[NTG-context] Math literal colon

[Hans Aberg]

> On 24 Jul 2015, at 15:48, Hans Hagen <pragma at wxs.nl> wrote:

>> In the examples I mentioned (below), running ‘context’ on the first produces large colons, whereas ‘luatex’ on the second does not. The latter looks right to me.
> 
> define 'luatex' ... it's all about choices that macro packages make (or made in the past)

I use Tex Live 2015 that came last month.

$ luatex --version
This is LuaTeX, Version beta-0.80.0 (TeX Live 2015) (rev 5238)

> 
>> There is a similar issue with integral symbols, where somehow ConTeXt add additional spacing after it.
>>   http://www.ntg.nl/pipermail/ntg-context/2015/082541.html
>> 
>> 
>> — context —
>> \setupbodyfont[xits,10pt]
>> 
>> \setupformulas[location=left]
>> 
>> \begingroup\lccode`\~=`\:\lowercase{\endgroup
>>      \let~}\colon
>>    \mathcode`\:="8000 %
>> 
>> \starttext
>> 
>> The function $f: A → B$, $g\colon A → B$.
> 
> we could add a mathsymbol entry but I leave that to Aditya to decide
> 
> {
>  adobename="colon",
>  category="po",
>  cjkwd="na",
>  description="COLON",
>  direction="cs",
>  linebreak="is",
>  mathclass="relation",
> --mathsymbol=0x2236,
>  unicodeslot=0x3A,
> },


Should it be 'mathclass=“relation”’? Mathematically, relations have extra space at both sides, whereas in the function $f: A → B$, there should not be much space before the “:”.