Re: [Emacs-diffs] emacs-25 f8208b6: Document the user-level features of the Xref package

[Dmitry Gutov <dgutov@yandex.ru>]

On 01/21/2016 10:00 PM, Eli Zaretskii wrote:

> But a reference includes a file name, doesn't it?  If so, why not
> search through those files?

My core objection is that "find regexp" is not a semantic query. Whereas 
all current xref queries are semantic (i.e. require language analysis 
for best results).

So really want some clear justification, rather than "etags has command 
that does this", and "a user could want this". Without the 
justification, it would be hard to document the new command anyway.

We _couldn't_ just copy "Search through all files listed in tags table" 
from tags-search docstring.

> It probably is for some use cases.  But in others, users might want
> the other kind.

Such as?

>> How about xref-query-replace-in-matches?
>
> Fine with me.

You'd agree that tags-query-replace doesn't require a direct replacement 
then?

> It would be OK for xref-find-regexp to do the same.  Users who want
> the project.el way of doing that can invoke the commands there.  (They
> should probably be documented in the manual.)

We should worry that a user might invoke xref-find-regexp while 
expecting it to behave like project-find-regexp.

Because in most other editors regexp search works more like the latter: 
it's either in the current file, or across the current project.