Re: Using variable names in a macro

[Narendra Joshi]

Michael Heerdegen <michael_heerdegen@web.de> writes:

> Narendra Joshi <narendraj9@gmail.com> writes:
>
>> Can you share an example please? :)
>
> If you want to go with anonymous functions, `letrec' is perfect here
> (`cl-labels' would work as well and avoid the need to `funcall'):
>
> #+begin_src emacs-lisp
> ;; -*- lexical-binding: t -*-
>
> (defun my-do-when-idle (f g interval)
>   "Call F when idle for INTERVAL seconds and then G when there is activity."
>   (letrec ((run-timer-fun (lambda () (run-with-idle-timer
>                                  interval nil
>                                  (lambda ()
>                                    (funcall f)
>                                    (add-hook 'post-command-hook 
> activity-fun)))))
>            (activity-fun (lambda ()
>                            (remove-hook 'post-command-hook activity-fun)
>                            (funcall g)
>                            (funcall run-timer-fun))))
>     (funcall run-timer-fun)))
> #+end_src
Perfect. `letrec` makes it very simple! :) Thanks a lot! :)
>
> I've changed the order in the `activity-fun' to run `remove-hook' first,
> so that you get a sane behavior when running G gives an error.
Makes sense! :)

Best,
-- 
Narendra Joshi