Re: Better way to make sure external command exists in the system?

[Emanuel Berg]

Jean Louis wrote:

>>> Now it is:
>>>
>>> (defvar image-default-resize-size "1536")
>>> (defvar image-resize-sizes '("1536" "1024" "800" "1200" "640"))
>> 
>> Well, the width of a computer image is not a string but
>> an integer.
>
> Maybe yes, maybe not, but it does not matter neither for
> human or computer. Human sees the number at completion.

...

>>> Maybe it works with numbers, but now I changed it to
>>> completing-read, maybe that is why I placed it as strings.
>> 
>> Don't do that, data should be in its natural, sound state,
>> then it is up to functions and/or users who use it to
>> convert it to fit their purposes. And the better everything
>> is, the less of that is required.
>
> In general yes, but in this specific case, who cares

... >:[

> This does not work:
>
> (completing-read "Number: " '(1 2 3))
>
> This works:
>
> (completing-read "Number: " '("1" "2" "3"))
>
> Now you get it

... >:[

> why they are strings in the completion list? They are not
> strings for the underlying function `image-resize' but only
> for the completion candidates.

Use a set function

  (cl-map 'list #'number-to-string '(1 2 3)) ; ("1" "2" "3")

>> Yes, compare:
>> 
>> (interactive
>>   `(,(string-to-number
>>        (completing-read "Digit: " '("11" "12" "13") nil t "11"))))
>
> That would mean if I change candidates list I would actually
> need to change the function. Not practical.

... just unheard of

>>>> And, no need for globals if they are only used here.
>>>> Use let* for that as well.
>>>
>>> Which globals?
>> 
>> The two global variables.
>
> I would not know which...

I give up.

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