Re: flet, cl-flet, cl-letf in 24.3

["Andreas Röhler" <andreas.roehler@easy-emacs.de>]

Am 22.04.2013 15:32, schrieb Stefan Monnier:
>> as reported here [5], this documentation does not really tell me what to do
>> if I want to keep relying on the dynamic scoping of flet.  A brief google
>> search [6] leads me to believe that
>
>>      (cl-letf (((symbol-function 'foo) #'(lambda (...) ...))) ...)
>
>> is the suggested solution,
>
> That's the case.
>
>> Does that always have dynamic scope?
>
> How could it not?
>
>> however I wanted to make sure that is the case.
>
> Even better in most cases is:
>
>       (defvar my-enable-foo-advice nil)
>       (defadvice foo (...)
>         (if my-enable-foo-advice ... ...))
>
> and then replace (flet ((foo ...)) ...)
> with (let ((my-enable-foo-advice t)) ...)
>
>
>          Stefan
>
>
>

Hi Stefan,

until now, a let bound variable was easy to use, there was no difficulty wrt global namespace.
 From this would expect some confusion, as a defvar is Emacs-wide. Isn't a defvar setting init-value only at first time?

I.e. if another program already used (defvar my-enable-foo-advice 'my-init-value)
  (defvar my-enable-foo-advice nil) should have not effect.

May someone point me to the thread where that was discussed?

Thanks,

Andreas