How easy to create new major mode?

How easy to create new major mode?

[Tim Morley (remove vegetable for email address)]

Hi all.

I believe the solution to my current emacs challenge will be to create a new
major mode, albeit a very simple one. I'd be grateful for
   (a) confirmation that this is the way to attack the problem (or failing
that, a better suggestion)
and assuming this is indeed the case
   (b) guidance/URLs/code samples to help me put together what I need.

What I would like to achieve is a customised system of syntax colouration,
to help with reading through hundreds of lines of text. All I need is for
lines starting with the word User to come up in, say, magenta, and lines
starting with System in blue, with a default text colour of grey. (There are
carriage-returns at the end of each line of text, so my keywords will always
be at the beginning of a new line).

I've had a look at the .el files for the various existing modes, but as an
absolute novice in Lisp, I'm not sure which are the relevant bits to
cut-out-and-keep.

Any pointers will be very gratefully received. Cheers all.


Tim Morley

Re: How easy to create new major mode?

[Stefan Monnier <foo@acm.com>]

>>>>> "Tim" == Tim Morley \(remove vegetable for email address\) <Tim> writes:
> I believe the solution to my current emacs challenge will be to create a new
> major mode, albeit a very simple one. I'd be grateful for

I recommend http://www.emacswiki.org/cgi-bin/wiki.pl?SampleMode


        Stefan

Re: How easy to create new major mode?

[Brendan Halpin]

"Tim Morley \(remove vegetable for email address\)" <tim@teamlog.turnip.com> writes:

> I believe the solution to my current emacs challenge will be to create a new
> major mode, albeit a very simple one. I'd be grateful for
>    (a) confirmation that this is the way to attack the problem (or failing
> that, a better suggestion)
> and assuming this is indeed the case
>    (b) guidance/URLs/code samples to help me put together what I need.
> 
> What I would like to achieve is a customised system of syntax colouration,
> to help with reading through hundreds of lines of text. All I need is for
> lines starting with the word User to come up in, say, magenta, and lines
> starting with System in blue, with a default text colour of grey. (There are
> carriage-returns at the end of each line of text, so my keywords will always
> be at the beginning of a new line).

A major mode might be a neat way to do it, but isn't necessary.
Your requirements are relatively simple, and putting overlays on
top of regexps might be an easy way to do it.

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; not really tested
(make-face 'tm-user)
(set-face-foreground 'tm-user "green")
(set-face-background 'tm-user "black")


(make-face 'tm-system)
(set-face-foreground 'tm-system "red")
(set-face-background 'tm-system "grey90")

(defun tm-clear-overlays ()
  (dolist (x (append (car (overlay-lists)) 
                     (cdr (overlay-lists))))
    (if (memq (overlay-get x 'face)
              '(tm-user tm-system))
        (delete-overlay x))))

(defun tm-set-overlays ()
  (tm-clear-overlays)
  (save-excursion
    (while (re-search-forward "^User:[^\n]+" nil t)
      (overlay-put (make-overlay (match-beginning 0)
                                 (match-end 0)) 'face 'tm-user)))
  (save-excursion
    (while (re-search-forward "^System:[^\n]+" nil t)
      (overlay-put (make-overlay (match-beginning 0)
                                 (match-end 0)) 'face 'tm-system))))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

Obviously, a major mode will scale better than this, but for a
simple application this will do.

Brendan
-- 
Brendan Halpin,  Department of Sociology,   University of Limerick,  Ireland
Tel: w +353-61-213147 f +353-61-202569 h +353-61-390476;  Room F2-025 x 3147
<mailto:brendan.halpin@ul.ie>        <http://wivenhoe.staff8.ul.ie/~brendan>

Re: How easy to create new major mode?

[Tim Morley (remove vegetable for email address)]

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Thanks aplenty Brendan -- I've copied your function into my .emacs, pasted
in a few extra regexps to make it really pretty, and learnt a bit of Lisp at
the same time.  :o)  Cheers for that.

Just one thing -- I had to add `(interactive)' immediately after the two
(defun .......) lines [just blindly following the other functions already in
my .emacs] to be able to access the functions; at least, I can now do it
with M-x tm-set-overlays; maybe I just didn't know how to get at it
before...?

Anyway, thanks for your help.


