generic-mode: Keywords also highlight with an underscore

generic-mode: Keywords also highlight with an underscore

["O. Wölfelschneider"]

Hi group!

Say I did:

(define-generic-mode 'fnord-mode
   nil
   (list "fnord" "foobar")
   nil
   (list "\\.fnord")
   (list 'turn-on-font-lock))

This mode will then highlight the keywords fnord and foobar.

However, it will also highlight _fnord, foobar_ and so on.

I do not want the keyword to highlight if it has an
underscore attached to it.

How can I get rid of this behaviour?

(Emacs 21.4 that comes with debian sarge, also an older
20.7.1 on windows)

Thanks!
  Olav

Re: generic-mode: Keywords also highlight with an underscore

[rgb]

> Say I did:
>
> (define-generic-mode 'fnord-mode
>    nil
>    (list "fnord" "foobar")
>    nil
>    (list "\\.fnord")
>    (list 'turn-on-font-lock))
>
> This mode will then highlight the keywords fnord and foobar.
>
> However, it will also highlight _fnord, foobar_ and so on.
>
> I do not want the keyword to highlight if it has an
> underscore attached to it.
>
> How can I get rid of this behaviour?
>

By far the easiest way is to give the underscore character
word syntax.  Which is exactly how I avoid the problem in
tacl-mode.

    (modify-syntax-entry ?\_ "w" st)

Other than that you probably need to use font-lock-list
rather than keyword-list so you can build your own
regexp that excludes the characters that shouldn't
be allowed to touch the keywords.

Re: generic-mode: Keywords also highlight with an underscore

["O. Wölfelschneider"]

rgb wrote:
>     (modify-syntax-entry ?\_ "w" st)

Great, that works.
Since I didn't know what to put in for st, I defined

(defun syntax-table-for-fnord() (modify-syntax-entry ?\_ "w"))

and have this called on start of fnord-mode.

However, I'd rather have this fix globally. Is there
a global syntax table that I can use for st in my .emacs?

Thanks a lot!
Olav

Re: generic-mode: Keywords also highlight with an underscore

[rgb]

> >     (modify-syntax-entry ?\_ "w" st)
>
> Great, that works.
> Since I didn't know what to put in for st, I defined
>
> (defun syntax-table-for-fnord() (modify-syntax-entry ?\_ "w"))
>
I believe that you would use this to modify a modes table
from a mode hook.

(modify-syntax-entry ?\_ "w" (syntax-table))

When writing a mode I usually see it done like this:

(defvar tal-mode-syntax-table
  (let ((st (make-syntax-table)))
    (modify-syntax-entry ?\n ">" st)
     ... <zillion other lines snipped>
    (modify-syntax-entry ?\_ "w" st)
    (modify-syntax-entry ?\{ "." st)
    (modify-syntax-entry ?\| "." st)
    (modify-syntax-entry ?\} "." st)
    st)
  "Syntax table for `tal-mode'.")

Then this is in the tal-mode function:

  (set-syntax-table tal-mode-syntax-table)


> However, I'd rather have this fix globally. Is there
> a global syntax table that I can use for st in my .emacs?
>
I've never tried to modify the global map so I'm not
sure this is correct but looks to me like it should be.

(modify-syntax-entry ?\_ "w" (standard-syntax-table))