Michael Heerdegen <michael_heerdegen@web.de> writes:

> Thierry Volpiatto <thievol@posteo.net> writes:
>
>> Not sure to understand what you want to do here.
>
> Maybe it's easier if I post a patch.  Will try to do this tomorrow.

Yes, not sure to understand what you want to do.

> What I want to do is that `register-read-with-preview' accepts another
> argument, a predicate, that is used to filter the registers to be
> included in the preview.

Why do you need another argument as long as you use `this-command`?
You can use e.g. (pcase this-command ('foo #'foo-p) etc...)
Isn't it?

-- 
Thierry