Re: Shrinking the C core

[Christopher Dimech <dimech@gmx.com>]

> Sent: Thursday, August 10, 2023 at 1:19 PM
> From: "Eric S. Raymond" <esr@thyrsus.com>
> To: "Po Lu" <luangruo@yahoo.com>
> Cc: emacs-devel@gnu.org
> Subject: Re: Shrinking the C core
>
> Po Lu <luangruo@yahoo.com>:
> > "Eric S. Raymond" <esr@thyrsus.com> writes:
> >
> > > When I first worked on Emacs code in the 1980s Lisp was already fast
> > > enough, and machine speeds have gone up by something like 10^3 since.
> > > I plain don't believe the "slower" part can be an issue on modern
> > > hardware, not even on tiny SBCs.
> >
> > Can you promise the same, if your changes are not restricted to one or
> > two functions in fileio.c, but instead pervade throughout C source?
>
> Yes, in fact, I can. Because if by some miracle we were able to
> instantly rewrite the entirety of Emacs in Python (which I'm not
> advocating, I chose it because it's the slowest of the major modern
> scripting languages) basic considerations of clocks per second would
> predict it to run a *dead minimum* of two orders of magnitude faster
> than the Emacs of, say, 1990.
>
> And 1990 Emacs was already way fast enough for the human eye and
> brain, which can't even register interface lag of less than 0.17
> seconds (look up the story of Jef Raskin and how he exploited this
> psychophysical fact in the design of the Canon Cat sometime; it's very
> instructive). The human auditory system can perceive finer timeslices,
> down to about 0.02s in skilled musicians, but we're not using elisp
> for audio signal processing.
>
> If you take away nothing else from this conversation, at least get it
> through your head that "more Lisp might make Emacs too slow" is a
> deeply, *deeply* silly idea. It's 2023 and the only ways you can make
> a user-facing program slow enough for response lag to be noticeable
> are disk latency on spinning rust, network round-trips, or operations
> with a superlinear big-O in critical paths.  Mere interpretive overhead
> won't do it.
>
> > Finally, you haven't addressed the remainder of the reasons I itemized.
>
> They were too obvious, describing problems that competent software
> engineers know how to prevent or hedge against, and you addressed me
> as though I were a n00b that just fell off a cabbage truck.

It's a habit of his.  Can't fix without blowing his fuse.

> My earliest contributions to Emacs were done so long ago that they
> predated the systematic Changelog convention; have you heard the
> expression "teaching your grandmother to suck eggs"?  My patience for
> that sort of thing is limited.
> --
> 		<a href="http://www.catb.org/~esr/">Eric S. Raymond</a>
>
>
>
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