Re: side effects, list sharing [was: `append' vs. `nconc']

[Emanuel Berg <embe8573@student.uu.se>]

Drew Adams <drew.adams@oracle.com> writes:

>> But other then time/space optimization, what would
>> you say is the reason not to play it safe/sane and
>> just return stuff, new stuff if necessary, but
>> instead modify them directly?
>
> You will know it if you see it or when you really
> need it!

Morpheus:

    Unfortunately, no one can be *told* what the
    Matrix is. You have to see it for yourself.

> If you don't see a need for sharing list structure
> then playing it safe/sane is the right approach.

Say that you do a rope-and-wheel mechanism to have
a bathroom door close automatically. As a weight, you
use a bottle. How do you tie the bottle to the rope?
Do you just tie it as a kid would, with random loops
all over, and then pull tight with your muscles? Or do
you look up a professional knot in the BIG BOOK
OF KNOTS?

Just as using advanced Lisp to solve perhaps trivial,
and definitely non-critical problems of Emacs
configuration, it can be seen as hitting the
heavy bag.

If the real deal, whatever that is, ever appears,
you'll be more ready than otherwise. If it doesn't
appear, you at least have a good looking knot, some
cool Elisp, and a fit body!

-- 
underground experts united
http://user.it.uu.se/~embe8573