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From: Michael Heerdegen <michael_heerdegen@web.de>
To: npostavs@users.sourceforge.net
Cc: 27016@debbugs.gnu.org, Rafael D Sorkin <rsorkin@perimeterinstitute.ca>
Subject: bug#27016: possible bug in `defsetf'
Date: Tue, 23 May 2017 01:10:09 +0200	[thread overview]
Message-ID: <87fufwmqsu.fsf@drachen> (raw)
In-Reply-To: <87efvgfv4n.fsf@users.sourceforge.net> (npostavs's message of "Mon, 22 May 2017 17:18:32 -0400")

npostavs@users.sourceforge.net writes:

> Oh, right, I see it now.  It happens in 24.4 and later.  I'm not sure
> it's a bug though.  My guess is that the difference is eager
> macroexpansion.  When I compile, then I get the same behaviour with 24.3
> (that's my earliest working Emacs build) as well.

(require 'cl)

(macroexpand-1 (macroexpand-1 (macroexpand-1 '(defsetf foobar setcar))))
==>

#+begin_src emacs-lisp
(gv-define-expander foobar
  (lambda
    (do &rest args)
    (gv--defsetter 'foobar
                   (lambda
                     (val &rest args)
                     `(,'setcar ,@args ,val))
                   do args)))
#+end_src

A comment in the definition of `gv-define-expander' says:

  ;; Use eval-and-compile so the method can be used in the same file as it
  ;; is defined.
  ;; FIXME: Just like byte-compile-macro-environment, we should have something
  ;; like byte-compile-symbolprop-environment so as to handle these things
  ;; cleanly without affecting the running Emacs.

Anyway, the above expands to

(macroexpand-1 (macroexpand-1 (macroexpand-1 (macroexpand-1 '(defsetf foobar setcar)))))
==>

#+begin_src emacs-lisp
(eval-and-compile
  (put 'foobar 'gv-expander
       (lambda
         (do &rest args)
         (gv--defsetter 'foobar
                        (lambda
                          (val &rest args)
                          `(,'setcar ,@args ,val))
                        do args))))
#+end_src

The `put' is evaluated when the `defsetf' macro call is expanded.
That's what's causing the issue.

AFAIK we don't say that `defsetf' is only allowed at top level, so I
would say (without any judgement) that it's a bug.  And it's not limited
to `defsetf' in "cl".


Michael.





  reply	other threads:[~2017-05-22 23:10 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-22  6:39 bug#27016: possible bug in `defsetf' Rafael D Sorkin
2017-05-22 12:11 ` npostavs
2017-05-22 20:25 ` Rafael D Sorkin
2017-05-22 21:18   ` npostavs
2017-05-22 23:10     ` Michael Heerdegen [this message]
2017-05-22 23:23       ` npostavs
2017-05-23  0:45         ` Michael Heerdegen
2017-05-23  0:51           ` npostavs
2017-05-23  1:18             ` Michael Heerdegen
2017-05-22 22:03 ` Rafael D Sorkin
2017-05-22 23:15   ` npostavs
2017-05-24  4:52 ` Rafael D Sorkin
2017-05-24 22:51   ` Michael Heerdegen
2017-05-25  1:50     ` npostavs
2017-05-25  4:59 ` Rafael D Sorkin
2017-05-25  5:01 ` Rafael D Sorkin
2017-05-25 10:38   ` npostavs
2017-05-25 20:26     ` Michael Heerdegen
2017-05-25 20:42       ` Noam Postavsky
2017-05-25 21:31         ` Michael Heerdegen
2017-05-25 23:03           ` npostavs
2017-05-25 23:40             ` Michael Heerdegen
2017-05-26  3:50 ` Stefan Monnier
2017-05-26 22:51   ` npostavs
2017-05-28 20:45     ` Stefan Monnier
2017-07-02 20:47       ` npostavs
2017-07-03 11:25         ` Michael Heerdegen
2017-07-09 20:13           ` npostavs
2017-07-10  0:26             ` Michael Heerdegen
2017-07-11  1:45               ` npostavs
2017-07-11 16:21             ` Stefan Monnier
2017-07-12  0:55               ` npostavs
2017-07-12  2:01                 ` Stefan Monnier
2017-07-13  4:46                   ` npostavs
2017-07-13 14:25                     ` Stefan Monnier
2017-07-14  0:39                       ` npostavs
2017-07-14  3:48                         ` Stefan Monnier
2017-07-14  4:32                           ` Stefan Monnier
2017-07-15 14:51                             ` npostavs
2017-07-16  1:03                               ` Stefan Monnier
2017-08-08  1:18                                 ` npostavs
2017-05-26  5:05 ` Rafael D Sorkin

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