Re: font-lock-syntactic-keywords obsolet?

[Dmitry Gutov]

On 06/21/2016 05:40 PM, Alan Mackenzie wrote:

> Yes, no, and N/A, respectively.  Try out this raw string support,
> sometime.

Here's some results: a performance degradation example, and a way to 
break CC Mode, apparently.

First, paste this near the top of xdisp.c (I did it after the big 
comment and before the header includes, but this is probably not too 
important):

const char* s1 = R"foo(
Hello
World
)foo";

and switch to c++-mode.

1) Delete the last double-quote, then type it again. Deletion is 
noticeably slow (even though bearably so: feels like 0.5 sec), restoring 
it is faster.

2) Delete the first double-quote, then type it again. Get this backtrace:

Debugger entered--Lisp error: (wrong-type-argument integer-or-marker-p nil)
  c-after-change-re-mark-raw-strings(15101 15102 0)
  #[(fn) "	\n#\207" [fn beg end old-len] 
4](c-after-change-re-mark-raw-strings)
  mapc(#[(fn) "	\n#\207" [fn beg end old-len] 4] 
(c-extend-font-lock-region-for-macros c-after-change-re-mark-raw-strings 
c-neutralize-syntax-in-and-mark-CPP c-restore-<>-properties 
c-change-expand-fl-region))
  c-after-change(15101 15102 0)
  self-insert-command(1)
  funcall-interactively(self-insert-command 1)
  call-interactively(self-insert-command nil nil)
  command-execute(self-insert-command)

This scenario is really the first thing I've tried.