From: Mark H Weaver <mhw@netris.org>
To: ludo@gnu.org (Ludovic Courtès)
Cc: guile-devel@gnu.org
Subject: Re: The empty string and other empty strings
Date: Tue, 10 Jan 2012 07:27:00 -0500 [thread overview]
Message-ID: <8739bnagkr.fsf@netris.org> (raw)
In-Reply-To: <874nw353a4.fsf_-_@gnu.org> ("Ludovic \=\?utf-8\?Q\?Court\=C3\=A8s\?\= \=\?utf-8\?Q\?\=22's\?\= message of "Tue, 10 Jan 2012 10:13:07 +0100")
ludo@gnu.org (Ludovic Courtès) writes:
> Anyway, it seems that before, you couldn’t get any encoding error for
> scm_from_stringn ("", "SOME-ENCODING"), whereas now you can.
Good point. I just committed a change to avoid this.
> A related question: can we have both narrow and wide empty strings?
I see one place where a wide null string could be created: vm-i-loader.c
line 115, within the "load-wide-string" vm instruction, calls
`scm_i_make_wide_string' but never calls `scm_i_try_narrow_string' as is
usually done. I guess this might be because "load-wide-string" is
normally never used for strings that contain only Latin 1 characters.
Other than that, I don't see how a wide null string could exist outside
of temporaries, although it's hard to entirely rule out the possibility.
All of the code paths try to avoid using wide strings unless a wide
character is actually present.
If a wide null string did exist, I don't see what harm it would cause,
besides causing failure if `scm_i_string_chars' applied to it.
Thanks,
Mark
next prev parent reply other threads:[~2012-01-10 12:27 UTC|newest]
Thread overview: 117+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-03 4:08 What's wrong with this? Bruce Korb
2012-01-03 15:03 ` Mike Gran
2012-01-03 16:26 ` Guile: " Bruce Korb
2012-01-03 16:30 ` Mike Gran
2012-01-03 22:24 ` Ludovic Courtès
2012-01-03 23:15 ` Bruce Korb
2012-01-03 23:33 ` Ludovic Courtès
2012-01-04 0:55 ` Bruce Korb
2012-01-04 3:12 ` Noah Lavine
2012-01-04 17:37 ` bytevector -- was: " Bruce Korb
2012-01-04 21:17 ` Ludovic Courtès
2012-01-04 22:36 ` Bruce Korb
2012-01-05 0:01 ` Ludovic Courtès
2012-01-05 18:36 ` non-reproduction of initial issue -- was: " Bruce Korb
2012-01-05 18:50 ` Mark H Weaver
2012-01-04 12:19 ` Ian Price
2012-01-04 17:16 ` Bruce Korb
2012-01-04 17:21 ` Andy Wingo
2012-01-04 17:39 ` David Kastrup
2012-01-04 21:52 ` Ian Price
2012-01-04 22:18 ` Bruce Korb
2012-01-04 23:22 ` Mike Gran
2012-01-04 23:59 ` Mark H Weaver
2012-01-05 17:22 ` Bruce Korb
2012-01-05 18:13 ` Mark H Weaver
2012-01-05 19:02 ` Mark H Weaver
2012-01-05 20:24 ` David Kastrup
2012-01-05 22:42 ` Mark H Weaver
2012-01-06 1:02 ` Mike Gran
2012-01-06 1:41 ` Mark H Weaver
2012-01-06 2:38 ` Noah Lavine
2012-01-06 13:37 ` Mike Gran
2012-01-06 14:11 ` David Kastrup
2012-01-06 18:13 ` Mark H Weaver
2012-01-06 19:06 ` Bruce Korb
2012-01-06 19:19 ` David Kastrup
2012-01-06 20:03 ` Mark H Weaver
