* Re: [Emacs-diffs] master ef75c3b: Optimize `file-equal-p' and `file-in-directory-p' in Tramp
[not found] ` <E1ZwSwD-0005m3-U8@vcs.savannah.gnu.org>
@ 2015-11-11 14:40 ` Stefan Monnier
2015-11-11 15:38 ` Michael Albinus
0 siblings, 1 reply; 4+ messages in thread
From: Stefan Monnier @ 2015-11-11 14:40 UTC (permalink / raw)
To: emacs-devel; +Cc: Michael Albinus
> + (when (string-equal
> + (file-remote-p (expand-file-name filename1))
> + (file-remote-p (expand-file-name filename2)))
The above args to string-equal aren't always strings: why not use
`equal' instead?
(string-equal nil "nil") is non-nil, so I think the code will work
correctly but only because file-remote-p should hopefully never return
"nil".
Stefan
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Emacs-diffs] master ef75c3b: Optimize `file-equal-p' and `file-in-directory-p' in Tramp
2015-11-11 14:40 ` [Emacs-diffs] master ef75c3b: Optimize `file-equal-p' and `file-in-directory-p' in Tramp Stefan Monnier
@ 2015-11-11 15:38 ` Michael Albinus
2015-11-11 16:07 ` Stefan Monnier
0 siblings, 1 reply; 4+ messages in thread
From: Michael Albinus @ 2015-11-11 15:38 UTC (permalink / raw)
To: Stefan Monnier; +Cc: emacs-devel
Stefan Monnier <monnier@iro.umontreal.ca> writes:
>> + (when (string-equal
>> + (file-remote-p (expand-file-name filename1))
>> + (file-remote-p (expand-file-name filename2)))
>
> The above args to string-equal aren't always strings: why not use
> `equal' instead?
> (string-equal nil "nil") is non-nil, so I think the code will work
> correctly but only because file-remote-p should hopefully never return
> "nil".
file-remote-p never returns "nil". It returns either the remote prefix
of a file name (a string), or nil.
> Stefan
Best regards, Michael.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Emacs-diffs] master ef75c3b: Optimize `file-equal-p' and `file-in-directory-p' in Tramp
2015-11-11 15:38 ` Michael Albinus
@ 2015-11-11 16:07 ` Stefan Monnier
2015-11-11 16:46 ` Michael Albinus
0 siblings, 1 reply; 4+ messages in thread
From: Stefan Monnier @ 2015-11-11 16:07 UTC (permalink / raw)
To: Michael Albinus; +Cc: emacs-devel
>>> + (when (string-equal
>>> + (file-remote-p (expand-file-name filename1))
>>> + (file-remote-p (expand-file-name filename2)))
>>
>> The above args to string-equal aren't always strings: why not use
>> `equal' instead?
>> (string-equal nil "nil") is non-nil, so I think the code will work
>> correctly but only because file-remote-p should hopefully never return
>> "nil".
> file-remote-p never returns "nil".
That's what I meant by "I think the code will work correctly but only
because ...".
> It returns either the remote prefix of a file name (a string), or nil.
Can you really prove that "the remote prefix of a file name" will never
be "nil"? Remember: your proof can only assume that one of filename1 or
filename2 is a Tramp file name (the other can be anything at all,
possibly matching any weird file-name-handler).
I think rather than try to prove it, it's easier to use `equal' and move on.
Stefan
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Emacs-diffs] master ef75c3b: Optimize `file-equal-p' and `file-in-directory-p' in Tramp
2015-11-11 16:07 ` Stefan Monnier
@ 2015-11-11 16:46 ` Michael Albinus
0 siblings, 0 replies; 4+ messages in thread
From: Michael Albinus @ 2015-11-11 16:46 UTC (permalink / raw)
To: Stefan Monnier; +Cc: emacs-devel
Stefan Monnier <monnier@iro.umontreal.ca> writes:
>> It returns either the remote prefix of a file name (a string), or nil.
>
> Can you really prove that "the remote prefix of a file name" will never
> be "nil"? Remember: your proof can only assume that one of filename1 or
> filename2 is a Tramp file name (the other can be anything at all,
> possibly matching any weird file-name-handler).
A Tramp file name will never return "nil" for the remote prefix. If the
other file is plagued by a weird file name handler which returns "nil":
no problem. string-equal returns nil, and that's what's expected.
> I think rather than try to prove it, it's easier to use `equal' and move on.
If you feel better, change it. I don't care too much about.
> Stefan
Best regards, Michael.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2015-11-11 14:40 ` [Emacs-diffs] master ef75c3b: Optimize `file-equal-p' and `file-in-directory-p' in Tramp Stefan Monnier
2015-11-11 15:38 ` Michael Albinus
2015-11-11 16:07 ` Stefan Monnier
2015-11-11 16:46 ` Michael Albinus
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