Package rbtree provides an iterative (not recursive) red-black tree with
obvious semantics and powerful, resettable iteration.
This package was born out of a need to modify elements during tree iteration. Most packages do not provide an obvious way to efficiently "reset" a node or an iterator. To aid in this need, this package primarily operates on the basis of nodes rather than node items.
For more information about a red-black tree, and to understand the implementation, see Wikipedia.
