Re: [PATCH v10 05/13] ref-filter: implement an `align` atom

[Junio C Hamano <gitster@pobox.com>]

Karthik Nayak <karthik.188@gmail.com> writes:

> On Wed, Aug 12, 2015 at 12:22 AM, Junio C Hamano <gitster@pobox.com> wrote:
>
>> Minor nits on the design.  %(align:<width>[,<position>]) would let
>> us write %(align:16)...%(end) and use the "default position", which
>> may be beneficial if one kind of alignment is prevalent (I guess all
>> the internal users left-align?)  %(align:<position>,<width>) forces
>> users to spell both out all the time.
>>
>
> Isn't that better? I mean It sets a format which the others eventually
> can follow
> %(atom:suboption,value).
> For example: %(objectname:abbrev,size)

No, I do not think it is better.  First of all, the similarity you
are perceiving does not exist.  For 'objectname:abbrev', the 'size'
is a property of the 'abbrev'.  For 'align:left', the 'width' is not
a property of the position.  It is a property given to 'align'
(i.e. you have this many display columns to work with).

Also, if there are ways other than 'abbrev' that '8' could affect
the way how %(objectname) is modified, then it should be spelled as
%(objectname:abbrev=8).  To specify two modification magics, each of
which takes a number, the user would say e.g.

    %(objectname:abbrev=8,magic=4)

The syntax %(objectname:abbrev,size) would not allow you to extend
it nicely---you would end up with %(objectname:abbrev,8,magic,4) or
something silly like that.

Seeing your %(objectname:abbrev,size), I'd imagine that you are
assuming that you will never allow any magic other than 'abbrev'
that takes a number to %(objectname).  And under that assumption
%(objectname:8) would be a short-hand for %(objectname:8,abbrev).

And that would be following %(align:8).  Both 'left' (implied
default) and '8' are instructing 'align' what to do.