Re: How to fontify region according to mode

[Lennart Borgman <lennart.borgman@gmail.com>]

On Sat, Aug 14, 2010 at 7:14 PM, Dan Davison <davison@stats.ox.ac.uk> wrote:
> I want to write a function to fontify a region according to a certain
> mode, and I tried the following tactic (see function below):
>
> - get the value of `font-lock-defaults' from a buffer in the target mode
>  and bind it inside a let
> - bind a bunch of other font-lock variable names to stop them being
>  overwritten
> - call `font-lock-set-defaults'
> - call `font-lock-fontify-region'
>
> It didn't seem to work. Could someone suggest how to alter this so that
> it works, or is this approach fundamentally flawed?
>
> (defun dan/font-lock-fontify-region (mode start end)
>  (let ((font-lock-defaults
>         (with-temp-buffer
>           (funcall mode)
>           font-lock-defaults))
>        font-lock-keywords
>        font-lock-keywords-only
>        font-lock-keywords-case-fold-search
>        font-lock-syntax-table
>        font-lock-beginning-of-syntax-function)
>    (font-lock-set-defaults)
>    (font-lock-fontify-region start end)))
>
>
> I want the rest of the buffer to remain unaltered and, for now, I'm not
> looking for a solution involving mumamo/multi-mode etc.


If you want to see how it works then look in mumamo.el. I think you
will find the answers to your questions there. (But why do you want to
reinvent the wheel? What is the purpose?)