Re: color coding in emacs

[Kevin Rodgers <ihs_4664@yahoo.com>]

Inge wrote:
> hi
> i frequently use a text editor to view some files containing DNA info.
> These are just simply a great number of lines of characters, the
> characters can be A,C,G or T. At the moment I would like to have the
> text color coded, so that each A has one color, each C has another
> color, etc. Since emacs is my favorite editor I wanted to start and see
> if emacs could do it for me.
> However, I am having some difficulties. I thought about creating a new
> major mode and use font-lock. But somehow this doesn't work. The mode
> is recognised, but there is no highlighting or coloring. It does work
> when I manually use hi-lock, but I want the coloring pattern saved
> outside of the file.
> Can anyone tell me if this is at all doable with emacs?

Googling for emacs and dna yields many results, including
http://www.mahalito.net/~harley/elisp/dna-mode.el

> To my .emacs (init) file I added the lines:
> ;; load mode file for fasta mode
> (require 'fasta-mode "/home/ivdberg/customize/fasta-mode.el")
> 
> (add-to-list 'auto-mode-alist '("\\.fa\\'" . fasta-mode))
> (add-to-list 'auto-mode-alist '("\\.fasta\\'" . fasta-mode))
> 
> Fasta-mode.el looks like this:
> ;; fasta-mode.el
> ;; mode inteded for automatic highlighting of fasta files
> 
> (defvar fasta-mode-hook nil)
> 
> (defconst fasta-font-lock-keywords
>   (list
>    '("A" . "Yellow")
>    '("C" . "Green")
>    '("G" . "Blue")
>    '("T" . "Pink"))
> )
> 
> (defun fasta-mode ()
>   "Major mode for highlighting fasta files"
>   (interactive)
>   (kill-all-local-variables)
> 
>   (set (make-local-variable 'font-lock-defaults)
> '(fasta-font-lock-keywords))
> 
>   (setq major-mode 'fasta-mode)
>   (setq mode-name "Fasta")
>   (run-hooks 'fasta-mode-hook)
> )
> 
> (provide 'fasta-mode)

If you want to roll your own, see
http://www.emacswiki.org/cgi-bin/wiki/CreateNewMajorMode

-- 
Kevin Rodgers