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* A question about macro bindings in cl-lib
@ 2013-04-24  8:17 Xue Fuqiao
  2013-04-24  8:56 ` Stephen Berman
  2013-04-24 13:33 ` Stefan Monnier
  0 siblings, 2 replies; 4+ messages in thread
From: Xue Fuqiao @ 2013-04-24  8:17 UTC (permalink / raw)
  To: help-gnu-emacs

In (info "(cl) Macro Bindings"):

  (cl-defmacro my-dolist ((x list) &rest body)
    (let ((var (cl-gensym)))
      (list 'cl-loop 'for var 'on list 'do
            (cl-list* 'cl-symbol-macrolet
                      (list (list x (list 'car var)))
                      body))))
  (setq mylist '(1 2 3 4))
  (my-dolist (x mylist) (cl-incf x))
  mylist
       => (2 3 4 5)

  The `my-dolist' call shown here expands to

  (cl-loop for G1234 on mylist do
        (cl-symbol-macrolet ((x (car G1234)))
          (cl-incf x)))

I understand what this macro does, but what does "G1234" mean here?  (I
have searched the archives, but "No document matching your query".)

--
Best regards, Xue Fuqiao.
http://www.gnu.org/software/emacs/



^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: A question about macro bindings in cl-lib
  2013-04-24  8:17 A question about macro bindings in cl-lib Xue Fuqiao
@ 2013-04-24  8:56 ` Stephen Berman
  2013-04-24 13:33 ` Stefan Monnier
  1 sibling, 0 replies; 4+ messages in thread
From: Stephen Berman @ 2013-04-24  8:56 UTC (permalink / raw)
  To: help-gnu-emacs

On Wed, 24 Apr 2013 16:17:42 +0800 Xue Fuqiao <xfq.free@gmail.com> wrote:

> In (info "(cl) Macro Bindings"):
>
>   (cl-defmacro my-dolist ((x list) &rest body)
>     (let ((var (cl-gensym)))
>       (list 'cl-loop 'for var 'on list 'do
>             (cl-list* 'cl-symbol-macrolet
>                       (list (list x (list 'car var)))
>                       body))))
>   (setq mylist '(1 2 3 4))
>   (my-dolist (x mylist) (cl-incf x))
>   mylist
>        => (2 3 4 5)
>
>   The `my-dolist' call shown here expands to
>
>   (cl-loop for G1234 on mylist do
>         (cl-symbol-macrolet ((x (car G1234)))
>           (cl-incf x)))
>
> I understand what this macro does, but what does "G1234" mean here?

Does the doc string of cl-gensym answer the question for you?  If not,
can you make the question more specific?

Steve Berman




^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: A question about macro bindings in cl-lib
  2013-04-24  8:17 A question about macro bindings in cl-lib Xue Fuqiao
  2013-04-24  8:56 ` Stephen Berman
@ 2013-04-24 13:33 ` Stefan Monnier
  2013-04-24 22:23   ` Xue Fuqiao
  1 sibling, 1 reply; 4+ messages in thread
From: Stefan Monnier @ 2013-04-24 13:33 UTC (permalink / raw)
  To: help-gnu-emacs

> I understand what this macro does, but what does "G1234" mean here?

Nothing, it's a variable whose name was "chosen" by code rather than by
a human.


        Stefan




^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: A question about macro bindings in cl-lib
  2013-04-24 13:33 ` Stefan Monnier
@ 2013-04-24 22:23   ` Xue Fuqiao
  0 siblings, 0 replies; 4+ messages in thread
From: Xue Fuqiao @ 2013-04-24 22:23 UTC (permalink / raw)
  To: help-gnu-emacs

I see, thank you.  I only read the doc string of `cl-loop' and
`cl-symbol-macrolet', and I forgot `cl-gensym'.

--
Best regards, Xue Fuqiao.
http://www.gnu.org/software/emacs/



^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2013-04-24 22:23 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2013-04-24  8:17 A question about macro bindings in cl-lib Xue Fuqiao
2013-04-24  8:56 ` Stephen Berman
2013-04-24 13:33 ` Stefan Monnier
2013-04-24 22:23   ` Xue Fuqiao

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