Re: regexp font-lock highlighting

[martin rudalics <rudalics@gmx.at>]

 >     Moreover I don't think that anything is "broken" in the following:
 >
 > 	    ;; Underline innermost grouping, so that you can more easily see what
 > 	    ;; belongs together.  2005-05-12: Font-lock can go into an
 > 	    ;; unbreakable endless loop on this -- something's broken.
 > 	    ;;("[\\][\\][(]\\(?:\\?:\\)?\\(\\(?:[^\\\"]+\\|[\\]\\(?:[^\\]\\|[\\][^(]\\)\\)+?\\)[\\][\\][)]"
 > 	     ;;1 'underline prepend)
 >
 >     I believe that `font-lock-fontify-keywords-region' starts backtracking
 >     and this can take hours in more complicated cases.
 >
 > That sounds like "broken" to me.  Whether it takes hours, or forever,
 > either way Font Lock mode will be very unpleasant to use.
 >
 >       Anyway, regexps are
 >     not suited to handle this.  If you are willing to pay for two additional
 >     buffer-local variables such as
 >
 > I believe you, and it is ok to add local variables for this purpose.
 > (Their names should start with `font-lock-' so that people understand
 > what they are for.  Or perhaps with `lisp-fl-' since they are
 > specifically for Lisp mode.)
 >

Note that I only fixed the endless looping behavior here.  My code is
not suitable when you use a support mode like jit-lock and change the
delimiters of regexp groups.  You would have to refontify text manually
which is not very desirable.  I'll try to handle this in a more
user-friendly way.