[NTG-context] mkiv digits/units zero padding not working

[Benjamin Buchmuller]

Following up on the work-around, here is my improved code for xtable.

What doesn’t work is:

* alignment on the decimal separator takes place only in the first column with decimals (i.e. B), not on the  following one; this is independent of R1 having a decimal value in this column or not

* row spanning is now tricky since the width of the header column is taken for the first of the three rows spanned, which becomes even more complicated with option=stretch, I guess if I right align the second column and would phantomize the hsize of the header, this could work with a bit of optimization.

What I like about this approach however is that one could read the two arguments from a CSV file, which would save a lot of typing (and to manually specify the padding).

\def\mpm#1#2{
	\doifsomethingelse{#2}{
	\startxcell[align=left] \digits{#1} \stopxcell
	\startxcell ± \stopxcell
	\startxcell \digits{#2} \stopxcell
	}{
	\startxcell[align=left] \digits{#1} \stopxcell
	\startxcell \stopxcell
	\startxcell \digits{#2} \stopxcell
	}
}

\startxtable[split=repeat, aligncharacter=yes, alignmentcharacter={.}]

	\startxtablehead
		\startxrow[topframe=on, foregroundstyle=bold]
		\startxcell A \stopxcell
		\startxcell[align=left, nx=3] Bla bla bla bla bla bla bla bla \stopxcell
		\startxcell C \stopxcell
		\stopxrow
	\stopxtablehead
	
	\startxtablebody
		\startxrow[topframe=on]
		\startxcell R1 \stopxcell
		\mpm{12.3}{}%{1.5}
		\startxcell one \stopxcell
		\stopxrow
		
		\startxrow
		\startxcell R2 \stopxcell
		\mpm{0.01}{0.023}
		\startxcell two \stopxcell
		\stopxrow
		
		\startxrow
		\startxcell R3 \stopxcell
		\mpm{2.3}{0.1}
		\startxcell three\stopxcell
		\stopxrow
		
	\stopxtablebody

\stopxtable	

> On 7 May 2020, at 21:22, Benjamin Buchmuller <benjamin.buchmuller at gmail.com> wrote:
> 
> Hi Wolfgang,
> 
> you are (of course) right again. I realised that I wouldn’t get the expected behaviour after checking the snippet isolated from my document’s context, where it is embedded in a \startplacetable[…]{}{}. I’m still learning to get the gist of the \doifs, the curly and square bracketed arguments and so on. Thanks for the hint! 
> 
> Seems like I’m going to make three cells and span the header column for now, though I guess it would be a nice feature to have the padding working in the other cases.
> 
> I’ll write a feature request for no 4.
> 
> Thanks!
> 
> 
>> On 7 May 2020, at 20:00, Wolfgang Schuster <wolfgang.schuster.lists at gmail.com> wrote:
>> 
>> Benjamin Buchmuller schrieb am 07.05.2020 um 19:41:
>>> Hi Wolfang,
>>> Thank you for your reply. I have indeed not explained my intended result very clearly.
>>> 1.
>>> Primarily, I need to get the two values aligned at the digit separator of the first and second number respectively and overall at the ± sign. I’m working in an xtable, where I have entries such as
>>> \startxcell \mpm{14.0==}{_1.5==} \stopxcell
>>> \startxcell \mpm{_0.034}{_0.013} \stopxcell
>>> and defined
>>> \def\mpm#1#2{
>>> 	\ifsecondargument
>>> 	\digits{#1}\,±\,\digits{#2}%
>>> 	\else
>>> 	\digits{#1}%
>>> 	\fi
>>> }
>> 
>> Is there something missing in here because the \ifsecondargument check here makes non sense because the second argument is mandatory and not optional.
>> 
>> Is this what you want?
>> 
>> \define[2]\mpm
>> {\digits{#1}%
>>  \doifsomething{#2}{\,±\,\digits{#2}}}
>> 
>>> Since I was hoping that I could exploit the zeropadding of \digits to get the format right. Indeed, it would save a lot of typing, if I wouldn’t have to specify the padding manually and I vaguely recall that there is somewhere a ConTeXt solution that can make such alignments, but I simply can’t find it any more …
>> 
>> You can align number on the decimal point (comma) but this works only when you have only one number in a cell.
>> 
>> \starttext
>> 
>> \startxtable[aligncharacter=yes,alignmentcharacter=±]
>>   \startxrow
>>       \startxcell
>>           \digits {14.0} ± \digits {1.5}
>>       \stopxcell
>>   \stopxrow
>>   \startxrow
>>       \startxcell
>>           \digits {0.034} ± \digits {0.013}
>>       \stopxcell
>>   \stopxrow
>> \stopxtable
>> 
>> \stoptext
>> 
>>> 2. + 3.
>>> Absolutely right, this is my bad. I have badly mixed from Hans’ solution to a similar problem,
>>> https://www.mail-archive.com/ntg-context@ntg.nl/msg00724.html
>>> which was actually \def\zeroamount{-} and the example in the source, I didn’t read properly. Just skip that part. :)
>> 
>> The message is from 2003!
>> 
>>> 4.
>>> Indeed,
>>> \startxcell \mpm{14.==}{_1.5=} \stopxcell
>>> \startxcell \mpm{_0.03}{_0.01} \stopxcell
>>> aligns properly. But sometimes, I have the first digit specified, but not the second and unfortunately this doesn’t work
>>> \startxcell \mpm{14.5=}{_1.5=} \stopxcell
>>> \startxcell \mpm{_0.03}{_0.01} \stopxcell
>>> because = is not immediately preceded by .
>> 
>> Can you write another mail with a request for this.
>> 
>> Wolfgang
>