On 23. 01. 2017 09:26, Aditya Mahajan wrote:
I don't have an answer to your questions, but I am replying partly to bump this thread again. Thanks!
The typeset nodes are kept in "local" boxes. They are created using \locbox, which is defined either by plain eTeX format or package elocalloc.sty for LaTeX >2015. (Prior to LaTeX 2015, \locbox was defined in etex.sty.) elocalloc.sty's \locbox is somewhat broken, but still works, mainly because it seems no other package is using local allocation. ;-)
Let me see if I understand this correctly.
You are asking how to define a macro, \locbox, such that the following code should not change the value of \c_syst_last_allocated_box.
\bgroup \locbox\BoxOne \locbox\BoxTwo
\BoxOne\hbox{Box One} \BoxTow\hbox{Box Two} You probably meant \setbox\BoxOne\hbox{Box One} % Do some measurement based on the size of the boxes \egroup Essentially, yes.
The intro section to package localloc (afaik, historically the first package to implement local register allocation) might shed some light on the issue as well. http://ctan.org/pkg/localloc
The fact that a LaTeX package implements this behaviour by allocating local box numbers from the end seems to be an implementation detail. True, although I'm not aware of any other possibility to implement this.
I don't know the best way to implement such a macro in ConTeXt, but I want to make sure that the user-level behavior that you want is properly understood. Given the details in your question, one can easily lose the forest for the trees (pun intended :-) Damn. Precisely what the users say about my documentation! ;-)
Best, Sašo
Aditya