Re: How to fontify region according to mode

[Lennart Borgman]

On Sat, Aug 14, 2010 at 8:08 PM, Dan Davison <davison@stats.ox.ac.uk> wrote:
> Lennart Borgman <lennart.borgman@gmail.com> writes:
>
>> 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?)
>
> Hi Lennart,
>
> I was looking at mumamo.el earlier today, but it is 9,101 lines long, so
> I would definitely appreciate some guidance. Note that I don't want
> different regions to be subject to different major modes; I only want to
> change the text properties in a region. That was why I was not using
> mumamo and was attempting the simple approach above. I would certainly
> consider mumamo if I wanted multiple major modes.
>
> Dan


Hi Dan,

I am afraid that what you want actually involves the same problem as
using multiple major modes. Why don't you think so?