Where to find a list of all system-defined counters in ConTeXt?

Question

I learned from How to obtain the current page number in ConTeXt? that I can obtain the page number counter value using tex.count.pageno, but I have not found this mentioned in any available documentation. I wonder, what other counters are available? Is there some place which has a complete list?

Answer 1

The snippet tex.count.pageno is just luatex's representation of \pageno, which is more obvious when you realize that it is shorthand for tex.count["pageno"]. All of the \newcount-defined counters are accessible from lua that way, as well as anonymous counters by using tex.count[0], and that is in no way ConTeXt-specific.

There is no published list of \newcount defined counters in ConTeXt. You can grep the ConTeXt source for \newcount, but most of the counters are for internal use only and of no interest to normal users. \pageno is a bit of an exception because it is in use in plain TeX and inherited from there.

The more interesting counters in ConTeXt are defined using \definecounter, and these can be listed using code like this:

\startlua
table.print(structures.counters.data)
\stoplua

The counters associated with sectioning levels do not live there ,and I do not know where those are. Hopefully someone else will know.