RE: [External] : Re: Is it valid to call isearch-filter-predicate outside isearch?

[Drew Adams]

> Do you refer to
>  (add-function :before
>                (local 'isearch-filter-predicate)
>                #'foo)?
> 
> Two reasons:
> 1. I only vaguely understand how this works
> 2. It feels against the interface. If advising this predicate is
>    expected, why not convert it into an abnormal hook?

Caveat: Not really following this thread.  Might be misunderstanding you here.

Wrt #2: A hook doesn't provide the same flexibility as advice, e.g., before, 
after, around.

(Wrt #1: Yes, advice is trickier than hooks.)