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From: David Kastrup <dak@gnu.org>
To: guile-devel@gnu.org
Subject: Re: The empty string and other empty strings
Date: Tue, 10 Jan 2012 18:04:43 +0100	[thread overview]
Message-ID: <87k44ztro4.fsf@fencepost.gnu.org> (raw)
In-Reply-To: 87mx9vzfcz.fsf@gnu.org

ludo@gnu.org (Ludovic Courtès) writes:

> Hello Mark,
>
> Mark H Weaver <mhw@netris.org> skribis:
>
>> 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.
>
> Cool, thanks for the instant reply and fix!
>
> And thanks to Mike and you for the remainder of the discussion and
> optimizations.
>
> BTW, I just noticed that R5RS uses the phrase “empty strings” (plural)
> in the description of ‘eq?’, which means we’re indeed on the right track.

R5RS is supposed to be a standard, not a guessing game.  When there is
nothing more definitive than splitting hairs in the grammar of the text,
I would prefer sane semantics over probably not even intended
contortions.

"Freshly allocated" for me means that _no_ string operation on
pre-existing objects can make this string different from what it is.
And since there is no way to share the empty contents of an empty string
with other strings, this is true even if every empty string is eq? to
every other one.

-- 
David Kastrup




  reply	other threads:[~2012-01-10 17:04 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
2012-01-10 16:34                                         ` Ludovic Courtès
2012-01-10 17:04                                           ` David Kastrup [this message]
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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