Re: imenu fails in mode without comment-start-skip defined

[Stefan]

>> Well, it's easy to measure.  Using syntax-ppss instead of the current
>> code makes imenu--make-index-alist 4 times faster when run on
>> simple.el (rather surprisingly).  It's 50% slower than without any
>> check on the context.

>     I.e. the current code with comment-beginning is 6 times slower than
>     before?  Sounds like a very good reason to remove this
>     comment-beginning stuff,

> Maybe so.

> As regards using syntax-ppss, I'm worried that in certain modes it
> would have to scan all the way to the beginning of the buffer over and
> over.  In those modes, it could be hundreds of times slower on a large
> file.

We don't have to worry because we can postpone the use of syntax-ppss to
after the next release.  This "serious problem" we're trying to solve
(i.e. definitions that are commented out) is as old as imenu (and I haven't
seen that many complaints about it), so it can wait one more release.


        Stefan