Re: Idea for syntax-ppss. Is it new? Could it be any good?

[Richard M Stallman]

    > If we have a cache, it might be more efficient to cache the locations
    > where beginnings of defuns were found.

    Actually, it's not because a 10MB file might be composed of
    a single defun.

That case is so rare that it isn't very important.

The benefit of caching beginnings of defuns is that you don't have to
invalidate the cache when there's a change in the buffer.
Subsequent defuns are still valid.