Font Lock Problems

[Phillip Lord <p.lord@russet.org.uk>]

I'm trying to add support for font lock to a small mode I have
written. 

I am defining the font lock keywords like so...


(defvar language-speak-delimiter " >>>> ")

(font-lock-add-keywords
 'language-speak-mode
 (list (cons language-speak-delimiter font-lock-keyword-face)
       (list (concat "\\(.*\\)" language-speak-delimiter)  1 font-lock-string-face)
       (list (concat language-speak-delimiter "\\(.*\\)") 1 font-lock-type-face)))

(font-lock-add-keywords
 'language-speak-mode
 '(("#.*" 0 font-lock-comment-face)))


This works fine an does what I expect (that is for each line
highlights ">>>>" in one colour, all the text before it in another,
and all the text after it in another). But its does it very
lazily. In fact I have to call "font-lock-fontify-buffer" to get it to
do any fontification at all. 

I'd like it to work a little bit more "on the fly". Can anyone tell me
why it is not?

Phil