Re: [PATCH v9 03/11] ref-filter: implement an `align` atom

[Eric Sunshine <sunshine@sunshineco.com>]

On Sun, Aug 9, 2015 at 2:55 AM, Karthik Nayak <karthik.188@gmail.com> wrote:
> On Sun, Aug 9, 2015 at 9:12 AM, Eric Sunshine <sunshine@sunshineco.com> wrote:
>> On Sat, Aug 8, 2015 at 2:35 AM, Karthik Nayak <karthik.188@gmail.com> wrote:
>>> On Fri, Aug 7, 2015 at 8:57 AM, Eric Sunshine <sunshine@sunshineco.com> wrote:
>>>> On Wed, Aug 5, 2015 at 2:54 PM, Karthik Nayak <karthik.188@gmail.com> wrote:
>>>>> +               else if (align->align_type == ALIGN_MIDDLE) {
>>>>> +                       int right = (align->align_value - buf_len)/2;
>>>>> +                       strbuf_addf(final, "%*s%-*s", align->align_value - right + len,
>>>>> +                                   value->buf, right, "");
>>>>
>>>> An aesthetic aside: When (align_value - buf_len) is an odd number,
>>>> this implementation favors placing more whitespace to the left of the
>>>> string, and less to the right. In practice, this often tends to look a
>>>> bit more awkward than the inverse of placing more whitespace to the
>>>> right, and less to the left (but that again is subjective).
>>>
>>> I know that, maybe we could add an additional padding to even out the value
>>> given?
>>
>> I don't understand your question. I was merely suggesting (purely
>> subjectively), for the "odd length" case, putting the extra space
>> after the centered text rather than before it. For instance:
>>
>>     int left = (align->align_value - buf_len) / 2;
>>     strbuf_addf(final, "%*s%-*s", left, "",
>>         align->align_value - left + len, value->buf);
>>
>> or any similar variation which would give the same result.
>
> I get this could be done, what I was asking was, Consider given a alignment
> width of 25 would be better to make that 26 so that we have even padding on
> both sides. But I don't like the adding of manipulating user given data.

I thought you might be asking that, but wasn't certain. I do agree
with your conclusion that second-guessing the user is a bad idea, and
that you should give the user exactly what was requested.

>> That raises another question. Why are 'struct ref_formatting_state',
>> 'struct align', 'struct atom_value', etc. defined in ref-filter.h at
>> all? Aren't those private implementation details of ref-filter.c, or
>> do you expect other code to be using them?
>
> I guess struct ref_formatting_state and struct align could be moved to
> ref-filter.c. About struct atom_value its referenced by ref_array_item()
> so any reader reading about this, would find it easier if atom_value()
> is at the same place.

Do you expect callers ever to be manipulating or otherwise accessing
the atom_value of ref_array_item? If callers have no business mucking
with atom_value, then one option would be to simply forward declare
atom_value in the header:

    struct atom_value;

    struct ref_array_item {
        ...
        struct atom_value *value;
        ...
    };

which makes atom_value opaque to clients of ref-filter. The actual
declaration of atom_value would then be moved to ref-filter.c, thus
kept private.