26 Jan 2004 02:35 UTC)
Re: strings draft Tom Lord (26 Jan 2004 03:01 UTC)
Re: strings draft Alex Shinn (26 Jan 2004 03:00 UTC)
Re: strings draft Tom Lord (26 Jan 2004 03:27 UTC)
Re: strings draft Shiro Kawai (26 Jan 2004 04:57 UTC)
Re: strings draft Alex Shinn (26 Jan 2004 04:57 UTC)
Re: strings draft tb@xxxxxx (23 Jan 2004 18:48 UTC)
Re: strings draft bear (24 Jan 2004 02:21 UTC)
Re: strings draft tb@xxxxxx (23 Jan 2004 02:09 UTC)
Re: strings draft Tom Lord (23 Jan 2004 02:42 UTC)
Re: strings draft tb@xxxxxx (23 Jan 2004 02:44 UTC)
Re: strings draft Tom Lord (23 Jan 2004 03:07 UTC)
Re: strings draft tb@xxxxxx (23 Jan 2004 03:04 UTC)
Re: strings draft Tom Lord (23 Jan 2004 03:29 UTC)
Re: strings draft tb@xxxxxx (23 Jan 2004 03:42 UTC)
Re: strings draft Alex Shinn (23 Jan 2004 02:34 UTC)
Re: strings draft tb@xxxxxx (23 Jan 2004 02:42 UTC)
Re: strings draft Tom Lord (23 Jan 2004 03:02 UTC)
Re: strings draft Alex Shinn (23 Jan 2004 02:58 UTC)
Re: strings draft tb@xxxxxx (23 Jan 2004 03:13 UTC)
Re: strings draft Alex Shinn (23 Jan 2004 03:18 UTC)
Re: strings draft Bradd W. Szonye (23 Jan 2004 19:31 UTC)
Re: strings draft Alex Shinn (26 Jan 2004 02:21 UTC)
Re: strings draft Bradd W. Szonye (06 Feb 2004 23:30 UTC)
Re: strings draft Bradd W. Szonye (06 Feb 2004 23:33 UTC)
Re: strings draft Alex Shinn (09 Feb 2004 01:45 UTC)
specifying source encoding (Re: strings draft) Shiro Kawai (09 Feb 2004 02:51 UTC)
Re: strings draft Bradd W. Szonye (09 Feb 2004 03:39 UTC)
Re: strings draft tb@xxxxxx (23 Jan 2004 03:12 UTC)
Re: strings draft Alex Shinn (23 Jan 2004 03:28 UTC)
Re: strings draft tb@xxxxxx (23 Jan 2004 03:44 UTC)
Parsing Scheme [was Re: strings draft] Ken Dickey (23 Jan 2004 08:07 UTC)
Re: Parsing Scheme [was Re: strings draft] bear (23 Jan 2004 17:55 UTC)
Re: Parsing Scheme [was Re: strings draft] tb@xxxxxx (23 Jan 2004 18:50 UTC)
Re: Parsing Scheme [was Re: strings draft] Per Bothner (23 Jan 2004 18:56 UTC)
Re: Parsing Scheme [was Re: strings draft] Tom Lord (23 Jan 2004 20:39 UTC)
Re: Parsing Scheme [was Re: strings draft] Per Bothner (23 Jan 2004 20:57 UTC)
Re: Parsing Scheme [was Re: strings draft] Tom Lord (23 Jan 2004 21:57 UTC)
Re: Parsing Scheme [was Re: strings draft] Tom Lord (23 Jan 2004 20:20 UTC)
Re: Parsing Scheme [was Re: strings draft] tb@xxxxxx (23 Jan 2004 21:22 UTC)
Re: Parsing Scheme [was Re: strings draft] Tom Lord (23 Jan 2004 22:52 UTC)
Re: Parsing Scheme [was Re: strings draft] tb@xxxxxx (24 Jan 2004 06:48 UTC)
Re: Parsing Scheme [was Re: strings draft] Tom Lord (24 Jan 2004 18:55 UTC)
Re: Parsing Scheme [was Re: strings draft] tb@xxxxxx (24 Jan 2004 19:34 UTC)
Re: Parsing Scheme [was Re: strings draft] Tom Lord (24 Jan 2004 22:02 UTC)
Re: Parsing Scheme [was Re: strings draft] Ken Dickey (23 Jan 2004 12:53 UTC)
Re: Parsing Scheme [was Re: strings draft] Tom Lord (23 Jan 2004 23:35 UTC)
Re: Parsing Scheme [was Re: strings draft] Ken Dickey (24 Jan 2004 16:10 UTC)
Re: Parsing Scheme [was Re: strings draft] Tom Lord (25 Jan 2004 03:14 UTC)
Re: strings draft Matthew Dempsky (25 Jan 2004 00:00 UTC)
Re: strings draft Tom Lord (25 Jan 2004 07:29 UTC)
Re: strings draft Matthew Dempsky (26 Jan 2004 16:53 UTC)
Re: strings draft Tom Lord (27 Jan 2004 00:44 UTC)

