Re: [PATCH] gnu: guix: Set 'guix-dot-program' emacs variable.

[ludo@gnu.org (Ludovic Courtès)]

Alex Kost <alezost@gmail.com> skribis:

> Ludovic Courtès (2015-10-17 16:34 +0300) wrote:

[...]

>> The docstring should mention that it can be the empty string.
>> Alternately, ‘configure’ could set DOT_USER_PROGRAM to “dot” when it’s
>> not found, which I think is ever preferable.  WDYT?
>
> IMO an empty string is preferable (explained below), so I would like to
> leave it like this (with an improved docstring as you pointed), if you
> don't mind.
>
>>> +(defcustom guix-dot-program
>>> +  (if (string= "" guix-config-dot-program)
>>> +      (executable-find "dot")
>>> +    guix-config-dot-program)
>>
>> Thus here we’d be checking whether ‘guix-config-dot-program’ is an
>> absolute file name.
>
> I think (executable-find "dot") is more reliable than just "dot" which
> may not exist.

Agreed!  I was just saying that an empty string is odd, and that setting
it to ‘dot’ would be aesthetically more pleasing.

So the only different is that the above would become:

  (defcustom guix-dot-program
    (if (absolute-file-name-p guix-config-dot-program)
         guix-config-dot-program
      (executable-find "dot")))

Does it make sense?

Ludo’.