font-lock-mode limitations

font-lock-mode limitations

[Aurel Buche]

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Hi,

I am working for a company that uses a proprietary Scheme based language
The language has a rich API and its own conventions, so I created a new
major mode but I am struggling with fontification:

I have elisp functions to fetch all documented functions and user-defined
functions from my code and add them properly to font-lock-defaults (using
regexp-opt)

Everything was working fine while I was fetching keywords from a very
limited number of modules. But now I am using more of them and I have
hundreds (maybe thousands) of keywords to highlights. Now that I added more
functions to font-lock-defaults nothing is highlighted anymore.

I really need to add those modules and I definitely require fontification
as I am too used to it.
I don't want to replace keywords with more global regular expressions as it
is really helpful to have keywords highlighted only when they are written
properly

I took a quick glimpse at font-core.el and font-lock.el but I could not
find where the regexp match limitations are set

Do you have a solution or an idea to increase the limits of keywords that
can be matched by font-lock-mode ?

I would be extremely grateful if you can help me

Regards,

Aurélien Buchet

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Re: font-lock-mode limitations

[Stefan Monnier]

> hundreds (maybe thousands) of keywords to highlights.  Now that I added more
> functions to font-lock-defaults nothing is highlighted anymore.

You need to look for the actual error that causes this.
Is there are relevant message in *Messages*?
Maybe M-x jit-lock-debug-mode RET (along with enabling the debugger)
could help as well.

> I took a quick glimpse at font-core.el and font-lock.el but I could not
> find where the regexp match limitations are set

The limits would be in src/regexp.c

BTW, instead of creating a monster regexp, maybe another approach is to
use a simple regexp that matches any identifier in function position
and then look up a table to see what kind of highlighting to apply to it
(IIRC that's what we do in elisp-mode to highlight macro calls
differently from function calls).


        Stefan