2012-01-07 16:13 ` Mark H Weaver
2012-01-07 17:35 ` mutable interfaces - was: " Bruce Korb
2012-01-07 17:47 ` David Kastrup
2012-01-07 18:30 ` Mark H Weaver
2012-01-07 18:55 ` Mark H Weaver
2012-01-06 22:23 ` Guile BUG: " Bruce Korb
2012-01-06 23:11 ` Mark H Weaver
2012-01-06 23:35 ` Andy Wingo
2012-01-06 23:41 ` Bruce Korb
2012-01-07 15:00 ` Mark H Weaver
2012-01-07 15:27 ` Bruce Korb
2012-01-07 16:38 ` Mark H Weaver
2012-01-07 17:39 ` Bruce Korb
2012-01-09 15:41 ` Mark H Weaver
2012-01-09 17:27 ` Bruce Korb
2012-01-09 18:32 ` Andy Wingo
2012-01-09 19:48 ` Bruce Korb
2012-01-07 15:47 ` David Kastrup
2012-01-07 17:07 ` Mark H Weaver
2012-01-07 14:35 ` Mark H Weaver
2012-01-07 15:20 ` Mike Gran
2012-01-07 22:25 ` Ludovic Courtès
2012-01-10 9:13 ` The empty string and other empty strings Ludovic Courtès
2012-01-10 11:28 ` Mike Gran
2012-01-10 13:03 ` Mark H Weaver
2012-01-10 13:09 ` Mike Gran
2012-01-10 15:41 ` Mark H Weaver
2012-01-10 15:48 ` David Kastrup
2012-01-10 16:15 ` Mark H Weaver
2012-01-12 22:33 ` Ludovic Courtès
2012-01-13 9:27 ` David Kastrup
2012-01-13 16:39 ` Mark H Weaver
2012-01-13 17:36 ` David Kastrup
2012-01-16 8:26 ` Marijn
2012-01-16 8:47 ` David Kastrup
2012-01-20 21:31 ` Andy Wingo
2012-01-10 14:10 ` David Kastrup
2012-01-10 12:21 ` Mike Gran
2012-01-10 12:27 ` Mark H Weaver [this message]
2012-01-10 16:34 ` Ludovic Courtès
2012-01-10 17:04 ` David Kastrup
2012-01-06 23:28 ` Guile BUG: What's wrong with this? Bruce Korb
2012-01-07 20:57 ` Guile: " Ian Price
2012-01-08 5:05 ` Mark H Weaver
2012-01-06 9:23 ` David Kastrup
2012-01-05 7:22 ` David Kastrup
2012-01-04 22:46 ` Ludovic Courtès
2012-01-04 3:04 ` Mike Gran
2012-01-04 9:35 ` nalaginrut
2012-01-04 9:41 ` David Kastrup
2012-01-04 21:07 ` Ludovic Courtès
2012-01-04 10:03 ` Mark H Weaver
2012-01-04 14:29 ` Mike Gran
2012-01-04 14:45 ` David Kastrup
2012-01-04 16:47 ` Andy Wingo
2012-01-04 17:14 ` David Kastrup
2012-01-04 17:32 ` Andy Wingo
2012-01-04 17:49 ` David Kastrup
2012-01-04 18:09 ` Andy Wingo
2012-01-04 17:30 ` Bruce Korb
2012-01-04 17:44 ` David Kastrup
2012-01-04 18:26 ` Ian Price
2012-01-04 18:48 ` Mark H Weaver
2012-01-04 19:29 ` Bruce Korb
2012-01-04 20:20 ` David Kastrup
2012-01-04 23:19 ` Mark H Weaver
2012-01-04 23:28 ` Bruce Korb
2012-01-07 15:43 ` Fixed string corruption bugs (was Guile: What's wrong with this?) Mark H Weaver
2012-01-07 16:19 ` Fixed string corruption bugs Andy Wingo
2012-01-04 18:31 ` Guile: What's wrong with this? Mark H Weaver
2012-01-04 18:43 ` Andy Wingo
2012-01-04 19:29 ` Mark H Weaver
2012-01-04 19:43 ` Andy Wingo
2012-01-04 20:08 ` Bruce Korb
2012-01-04 20:14 ` David Kastrup
2012-01-04 20:56 ` Andy Wingo
2012-01-04 21:30 ` Bruce Korb
2012-01-04 17:19 ` Mark H Weaver
2012-01-05 4:24 ` Mark H Weaver
2012-01-04 22:37 ` Ludovic Courtès
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