Re: Is it valid to call isearch-filter-predicate outside isearch?

[Eli Zaretskii <eliz@gnu.org>]

> From: Michael Heerdegen <michael_heerdegen@web.de>
> Cc: emacs-devel@gnu.org
> Date: Thu, 01 Jun 2023 01:17:57 +0200
> 
> Ihor Radchenko <yantar92@posteo.net> writes:
> 
> > The documentation for `isearch-filter-visible' sounds like no side
> > effects are expected:
> >
> >     Predicate to filter hits of Isearch and replace commands.
> >
> >     Isearch hits that don't satisfy the predicate will be skipped.
> >     The value should be a function of two arguments; it will be
> >     called with the positions of the start and the end of the text
> >     matched by Isearch and replace commands.  If this function
> >     returns nil, Isearch and replace commands will continue searching
> >     without stopping at resp. replacing this match.
> >     This function is expected to be careful not to clobber the match data.
> >
> > Either the docstring is not accurate or the implementation of
> > `isearch-range-invisible' is not safe.
> >
> > Am I missing something?
> 
> No.  It has does have side effects that are not documented.

The question is: why do we have to document every possible nit of the
internals?  I still don't think I understand the rationale.  People
who want to know _everything_ about the code should consult the source
code; it's the power of Free Software that they can do it.