Re: Mysterious fontification/C++ context issue

[Stefan Monnier]

>> The docstring doesn't mention anything about it.  And really, when
>> defun-prompt-regexp is nil, then beginning-of-defun considers that "defun
>> starts when there is a char with open-parenthesis syntax at the beginning of
>> a line".  So if open-paren-in-column-0-is-defun-start is nil, it's hard to
>> figure out what should be considered as a defun start.
>> 
>> It's kind of like saying "I won't tell you what it is, I'll just tell you
>> that it's not what you think".

> We could explicitly document that this situation (defun-prompt-regexp
> and o-p-i-c-0-i-d-s both nil) means "figure it out using
> syntactically", i.e. using ppss as Alan implemented.

We could, but I'm very much not in favor since it makes o-p-i-c-0-i-d-s more
important than it deserves and it's very unclear that this behavior is of
any use to beginning-of-defun.  It seems to only be "useful" in the case
where you actually wanted to use syntax-ppss and
syntax-ppss-toplevel-pos instead.

> * Updating the relevant docstrings to say what defun-prompt-regexp and
>   o-p-i-c-0-i-d-s both nil means.

I think the current docstring is quite clear.

> * Updating the Elisp manual, and mentioning that such a combination
>   can be slow.

> * Checking in Martin's optimization to Alan's code.

> * Setting o-p-i-c-0-i-d-s to t for cc mode.

* revert the change and live with the resulting occasional problems for now
  (problems which have existed for ever anyway).


-- Stefan