Re: emacs-27 b46c75b: xref-matches-in-files: Big Tramp speed-up

[Dmitry Gutov <dgutov@yandex.ru>]

Hi Michael,

On 08.01.2020 11:03, Michael Albinus wrote:
> dgutov@yandex.ru (Dmitry Gutov) writes:
> 
>>      xref-matches-in-files: Big Tramp speed-up
>>
>>      * lisp/progmodes/xref.el (xref-matches-in-files):
>>      Greatly improve performance with remote files using Tramp
>>      (bug#34343).
> 
> Thanks. I've made a further improvement in tramp-file-local-name. In
> case NAME is not a Tramp file name, it calls file-local-name now.
> 
> This is to handle use cases like
> 
> (copy-file "/ssh:host:/path/index.html" "https://example.com/path/index.html")
> 
> and more subtle constellations.

Looks like a good change, functionality-wise. But speaking of the change 
below, I'll probably make it, but upon reading the code anybody would 
struggle to guess that this function can handle other local names, not 
just Tramp ones.

>> +      (setq files (mapcar
>> +                   (if (tramp-tramp-file-p dir)
>> +                       #'tramp-file-local-name
>> +                       #'file-local-name)
>> +                   files)))
> 
> You can change this now to
> 
> (setq files (mapcar #'tramp-file-local-name files))

This will shorten the code, and it'll require one fewer declare-function 
in the file.

But allow me to state for the record once more that I'm puzzled by the 
architectural choice we're working with here.