Re: A question (confusion) about closure



In article
<7a360a2d-c283-41d4-a4f5-40c176fb4d12@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
viper-2 <visionat@xxxxxxxxxxxxxxxxx> wrote:

On May 6, 12:14 pm, Didier Verna <did...@xxxxxxxxxx> wrote:
viper-2 <visio...@xxxxxxxxxxxxxxxxx> wrote:
On May 6, 3:57 am, Didier Verna <did...@xxxxxxxxxx> wrote:


You have got to be kidding me. I don't see how being dynamically
scoped by default helps you in any way (even in a self-blah-blah editor
in which user options could simply be defined in terms of CL's
defparameter). I don't see how not having lexical scope helps you in any
way either.

Remember that Elisp (a variant of MacLisp) preceded Common Lisp, hence
no CLOS.

Well, RMS worked on the Lisp Machine. He even wrote manuals for it.
He wrote for example the Zmail manual
and co-wrote the Window System Manual. He knew the system very well.
Including Flavors, the object system. He himself wrote an
object-system before there was Flavors. Lisp Machine Lisp was
dynamically scoped with some support for closures.
There was more experience with dynamically scoped Lisps at that time.

The reasons for the use of dynamic scoping have to do with
the design decisions RMS made at the time he decided to rewrite his
TECO based EMACS. I believe (but I could be wrong here) that at the
time, Steele's and Sussman's Scheme project performed poorly with
lexical scoping. Dynamic scoping was thought to be more efficient; see
http://www.gnu.org/software/emacs/emacs-paper.html#SEC17.

Well, the language Elisp could have been changed - if lexical scope
or an object system had been important to the language users.


BTW, what exactly do you mean by "customize and extend [...]" ?

I quoted this from the GNU EMACS Manual http://www.gnu.org/software/emacs/manual/html_mono/emacs.html.

That is how EMACS is commonly referred to by its devotees. Maybe
someone else would clue you in? I'd like to go into more detail, but
I'm completely tied up right now with my law project - the ICC and
suppression of a complaint ( reference Nos. OTP-CR-313/04 and 113-07/
VZ/OO) against the University of Aberdeen (Scotland) for the crime of
apartheid. :-(

I would much prefer to spend my time with mathematics, engineering,
and Lisp.

agt

--
http://lispm.dyndns.org/
.