Purely Functional Data Structures
pfds is a set of purely functional data structures written in R6RS Scheme. It has been tested with Racket, Guile 2, Vicare Scheme and IronScheme. Right now it contains: queues, deques, bbtrees, sets, dlists, priority search queues (psqs), finger trees, sequences, heaps, hamts; with more to come, time permitting.
$ akku install pfds $ .akku/env