Re: [Emacs-diffs] trunk r113896: Declare external variables.

Re: [Emacs-diffs] trunk r113896: Declare external variables.

[Stefan Monnier]

> +(eval-when-compile
> +  (defvar directory-sep-char)
> +  (defvar dired-move-to-filename-regexp))

You don't want to "eval" those defvars, since evaluating such a defvar is
mostly a no-op.  So don't put them inside eval-when-compile.


        Stefan

Re: [Emacs-diffs] trunk r113896: Declare external variables.

[Stefan Monnier]

> +  (defvar buffer-name)

This is bad: buffer-name should not be a dynamically-scoped variable.


        Stefan

Re: [Emacs-diffs] trunk r113896: Declare external variables.

[Michael Albinus]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> +(eval-when-compile
>> +  (defvar directory-sep-char)
>> +  (defvar dired-move-to-filename-regexp))
>
> You don't want to "eval" those defvars, since evaluating such a defvar is
> mostly a no-op.  So don't put them inside eval-when-compile.

But it doesn't hurt, does it?

I've written it this way for didactic purposes: it reminds me what it is
good for (byte-compiler!).

>         Stefan

Best regards, Michael.

Re: [Emacs-diffs] trunk r113896: Declare external variables.

[Michael Albinus]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> +  (defvar buffer-name)
>
> This is bad: buffer-name should not be a dynamically-scoped variable.

I don't like it either. It's old code, maybe it came in for whatever
compatibility reason. Don't remember.

Anyway, I've fixed it. It's not the most important part of Tramp, it is
the code reporting Tramp bugs.

>         Stefan

Best regards, Michael.

Re: [Emacs-diffs] trunk r113896: Declare external variables.

[Stefan Monnier]

>>> +(eval-when-compile
>>> +  (defvar directory-sep-char)
>>> +  (defvar dired-move-to-filename-regexp))
>> You don't want to "eval" those defvars, since evaluating such a defvar is
>> mostly a no-op.  So don't put them inside eval-when-compile.
> But it doesn't hurt, does it?

Yes it does.  It actually hides those defvars from the compiler since it
passes the code to `eval' and only passes the result (aka nil) to the
compiler (at least, that's what "eval-when-compile" is supposed to
mean).

It's a bad habit.  The byte-compiler has to do extra work to find those
defvars because of people who write code like that.

Please fix it, so as not to set a bad example,


        Stefan

Re: [Emacs-diffs] trunk r113896: Declare external variables.

[Xue Fuqiao]

On Fri, Aug 16, 2013 at 3:34 PM, Michael Albinus <michael.albinus@gmx.de> wrote:
> Stefan Monnier <monnier@iro.umontreal.ca> writes:
>
>>> +(eval-when-compile
>>> +  (defvar directory-sep-char)
>>> +  (defvar dired-move-to-filename-regexp))
>>
>> You don't want to "eval" those defvars, since evaluating such a defvar is
>> mostly a no-op.  So don't put them inside eval-when-compile.
> I've written it this way for didactic purposes: it reminds me what it is
> good for (byte-compiler!).

Like Stefan said, it burdens the byte-compiler.  You can add some
comments before it.

-- 
Best regards, Xue Fuqiao.
http://www.gnu.org/software/emacs/

Re: [Emacs-diffs] trunk r113896: Declare external variables.

[Michael Albinus]

Stefan Monnier <monnier@IRO.UMontreal.CA> writes:

> Please fix it, so as not to set a bad example,

Done.

>         Stefan

Best regards, Michael.