Re: Parsing Scheme [was Re: strings draft] Tom Lord 23 Jan 2004 20:20 UTC


    > From: Ken Dickey <xxxxxx@allvantage.com>

    > Excuse me if the obvious has already been addressed, but..

    > It would be a *bad thing* if in going from one locale to another
    > changed a working Scheme program into a broken Scheme program.

    > So, please be sure that the specification of character and
    > string encoding and of portable Scheme source code defines
    > Scheme source as being locale indepent (by construction).

Do you agree that this is a portable, standard Scheme program?:

	(define i 42)			[a]
        (display i)
        (newline)

What about this next one?   As nearly as I can tell, the formal syntax
in chapter 7 says that this next program is _not_ portable, but the
language in chapters 2 and 6 suggests that that is an unintended
deficiency of chapter 7:

	(DEFINE I 42)			[b]
        (DISPLAY I)
        (NEWLINE)

and if that is legal, is this a portable, standard Scheme program with
equivalent behavior?

	(DEFINE I 42)			[c]
        (display i)
        (newline)

Strictly speaking, R5RS seems to say that [a] is portable, [b] is not,
and among implementations on which [b] and [c] both run, they are not
required to be identical in meaning.  The same strict reading implies
that the following is _not_ a portable Scheme program:

	"H2O"

and that this is permitted:

	(string-ci=? "define" "DEFINE") => #f

I tend to think that R5RS is deficient (relative to the authors'
intentions) in that regard.  These restrictions would make it a real
mess (at best) to try to write a portable Scheme program that could
process Scheme source texts containing identifiers which use any
letters other than #\a..#\z.

For example, I would like this portable, standard program to produce
as output a one-line, portable, standard Scheme expression:

	(display (char-downcase (char-upcase #\i)))
        (newline)

however, the strictest reading of R5RS suggests that it is not
guaranteed to do so.

On the other hand, if [a], [b], and [c] are all portable, equivalent,
standard Scheme programs -- then in Turkish implementations,
CHAR-UPCASE, CHAR-DOWNCASE and friends must behave in a linguistically
odd manner.  I'm not so sure that that's terrible (and my proposals
for R6RS reflect that assessment): those procedures are doomed to
behave in a linguistically odd manner for a substantial number of
reasons, in many other contexts besides Turkish implementations.
While they _may_ behave in linguistically ideal ways in _some_
contexts -- that can not be what they are for.  (Even where they must
behave oddly, they can provide a good _approximation_ of something
linguistically useful.)

Rather, I propose that the standard character procedures be explicitly
related to both the syntax of portable standard Scheme and the syntax
of particular implementations.  For example, R6RS should require that:

	(char-downcase #\I) => #\i

and require that within a given implementation, if:

	(char-alphabetic c) => #t

then

	(display c) (newline)

produces as output a one line expression that consists of a valid
identifier in that implementation.

-t