[Rd] tree/graph data structure APIs?

[Andrew Piskorski]

What is the best code available for simple general purpose
manipulation of tree (and/or directed graph) data structures in R?

Looking through CRAN, I see a bunch of packages for stastical
regression trees, but nothing that seems to provide an API for
manipulating tree data structures.  What I'm looking for is something
along the lines of an R version of the Tcllib ::struct::tree API
available for Tcl:

  http://wiki.tcl.tk/210
  http://tcllib.sourceforge.net/doc/struct_tree.html
  http://tcllib.sourceforge.net/doc/graph.html

Thanks!

-- 
Andrew Piskorski <atp at piskorski.com>
http://www.piskorski.com/