From: Vladimir Zhbanov <vzhbanov@gmail.com>
To: guile-user@gnu.org
Subject: Self-evaluating function and closure
Date: Wed, 12 Jun 2019 23:29:29 +0300 [thread overview]
Message-ID: <20190612202929.GA20126@newvzh.lokolhoz> (raw)
Greetings,
I have tried almost a textbook example with Guile 2.2.4:
scheme@(guile-user)> (define (function-generator)
(let ((func #f))
(lambda () (set! func (let a () a)) func)))
scheme@(guile-user)> (define x (function-generator))
scheme@(guile-user)> (define y (function-generator))
scheme@(guile-user)> x
$20 = #<procedure f9f9d0 at <unknown port>:562:25 ()>
scheme@(guile-user)> y
$21 = #<procedure bf2660 at <unknown port>:562:25 ()>
scheme@(guile-user)> (x)
$22 = #<procedure a ()>
scheme@(guile-user)> (y)
$23 = #<procedure a ()>
scheme@(guile-user)> (eq? (x) (y))
$24 = #t
The result is unexpected for me, I expected a new self-evaluating
procedure every time I run the function-generator procedure (and
it works differently with Guile 2.0, IIUC, cannot check just now).
AFAICS, Guile creates a toplevel procedure "a" while it should not
do so.
scheme@(guile-user)> a
$25 = #<procedure 109aa90 at <unknown port>:422:25 ()>
Questions:
- Is this a bug?
- Is there a way to work around this (either using the above 'let'
construct or anything else)?
Thanks in advance
--
Vladimir
(λ)επτόν EDA — https://github.com/lepton-eda
next reply other threads:[~2019-06-12 20:29 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-12 20:29 Vladimir Zhbanov [this message]
2019-06-15 19:35 ` Self-evaluating function and closure John Cowan
2019-06-16 0:39 ` Mark H Weaver
2019-06-16 0:36 ` Mark H Weaver
2019-06-16 9:02 ` Vladimir Zhbanov
2019-06-16 10:09 ` Mark H Weaver
2019-06-17 8:03 ` Vladimir Zhbanov
2019-06-16 9:47 ` Mark H Weaver
2019-06-16 10:21 ` Thomas Morley
2019-06-16 10:32 ` Mark H Weaver
2019-06-16 10:42 ` Thomas Morley
2019-06-16 11:29 ` Mark H Weaver
2019-06-17 8:48 ` Vladimir Zhbanov
2019-06-17 14:21 ` Mark H Weaver
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
List information: https://www.gnu.org/software/guile/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190612202929.GA20126@newvzh.lokolhoz \
--to=vzhbanov@gmail.com \
--cc=guile-user@gnu.org \
/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.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).