bug#1727: 23.0.60; char syntax for non-breaking space

bug#1727: 23.0.60; char syntax for non-breaking space

[Richard M Stallman]

Please write in English if possible, because the Emacs maintainers
usually do not have translators to read other languages for them.

Your bug report will be posted to the emacs-pretest-bug@gnu.org mailing list.

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

When I type C-x = at a non-breaking space, it tells me that it
has code 160, hex a0.  But when I execute (insert "\xa0"),
it inserts something that displays as `\240' and for which C-x =
displays this:

   Char:   (4194208, #o17777640, #x3fffa0, raw-byte) point=198 of 211 (93%) column=5

Is that a bug?  It seems quite confusing to me.
I am unable to figure out what I should write in Lisp code
to represent non-breaking space.  This isn't documented.

Perhaps \N should give non-breaking space.


If Emacs crashed, and you have the Emacs process in the gdb debugger,
please include the output from the following gdb commands:
    `bt full' and `xbacktrace'.
If you would like to further debug the crash, please read the file
/home/rms/emacs-cvs/etc/DEBUG for instructions.


In GNU Emacs 23.0.60.15 (mipsel-unknown-linux-gnu, GTK+ Version 2.12.11)
 of 2008-12-22 on lemote-yeeloong
configured using `configure  'CFLAGS=-O0 -g -Wno-pointer-sign' 'mipsel-unknown-linux-gnu' 'build_alias=mipsel-unknown-linux-gnu' 'host_alias=mipsel-unknown-linux-gnu' 'target_alias=mipsel-unknown-linux-gnu''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Major mode: Mail

Minor modes in effect:
  gpm-mouse-mode: t
  tooltip-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t
  abbrev-mode: t

Recent input:
SPC C-y C-x C-x " C-e " ESC b ESC b ESC f C-f C-f [ 
. ] C-e ) RET C-a C-u C-p ESC f ESC f ESC f ESC f ESC 
f ESC f C-f ESC f C-f C-x = C-x b RET C-x b RET C-a 
ESC : ESC p ESC f ESC f ESC f ESC f DEL DEL DEL x a 
0 C-e RET C-x C-g ESC : ESC p C-k C-y C-g C-x b * s 
c TAB RET C-n C-u C-y C-f ESC d ESC d ESC d i n s e 
r t C-e C-a C-k ESC : C-y RET C-h i m e m a c s ESC 
DEL e l i s p RET m t r i n g ESC DEL l i s p SPC d 
a t RET m s t r i n g SPC t y DEL DEL DEL TAB C-g C-v 
m e d i t ESC DEL p r o g r TAB RET C-u C-n C-u C-n 
C-u C-n C-n RET C-u C-u C-n C-u C-n C-u C-n C-n C-n 
RET C-v p SPC SPC SPC C-x b RET C-n ESC SPC DEL \ DEL 
C-x b P TAB RET C-p C-p C-p ESC b C-b C-b C-x = C-x 
b RET C-q 2 4 0 RET C-p C-e C-b C-b C-x = C-n C-a C-x 
= C-n ESC : ESC p C-g C-x 4 m e m a c s - d e ESC DEL 
ESC DEL e m a c s - o r e t e s t ESC b C-d o ESC x 
r e p o r t SPC e a DEL m n a c DEL DEL DEL a c s SPC 
TAB \ DEL RET

Recent messages:
Char:   (160, #o240, #xa0, file ...) point=1554 of 2188 (71%) column=39
1848 (#o3470, #x738)
Quit
Mark set
nil
Composing main Info directory...done
Quit
Char:   (160, #o240, #xa0, file ...) point=1628 of 2188 (74%) column=47
Char:   (4194208, #o17777640, #x3fffa0, raw-byte) point=198 of 201 (98%) column=5
Char:   (160, #o240, #xa0, file ...) point=201 of 201 (100%) column=0
Quit

bug#1727: 23.0.60; char syntax for non-breaking space

[martin rudalics]

When I do

(insert ?\u00a0)

I get for that character

---
         character:   (160, #o240, #xa0)
preferred charset: unicode (Unicode (ISO10646))
        code point: 0xA0
            syntax: . 	which means: punctuation
          category: b:Arabic j:Japanese l:Latin
       buffer code: #xC2 #xA0
         file code: not encodable by coding system undecided-unix
           display: by this font (glyph code)
     uniscribe:-outline-Courier New-normal-normal-normal-mono-13-*-*-*-c-*-iso10646-1 (#x03)
    hardcoded face: nobreak-space

Character code properties: customize what to show
   name: NO-BREAK SPACE
   old-name: NON-BREAKING SPACE
   general-category: Zs (Separator, Space)
   decomposition: (noBreak 32) (noBreak ' ')
---

but I don't know whether that's of any use here :-(

martin

bug#1727: 23.0.60; char syntax for non-breaking space

[Eli Zaretskii]

> From: Richard M Stallman <rms@gnu.org>
> Date: Mon, 29 Dec 2008 05:23:31 -0500
> Cc: 
> 
> When I type C-x = at a non-breaking space, it tells me that it
> has code 160, hex a0.  But when I execute (insert "\xa0"),
> it inserts something that displays as `\240'

(insert #xa0) works for me.

bug#1727: 23.0.60; char syntax for non-breaking space

[Richard M Stallman]

    > When I type C-x = at a non-breaking space, it tells me that it
    > has code 160, hex a0.  But when I execute (insert "\xa0"),
    > it inserts something that displays as `\240'

    (insert #xa0) works for me.

Also:

    (insert ?\u00a0)

Could you document this in the Lisp Manual?
And the general principles so one can understand
why this is so?

bug#1727: 23.0.60; char syntax for non-breaking space

[Eli Zaretskii]

> From: Richard M Stallman <rms@gnu.org>
> CC: 1727@emacsbugs.donarmstrong.com, emacs-pretest-bug@gnu.org,
> 	bug-gnu-emacs@gnu.org
> Date: Tue, 30 Dec 2008 17:26:50 -0500
> 
>     > When I type C-x = at a non-breaking space, it tells me that it
>     > has code 160, hex a0.  But when I execute (insert "\xa0"),
>     > it inserts something that displays as `\240'
> 
>     (insert #xa0) works for me.
> 
> Also:
> 
>     (insert ?\u00a0)
> 
> Could you document this in the Lisp Manual?

Did you mean to document (insert #xa0), or the fact that "\xa0"
inserts a raw byte (or both)?

bug#1727: 23.0.60; char syntax for non-breaking space

[Richard M Stallman]

    > Could you document this in the Lisp Manual?

    Did you mean to document (insert #xa0), or the fact that "\xa0"
    inserts a raw byte (or both)?

It's not a matter of documenting this one specific example.
The Lisp Manual should give sufficient information to
figure out what happens with these two characters.
Right now it doesn't.

bug#1727: 23.0.60; char syntax for non-breaking space

[Noam Postavsky]

The discrepancy between char and string escaping syntax is currently
documented under "Non-ASCII Characters in Strings":

   You can also use hexadecimal escape sequences (‘\xN’) and octal
escape sequences (‘\N’) in string constants.  *But beware:* If a string
constant contains hexadecimal or octal escape sequences, and these
escape sequences all specify unibyte characters (i.e., less than 256),
and there are no other literal non-ASCII characters or Unicode-style
escape sequences in the string, then Emacs automatically assumes that it
is a unibyte string.  That is to say, it assumes that all non-ASCII
characters occurring in the string are 8-bit raw bytes.