Re: comment-filling fixes

[Stefan Monnier]

>> It seems to me a major failing that I have to rely on font-lock (and
>> thus on redisplay being done).  Is there a good reason why the lazy
>> text properties mechanism can't be tarted up (e.g. not just triggered
>> by `buffer-substring') and used to ensure syntax properties are
>> up-to-date for modes that need it?

BTW, here are the reasons why I prefer explicitly calling a function like
(syntax-update-props-upto POS) rather than relying on some new "lazy prop"
at the C level:
- easier, safer.
- faster, since the C primitives won't have to check whether there's
  a lazy-prop at point that needs to be built.  I don't expect that
  syntax-update-props-upto will need to be called from many places in
  the code.
- Building the props from C code might get tricky:
  e.g. when regexp-matching, when are you going to call the elisp code
  to build the syntax-table property that a \s- requests?  From within
  the regexp-engine running arbitrary elisp code is either unsafe or will
  require significant work to make it safe.
- we don't really know yet what we need.  I think the lazy text properties
  that you refer to (i.e. variable buffer-access-fontify-functions) are
  a sadly perfect example of C code implemented before we knew what we
  needed.  It's implemented, documented, and 100% unused.


        Stefan