[NTG-context] xml expression error

Meer, Hans van der H.vanderMeer at uva.nl
Thu Apr 28 23:12:22 CEST 2016


> On 28 Apr 2016, at 22:13, Pablo Rodriguez <oinos at gmx.es> wrote:
> 
> On 04/28/2016 05:06 PM, dr. Hans van der Meer wrote:
>> Why is there anexpression error here? I would expect that the expression
>> number(-10000101) evaluates to a negative number taking part in the
>> comparsion. It looks as if the minus sign is not seen as an unary minus,
>> while -10000101 should have be evaluated by Lua's tonumber(-10000101).
>> 
>> relevant code snippet is:
>> \xmlfilter{#1}{lpath[number(@date) <= number(-10000101)]/command(...)
> 
> Sorry, Hans, I guess my question will be stupid, but why don’t use
> "tonumber(-10000101)"?

It is convenient to use positive numbers for dates after the year 0: AD = Anno Domine,
and negative numbers for years before: BC = Before Christ.
Comparing dates is easy in both eras.

> 
> I wouldn’t get it, even with a minimal sample, but xml-mkiv.pdf includes
> the shortcut for this function.
> 
> Just in case it might even help ;-),

Has to wait until tomorrow, because it is already late in the evening.

Hans van der Meer






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