From: oscarfv@telefonica.net (Óscar Fuentes)
To: Eli Zaretskii <eliz@gnu.org>
Cc: michael_heerdegen@web.de, 23902@debbugs.gnu.org
Subject: bug#23902: 25.1.50; Strange warning on string-collate-equalp's docstring
Date: Sat, 09 Jul 2016 23:36:37 +0200 [thread overview]
Message-ID: <87eg72cx3u.fsf@wanadoo.es> (raw)
In-Reply-To: <83shvig21e.fsf@gnu.org> (Eli Zaretskii's message of "Sat, 09 Jul 2016 20:21:49 +0300")
Eli Zaretskii <eliz@gnu.org> writes:
> But they can reason this way instead:
>
> "I want to compare two file names.
> Collation is a way to compare strings, for example the man page for
> strcoll says the function returns zero if one string is equal to the
> other.
> And Emacs just learned how to use collation to compare strings, it
> has this great new function string-collate-equalp.
> Therefore, let's use string-collate-equalp for comparing two file
> names."
This implies that the user knows about string comparisons with collation
but he is a complete ignoramus about file systems. A bit unrealistic.
Anyway, saying "don't use this for comparing file names" is cryptic.
Mentioning file-equal-p would be helpful if you insist on mentioning
file names on the docstring of string-collate-equalp.
>> And suppose I have two strings, and want to know if they are equal,
>> respecting my locale's convention about characters that are not
>> literally identical, but have the same meaning. I should use
>> string-collate-equalp for this. This is true whether the strings
>> represent the names of elephants in a zoo, or files on a disk.
>
> And that is exactly the fallacy that the note warns against. Because
> filesystems don't compare as equal characters that have the same
> meaning, they compare bytes in a byte stream that is the file name in
> its raw byte form, as recorded on disk.
I think that Glenn is saying that you can compare file names for other
purposes than knowing if they name the same file.
Maybe the user wishes to find a file with a given name, modulo
collation. Search for "tu.txt" and find "tú.txt".
next prev parent reply other threads:[~2016-07-09 21:36 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-05 22:05 bug#23902: 25.1.50; Strange warning on string-collate-equalp's docstring Óscar Fuentes
2016-07-06 14:34 ` Eli Zaretskii
2016-07-06 15:08 ` Michael Heerdegen
2016-07-06 15:28 ` Eli Zaretskii
2016-07-06 15:46 ` Óscar Fuentes
2016-07-06 16:26 ` Eli Zaretskii
2016-07-06 17:44 ` Óscar Fuentes
2016-07-06 18:32 ` Eli Zaretskii
2016-07-09 17:06 ` Glenn Morris
2016-07-09 17:21 ` Eli Zaretskii
2016-07-09 21:36 ` Óscar Fuentes [this message]
2016-07-10 2:40 ` Eli Zaretskii
2016-07-10 3:06 ` Michael Heerdegen
2016-07-10 14:40 ` Eli Zaretskii
2016-07-06 15:55 ` Michael Heerdegen
2016-07-06 16:30 ` Eli Zaretskii
2016-07-06 16:44 ` Michael Heerdegen
2016-07-06 17:18 ` Eli Zaretskii
2016-07-06 22:49 ` Michael Heerdegen
2016-07-07 2:38 ` Eli Zaretskii
2016-07-07 21:52 ` Michael Heerdegen
2016-07-08 10:11 ` Eli Zaretskii
2016-07-08 20:59 ` Michael Heerdegen
2016-07-09 6:52 ` Eli Zaretskii
2016-07-09 17:06 ` Richard Stallman
2016-07-09 22:59 ` Michael Heerdegen
2016-07-06 15:48 ` Glenn Morris
2016-07-06 16:27 ` Eli Zaretskii
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