From: Stefan Monnier <monnier@iro.umontreal.ca>
To: Jim Porter <jporterbugs@gmail.com>
Cc: emacs-devel@gnu.org
Subject: Re: [RFC] Adding threads to Eshell
Date: Fri, 16 Dec 2022 09:05:11 -0500 [thread overview]
Message-ID: <jwvtu1v4h5x.fsf-monnier+emacs@gnu.org> (raw)
In-Reply-To: <7f4e3357-2c6a-a0d2-cab5-fb641b52877a@gmail.com> (Jim Porter's message of "Thu, 15 Dec 2022 18:37:09 -0800")
> lisp/eshell/esh-cmd.el). This requires a lot of code to handle various Lisp
> special forms, and the allowed forms are fairly limited. It also has a few
> bugs, likely due in part to being written before lexical binding.
I remember discussing this with John the one time we got to meet face to
face and him telling me that he didn't know the concept of
CPS-conversion back then :-)
> However, before I go too far, I wanted to check with other, more
> knowledgeable people: are Emacs threads available on all platforms?
I'll let others answer this part. IIUC the answer is not "yes", but
like you I hope the cases where they're not supported can be simply
swept under the rug.
> A second issue I noticed is that Emacs threads have their own,
> completely separate set of lexical bindings.
Do you really mean *lexical* bindings?
If yes, then I don't understand what you mean (I don't understand how
they could be non-completely separate).
> Is it possible to tell a thread that I want to inherit the bindings
> from wherever I called 'make-thread'?
For statically scoped vars, this should already be the case because the
(lambda ....) you pass to `make-thread` will close over the surrounding
static scopes.
For dynamically scoped vars, you'd have to do it more explicitly.
Lisp Machine Lisp had an operation they called `closure` for that
purpose (they didn't have static scoping at all).
See https://hanshuebner.github.io/lmman/fd-clo.xml
I've had some fun writing an `lml.el` compatibility package which
includes support for that. The corresponding part of the code is:
(oclosure-define (lml-closure
(:predicate lml-closurep))
bindings function)
(defun lml--closure (bindings function)
(oclosure-lambda (lml-closure (bindings bindings)
(function function))
(&rest args)
(cl-progv (mapcar #'car bindings) (mapcar #'cdr bindings)
(apply function args))))
(defun lml-closure (varlist function)
"Create a closure over the dynamic variables in VARLIST."
(lml--closure (mapcar (lambda (v) (cons v (symbol-value v))) varlist)
function))
-- Stefan
next prev parent reply other threads:[~2022-12-16 14:05 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-16 2:37 [RFC] Adding threads to Eshell Jim Porter
2022-12-16 14:05 ` Stefan Monnier [this message]
2022-12-16 20:11 ` Jim Porter
2022-12-17 3:40 ` Stefan Monnier
2022-12-17 5:19 ` Jim Porter
2022-12-16 19:51 ` Eli Zaretskii
2022-12-16 20:25 ` Jim Porter
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=jwvtu1v4h5x.fsf-monnier+emacs@gnu.org \
--to=monnier@iro.umontreal.ca \
--cc=emacs-devel@gnu.org \
--cc=jporterbugs@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this external index
https://git.savannah.gnu.org/cgit/emacs.git
https://git.savannah.gnu.org/cgit/emacs/org-mode.git
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.