https://github.com/hargettp/hh-redblack.git
git clone 'https://github.com/hargettp/hh-redblack.git'
(ql:quickload :hh-redblack)
hh-redblack
This package is a Common Lisp implemention of red-black trees (http://en.wikipedia.org/wiki/Red-black_tree) using the algorithms described in Introduction to Algorithms, by Thomas H. Cormen, Charles E. Leiserson, Ronald L. Rivest, and Clifford Stein.
In addition to a straight-forward in-memory implementation of red-black trees, an implementation of a persistent tree is also included. The persistent implementation uses a text file for storage (for human readability), and uses an append-only strategy for updating that text file. A footer always appears at the end of the file (actually, a footer and a backup copy of the footer), containing information about where the root of the tree is located and other relevant housekeeping details. A small header appears at the beginning of the file containing a version number for the tree's storage format. Under correct behavior, at no time is any byte of the file written more than once.
Contact phil@haphazardhouse.net for any questions, comments, feedback, or contributions, and keep an eye on http://haphazardhouse.net/projects/hh-redblack for info and news about hh-redblack.
Thanks!