Extended ascii characters in emacs lisp

Extended ascii characters in emacs lisp

[Richard H Lee]

Hi (again),

I'm using fill-column-indicator.el to set a column margin at column 80 
in emacs. Currently it uses the pipe "|" symbol as the margin character.

I would like to change it one of the extended ascii characters, e.g. the 
solid block / long vertical pipe. I can set it to standard ascii 
characters using:

(setq fci-rule-character ?\101)

e.g. this will set the character to "A". But if I go over 127 into 
extended-ascii, I get:

Invalid read syntax: ?

What is the emacs lisp syntax for extended ascii characters?


Richard

Re: Extended ascii characters in emacs lisp

[Gregory Benjamin]

On Fri, Apr 20, 2012 at 10:37:02PM +0100, Richard H Lee wrote:
> Hi (again),
> 
> I'm using fill-column-indicator.el to set a column margin at column
> 80 in emacs. Currently it uses the pipe "|" symbol as the margin
> character.
> 
> I would like to change it one of the extended ascii characters, e.g.
> the solid block / long vertical pipe. I can set it to standard ascii
> characters using:
> 
> (setq fci-rule-character ?\101)
> 
> e.g. this will set the character to "A". But if I go over 127 into
> extended-ascii, I get:
> 
> Invalid read syntax: ?
> 
> What is the emacs lisp syntax for extended ascii characters?

Instead of extended ascii, I just tried unicode, for example:

(ucs-insert "2503")┃

See Unicode standard 6.1 Box Drawing for other choices.

Best,
Greg

Re: Extended ascii characters in emacs lisp

[PJ Weisberg]

On Fri, Apr 20, 2012 at 2:37 PM, Richard H Lee
<ricardohenrylee@gmail.com> wrote:
> Hi (again),
>
> I'm using fill-column-indicator.el to set a column margin at column 80 in
> emacs. Currently it uses the pipe "|" symbol as the margin character.
>
> I would like to change it one of the extended ascii characters, e.g. the
> solid block / long vertical pipe. I can set it to standard ascii characters
> using:
>
> (setq fci-rule-character ?\101)
>
> e.g. this will set the character to "A". But if I go over 127 into
> extended-ascii, I get:
>
> Invalid read syntax: ?

Actually, it can go up to 511 (a.k.a. "?\777").

See:
http://www.gnu.org/software/emacs/manual/html_node/elisp/General-Escape-Syntax.html

> What is the emacs lisp syntax for extended ascii characters?

Standard way according to the above link is to use the unicode code
point, i.e. "?\u2503".  You might want to just use a character
literal, "?┃", if you don't mind having a ┃ in your source file.

-PJ

Gehm's Corollary to Clark's Law: Any technology distinguishable from
magic is insufficiently advanced.

Re: Extended ascii characters in emacs lisp

[Richard H Lee]

On 21/04/12 00:25, PJ Weisberg wrote:
 > Standard way according to the above link is to use the unicode code
 > point, i.e. "?\u2503".

I used this solution.

What I did not originally realise was that extended ascii is not really 
that well supported in Linux (my os), as it is more of a DOS / Windows 
standard.

Re: Extended ascii characters in emacs lisp

[Jason Rumney]

On Saturday, 21 April 2012 19:49:40 UTC+8, Richard H Lee  wrote:

> What I did not originally realise was that extended ascii is not really 
> that well supported in Linux (my os), as it is more of a DOS / Windows 
> standard.

I guess you mean the graphics drawing characters of codepage-437, which is very definitely a DOS relic.  Even Windows support for it these days is not widespread outside of the command console.

Unicode has these characters and more. See etc/charsets/IBM437.map in the Emacs source distribution (or installed under /usr/share/emacs or similar path), or http://en.wikipedia.org/wiki/Code_page_437 for mappings.