RE: customize-apropos-options takes forever...

[Drew Adams]

    >  M-x customize-apropos-options RET RET
    >
    > On Emacs 22, this takes quite a while. On Emacs 20, it finishes very
    > quickly.
    >
    > Emacs 22 has a lot more options, of course, and more faces
    > and buttons and such, but it still feels like things are less
    > efficient now. In emacs -Q, there are 4698 lines in the buffer
    > in Emacs 22; in Emacs 20, there are 2333 lines (about half).
    > But Emacs 22 takes *far* longer than twice as long.

    I took some time to look into this.

Thanks Chong.

    For M-x customize-apropos RET RET:

    Emacs 22 takes 140.04 seconds to make 1904 entries, i.e. 13.6 / second.
    Emacs 21 takes 76.38  seconds to make 1048 entries, i.e. 13.7 / second.

    Conclusion: >>>> This Is Not A Bug <<<<

I was comparing Emacs 20, not Emacs 21. Perhaps the same difference in
performance exists between 20 and 21. Believe me, there is a marked
difference between 20 and 22. Again, I know that Customize in 22 is a lot
fancier than in 20, and it does more behind the scene, so degraded
performance is not a full measure of usefulness - Customize in 22 is better
than in 20, and I don't want to go backward here.

    I think the reason you thought Emacs 22 is slower is that the echo
    area tells you how much % of the job is done.  Obviously, 1% of 1904
    entries takes longer to do than 1% of 1048 entries, giving the
    illusion that Emacs 22 is progressing more slowly.

No, I was not paying attention to the echo area. I was simply waiting for
the buffer to appear (!) and for my keyboard and mouse to come back to me
from Never-Never Land.

    In the reality, of course, it's silly to do M-x customize-apropos with
    no regexp in the first place.

Agreed, but people do silly things sometimes. Searching among all options is
a reasonable thing to want to do, but I agree that there are other ways to
do that.

apropos-variable is good for getting descriptions of all user options (but
not faces) - but it doesn't show you the values. And edit-options is quick
and useful for getting both descriptions and values, but it is deprecated.