[Ur] urweb-mode speed issues

[Adam Chlipala]

Chris Casinghino wrote:
> The urweb emacs mode seems to be very slow on large files.  In
> particular, scrolling down is very slow in basics.urs.  It starts off
> at a reasonable speed, but as I scroll further down into the file I
> have to wait longer and longer for each additional page - several
> seconds for each page down by the time I hit line 400.  After the text
> has been displayed into the buffer once, scrolling up and down is
> quick (until I close emacs).
>
> Is anyone else experiencing this?  Admittedly, my laptop is 3 years
> old, but something must be wrong here.  I am running emacs 23 on
> ubuntu 10.04.
>    

Yes, there is something very slow in the colorization code, as a result 
of my Emacs inexperience.  I think I've confirmed this by turning off 
font-lock-mode, which removes the noticeable delays.

Patches from more emacs-savvy folks would be much appreciated.