Tim



"Brendan Halpin" <brendan.halpin@ul.ie> a écrit dans le message news:
m3lm115n10.fsf@wivenhoe.staff8.ul.ie...
> "Tim Morley \(remove vegetable for email address\)"
<tim@teamlog.turnip.com> writes:
>
> > I believe the solution to my current emacs challenge will be to create a
new
> > major mode, albeit a very simple one. I'd be grateful for
> >    (a) confirmation that this is the way to attack the problem (or
failing
> > that, a better suggestion)
> > and assuming this is indeed the case
> >    (b) guidance/URLs/code samples to help me put together what I need.
> >
> > What I would like to achieve is a customised system of syntax
colouration,
> > to help with reading through hundreds of lines of text. All I need is
for
> > lines starting with the word User to come up in, say, magenta, and lines
> > starting with System in blue, with a default text colour of grey. (There
are
> > carriage-returns at the end of each line of text, so my keywords will
always
> > be at the beginning of a new line).
>
> A major mode might be a neat way to do it, but isn't necessary.
> Your requirements are relatively simple, and putting overlays on
> top of regexps might be an easy way to do it.
>
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> ;; not really tested
> (make-face 'tm-user)
> (set-face-foreground 'tm-user "green")
> (set-face-background 'tm-user "black")
>
>
> (make-face 'tm-system)
> (set-face-foreground 'tm-system "red")
> (set-face-background 'tm-system "grey90")
>
> (defun tm-clear-overlays ()
>   (dolist (x (append (car (overlay-lists))
>                      (cdr (overlay-lists))))
>     (if (memq (overlay-get x 'face)
>               '(tm-user tm-system))
>         (delete-overlay x))))
>
> (defun tm-set-overlays ()
>   (tm-clear-overlays)
>   (save-excursion
>     (while (re-search-forward "^User:[^\n]+" nil t)
>       (overlay-put (make-overlay (match-beginning 0)
>                                  (match-end 0)) 'face 'tm-user)))
>   (save-excursion
>     (while (re-search-forward "^System:[^\n]+" nil t)
>       (overlay-put (make-overlay (match-beginning 0)
>                                  (match-end 0)) 'face 'tm-system))))
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
>
> Obviously, a major mode will scale better than this, but for a
> simple application this will do.
>
> Brendan
> --
> Brendan Halpin,  Department of Sociology,   University of Limerick,
Ireland
> Tel: w +353-61-213147 f +353-61-202569 h +353-61-390476;  Room F2-025 x
3147
> <mailto:brendan.halpin@ul.ie>
<http://wivenhoe.staff8.ul.ie/~brendan>

Re: How easy to create new major mode?

[Colin Marquardt]

"Tim Morley \(remove vegetable for email address\)" <tim@teamlog.turnip.com> writes:

> Hi all.
>
> I believe the solution to my current emacs challenge will be to create a new
> major mode, albeit a very simple one. I'd be grateful for
>    (a) confirmation that this is the way to attack the problem (or failing
> that, a better suggestion)
> and assuming this is indeed the case
>    (b) guidance/URLs/code samples to help me put together what I need.
>
> What I would like to achieve is a customised system of syntax colouration,
> to help with reading through hundreds of lines of text. All I need is for
> lines starting with the word User to come up in, say, magenta, and lines
> starting with System in blue, with a default text colour of grey. (There are
> carriage-returns at the end of each line of text, so my keywords will always
> be at the beginning of a new line).

Funny, I just answered a similar question over in comp.emacs in
<k8z7kclmfxv.fsf@slsf86.stgl.sel.alcatel.de>.

I'll just copy my article:

Pat Colbeck <pcolbeck@bashq.org> writes:

> Can anyone point me at some good references for writing a basic syntax
> highlighting mode. I need to write some for highlighting some debug
> outputs from routers etc. I am not a programer so the simpler the better
> :)
>
> So far I have found:
>
> http://www.emacswiki.org/cgi-bin/wiki.pl?CategoryCode

This also points you to
http://www.emacswiki.org/cgi-bin/wiki.pl?ModeTutorial 
which should help if you want to write a full mode.

To stay really simplistic, you could try highlight-regexp like this:

(defun cm-colorize ()
  "Colorize stuff. Uses highlight-regexp aka hi-lock-face-buffer from hi-lock.el."
  (interactive)
  ;;(highlight-regexp REGEXP &optional FACE)
  (highlight-regexp "ERROR" 'hi-red-b)
  (highlight-regexp "FIXME" 'hi-red-b)
  (highlight-regexp "ANN:" 'hi-pink)
  (highlight-regexp "success" 'hi-green)
  (highlight-regexp "\\bcomplete\\b" 'hi-green)
  (highlight-regexp "Testing [A-Za-z0-9_]+" 'hi-blue)
)

Or use that here as a starting point:

(defun my-highlight-fixme ()
  (interactive)
  (font-lock-mode 1)
  (font-lock-add-keywords
   nil '(("\\<\\(FIXME\\|TODO\\|XXX\\|!!!\\)" 1 font-lock-warning-face prepend))))
(add-hook 'c-mode-common-hook 'my-highlight-fixme)
(add-hook 'cperl-mode-hook 'my-highlight-fixme)
(add-hook 'emacs-lisp-mode-hook 'my-highlight-fixme)
(add-hook 'vhdl-mode-hook 'my-highlight-fixme)

HTH,
  Colin

Re: How easy to create new major mode?

[Friedrich Dominicus]

"Tim Morley \(remove vegetable for email address\)" <tim@teamlog.turnip.com> writes:

> Hi all.
> 
> I believe the solution to my current emacs challenge will be to create a new
> major mode, albeit a very simple one. I'd be grateful for
>    (a) confirmation that this is the way to attack the problem (or failing
> that, a better suggestion)
> and assuming this is indeed the case
>    (b) guidance/URLs/code samples to help me put together what I
> need.
Well if you are interested in Emacs Lisp programming, have a look at
"Writing GNU Emacs extensions", there is a chapter in it on how to
develop you own major mode. 


> 
> What I would like to achieve is a customised system of syntax colouration,
> to help with reading through hundreds of lines of text. All I need is for
> lines starting with the word User to come up in, say, magenta, and lines
> starting with System in blue, with a default text colour of grey. (There are
> carriage-returns at the end of each line of text, so my keywords will always
> be at the beginning of a new line).
No for such simple thing an own major mode is over-kill.
Check the documentation for font-face, This will be enough for what
you are planning to do. 

Regards
Friedrich