Re: non-breaking spaces in view-mode

[Roland Winkler]

On Wed Jan 26 2005 Stefan Monnier wrote:
> > - If EMACS_UNIBYTE is not set, "emacs --no-init-file --no-site-file"
> >   displays non-breaking space as `\240'.
> 
> Are you sure this char is "a non-breaking space"?  It looks like the
> binary ?\240 char, which is in the eight-bit-graphic charset (contrary to
> the "latin-1 non breaking space" char which is in the latin-1 charset and
> whose code inside Emacs 2208).
> 
> What does C-u C-x = say?

Ooops, I am sorry, I mixed it up, it is the other way round.
Does the following make more sense for you?

(I do not know whether I am using the proper terminology for talking
about these things. However, I have a little file that contains this
character `\240'. When I visit this file, the character is displayed
differently depending on whether emacs is in unibyte mode or
multibyte mode.)


- If EMACS_UNIBYTE is set, "emacs --no-init-file --no-site-file"
  displays non-breaking space as `\240'.


  character: Â  (0240, 160, 0xa0)
    charset: eight-bit-graphic (8-bit graphic char (0xA0..0xFF))
 code point: 160
     syntax:    which means: whitespace
buffer code: 0xA0
  file code: 0xA0 (encoded by coding system raw-text-unix)
    display: by this font (glyph code)
     -Misc-Fixed-Medium-R-Normal--20-200-75-75-C-100-ISO8859-1 (0xA0)



- If EMACS_UNIBYTE is not set, "emacs --no-init-file --no-site-file"
  displays non-breaking spaces with a colored backslash and a space.


  character:   (04240, 2208, 0x8a0, U+00A0)
    charset: latin-iso8859-1
             (Right-Hand Part of Latin Alphabet 1 (ISO/IEC 8859-1): ISO-IR-100.)
 code point: 32
     syntax:    which means: whitespace
   category:  :This character counts as a space for indentation purposes.  
             l:Latin  
buffer code: 0x81 0xA0
  file code: 0xA0 (encoded by coding system iso-latin-1-unix)
    display: by this font (glyph code)
     -Misc-Fixed-Medium-R-Normal--20-200-75-75-C-100-ISO8859-1 (0xA0)



...I just noticed another thing:

C-x = sends its output to the echo area

With "emacs --no-init-file --no-site-file --unibyte", the message in
the echo area is

Char: \  (0240, 160, 0xa0, file 0xA0) point=2 of 4 (25%) column 1 

i.e., a colored backslash and a space like in multibyte mode
-- even though the buffer displays `\240'.

This is very confusing!

Roland