From: "Pascal J. Bourguignon" <pjb@informatimago.com>
To: help-gnu-emacs@gnu.org
Subject: Re: Differences between identical strings in Emacs lisp
Date: Tue, 07 Apr 2015 02:10:09 +0200 [thread overview]
Message-ID: <87pp7gu7by.fsf@kuiper.lan.informatimago.com> (raw)
In-Reply-To: mailman.76.1428326518.904.help-gnu-emacs@gnu.org
Jürgen Hartmann <juergen_hartmann_@hotmail.com> writes:
> What is the difference between the string represented by the constant "\xBA"
> and the result of (concat '(#xBA))?
(mapcar 'multibyte-string-p (list "\xBA" (concat '(#xBA))))
--> (nil t)
string-equal (and therefore string=) don't ignore the multibyte property
of a string.
You can use:
(mapcar 'string-as-unibyte (list "\xBA" (concat '(#xBA))))
--> ("\272" "\302\272")
to see the difference.
Now, it's hard to say how to "solve" this problem, basically, you asked
for it: "\xBA" is not a valid way to write a string containing masculine
ordinal.
I guess you could extract back the bytes, and recreate the string
correctly:
(map 'string 'identity (map 'list 'identity "\xBA"))
--> "º"
(string= (map 'string 'identity (map 'list 'identity "\xBA"))
(concat '(#xBA)))
--> t
(On the other hand, one might argue that having both unibyte and
multibyte strings in a lisp implementation is not a good idea, and
there's the opportunity for a big refactoring and simplification).
--
__Pascal Bourguignon__ http://www.informatimago.com/
“The factory of the future will have only two employees, a man and a
dog. The man will be there to feed the dog. The dog will be there to
keep the man from touching the equipment.” -- Carl Bass CEO Autodesk
next parent reply other threads:[~2015-04-07 0:10 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <mailman.76.1428326518.904.help-gnu-emacs@gnu.org>
2015-04-07 0:10 ` Pascal J. Bourguignon [this message]
2015-04-07 13:55 ` [Solved] RE: Differences between identical strings in Emacs lisp Jürgen Hartmann
2015-04-07 14:22 ` Eli Zaretskii
2015-04-07 17:02 ` Jürgen Hartmann
2015-04-07 17:28 ` Eli Zaretskii
2015-04-08 11:01 ` Jürgen Hartmann
2015-04-08 11:59 ` Eli Zaretskii
2015-04-08 12:37 ` Stefan Monnier
2015-04-09 10:38 ` Jürgen Hartmann
2015-04-09 12:32 ` Stefan Monnier
2015-04-09 12:45 ` Eli Zaretskii
2015-04-10 2:35 ` Richard Wordingham
2015-04-10 4:46 ` Stefan Monnier
2015-04-10 12:24 ` Jürgen Hartmann
2015-04-09 10:36 ` Jürgen Hartmann
2015-04-07 18:24 ` Thien-Thi Nguyen
2015-04-09 10:40 ` Jürgen Hartmann
2015-04-06 13:21 Jürgen Hartmann
2015-04-07 21:10 ` Stefan Monnier
2015-04-08 11:02 ` Jürgen Hartmann
2015-04-08 13:44 ` Jürgen Hartmann
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