On Tue, 27 Dec 2016, Sašo Živanović wrote:
I'm the author of a PGF/TikZ-based LaTeX package Forest for drawing (linguistic) trees. I have received several requests to support ConTexT and I'm trying to do that now.
Thank you for trying to port your code to ConTeXt. Although I don't foresee that I will use the forest package, I do use pgfplots quite a lot and appreciate the extra effort put in by the package authors to support two different macro packages.
Forest uses a lot of \boxes. Actually, the number of boxes used cannot be known in advance, as it depends on the document. Here's why: Forest's main job is to place the nodes of a tree so that they don't overlap and to do that, it needs to first typeset the individual nodes and measure them. The typeset nodes are kept around and later used when typesetting the entire tree.
I don't have an answer to your questions, but I am replying partly to bump this thread again.
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} % Do some measurement based on the size of the boxes \egroup The fact that a LaTeX package implements this behaviour by allocating local box numbers from the end seems to be an implementation detail. 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 :-) Aditya