Re: (progn (top-level) A B C)

Re: (progn (top-level) A B C)

[A Soare]

> I do not think you can do it directly, but maybe you can use a timer?
> 
> (run-with-idle-timer 0 nil (lambda()

Thanks, I will check. Another method that I found is

(unwind-protect
    (prog1
        (message "x")
      (top-level))
  (message "a")
  (message "b"))


By the way, this code returns "Back to top level." . BAD.

x
a
b
Back to top level.

What is the definition of prog1? It should return the first argument. It seems that in this case the 1st argument is lost.

This is a BUG in prog1... I think that prog2, progn give the same bug... That is?


Does somebody else knows another methods? Let us make all of you that know a list of methods here for this problem, please...


Trying to solve a bug in the E debugger I asked myself this problem...

Alin Soare.



> Message du 14/02/07 à 17h38
> De : "Lennart Borgman (gmail)" <lennart.borgman@gmail.com>
> A : alinsoar@voila.fr
> Copie à : "Emacs Help [help-gnu-emacs]" <help-gnu-emacs@gnu.org>
> Objet : Re: (progn (top-level) A B C)
> 
> A Soare wrote:
> > Hello,
> > 
> > Can somebody tell me how you write a code to execute the followiung commands in the order t-l A B C:
> > 
> > (top-level)
> > (A ...)
> > (B ...)
> > (C ...) ?
> 
> 
> I do not think you can do it directly, but maybe you can use a timer?
> 
> (run-with-idle-timer 0 nil (lambda()
>                               (message "a")(sit-for 1)
>                               (message "b")(sit-for 1)
>                               (message "c")(sit-for 1)
>                               ))
> (top-level)
> 
>

Re: (progn (top-level) A B C)

[Andreas Schwab]

A Soare <alinsoar@voila.fr> writes:

> Thanks, I will check. Another method that I found is
>
> (unwind-protect
>     (prog1
>         (message "x")
>       (top-level))
>   (message "a")
>   (message "b"))
>
>
> By the way, this code returns "Back to top level." . BAD.

It does not return anything.

> x
> a
> b
> Back to top level.
>
> What is the definition of prog1? It should return the first argument. It seems that in this case the 1st argument is lost.

This is not a bug. (top-level) throws to 'top-level, thus (prog1 ...) is
never finished.  unwind-protect only returns a value if the body completes
normally.  Otherwise it does not return anything, rather execution is
transferred directly to the receiving exception handler after executing
the unwind forms.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
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