Re: Question about dired-do-find-regexp and xref-collect-matches

[Dmitry Gutov]

Hi Eric,

On 10.07.2019 2:18, Eric Abrahamsen wrote:
> A while ago I switched to the fish shell, which I generally like better
> than bash.

I also like fish, a lot. I don't use it inside Emacs, though.

> While poking around I also noticed that dired-do-find-regexp calls
> xref-collect-matches once per marked file. That means a full find+grep
> call for each file, when a single find+grep call (or even just a single
> grep call!) would do the trick.

That sounds like a bug report material. Up until now I figured a few 
extra shell process calls wouldn't matter, but maybe they can.

Just how many files are you marking in the given example?

> The search hits are collected as:
>
> (mapcan
>   (lambda (file)
>     (xref-collect-matches regexp "*" file
>                           (and (file-directory-p file)
>                                ignores)))
>   files)
>
> But the second argument to `xref-collect-matches' can be a
> space-separated string of file names -- wouldn't it be easier just to
> call `xref-collect-matches' once?

Not exactly. That FILES argument is something different (a list of globs).

Overall, this shouldn't be too hard to fix. Could you send your response 
to the bug tracker as a new report?