12:26 a.m.
Hi all,
Is there any built-in support for streams of lisp objects? As discussed here:
https://mitpress.mit.edu/sicp/full-text/sicp/book/node70.html
Either in 21.4 or 21.5 may do.
What I mean, is that given any old lisp function that wants a list,
can I hand it a stream at it just works? I suspect the answer is
"no."
--
Johann
I'm not from the internet, I just work there.
_______________________________________________
XEmacs-Beta mailing list
XEmacs-Beta(a)xemacs.org
http://lists.xemacs.org/mailman/listinfo/xemacs-beta
7:04 p.m.
Johann 'Myrkraverk' Oskarsson writes:
Is there any built-in support for streams of lisp objects?
Not as far as I know, certainly if you want processing "as if a list"
(eg, using car and cdr) you need a real list, not a "stream" (whatever
that might be).
_______________________________________________
XEmacs-Beta mailing list
XEmacs-Beta(a)xemacs.org
http://lists.xemacs.org/mailman/listinfo/xemacs-beta
11:23 p.m.
On Mon, Dec 8, 2014 at 12:04 PM, Stephen J. Turnbull <stephen(a)xemacs.org> wrote:
Johann 'Myrkraverk' Oskarsson writes:
> Is there any built-in support for streams of lisp objects?
Not as far as I know, certainly if you want processing "as if a list"
(eg, using car and cdr) you need a real list, not a "stream" (whatever
that might be).
They are lazily computed lists, and no, we don't have any support for
them at present.
--
Jerry James
http://www.jamezone.org/
_______________________________________________
XEmacs-Beta mailing list
XEmacs-Beta(a)xemacs.org
http://lists.xemacs.org/mailman/listinfo/xemacs-beta
1:02 a.m.
Jerry James writes:
On Mon, Dec 8, 2014 at 12:04 PM, Stephen J. Turnbull
<stephen(a)xemacs.org> wrote:
> Johann 'Myrkraverk' Oskarsson writes:
>
> > Is there any built-in support for streams of lisp objects?
>
> Not as far as I know, certainly if you want processing "as if a list"
> (eg, using car and cdr) you need a real list, not a "stream" (whatever
> that might be).
They are lazily computed lists, and no, we don't have any support for
them at present.
But are they really lists? car, nth, listp, plist-get, loop, ... work
on them? "stream" sounds like what Python calls "iterable", i.e.,
basically it supports "pop".
I guess Emacs is just about to add iterators and generators. But they
seem to be very limited, although "unexpectedly useful" according to
one proponent.
_______________________________________________
XEmacs-Beta mailing list
XEmacs-Beta(a)xemacs.org
http://lists.xemacs.org/mailman/listinfo/xemacs-beta
11:44 p.m.
On Tue, Dec 9, 2014 at 6:02 PM, Stephen J. Turnbull <stephen(a)xemacs.org> wrote:
But are they really lists? car, nth, listp, plist-get, loop, ...
work
on them? "stream" sounds like what Python calls "iterable", i.e.,
basically it supports "pop".
RIght, they aren't really lists. They're some kind of data structure
wrapped around a generating function for producing elements of the
list.
I guess Emacs is just about to add iterators and generators. But
they
seem to be very limited, although "unexpectedly useful" according to
one proponent.
Judicious use of this kind of data structure can prevent, or at least
alleviate, memory blowups in some situations, sure. I haven't looked
at the Emacs version. Will have to do so over the Christmas break.
--
Jerry James
http://www.jamezone.org/
_______________________________________________
XEmacs-Beta mailing list
XEmacs-Beta(a)xemacs.org
http://lists.xemacs.org/mailman/listinfo/xemacs-beta
5:59 a.m.
Jerry James writes:
Judicious use of this kind of data structure can prevent, or at
least
alleviate, memory blowups in some situations, sure. I haven't looked
at the Emacs version. Will have to do so over the Christmas break.
I don't think they're in Emacs yet. grep recent emacs-devel for
Daniel Colascione and Artur Malabarba.
_______________________________________________
XEmacs-Beta mailing list
XEmacs-Beta(a)xemacs.org
http://lists.xemacs.org/mailman/listinfo/xemacs-beta
3423
days inactive
3434
days old
5 comments
3 participants
participants (3)
-
Jerry James -
Johann 'Myrkraverk' Oskarsson -
Stephen J. Turnbull