persistent set data structure built on top of persistent hamt

gistfile1.lisp

(in-package :cl-user)

(defpackage pset
  (:use :cl :hamt)
  (:export put get make-pset)
  (:shadow put get))

(in-package pset)

(defstruct (pset
            (:print-function
             (lambda (struct stream depth)
               (declare (ignore struct depth))
               ;; TODO:
               (format stream ""))))
  (data (hamt:make-hamt)))

(defun put (pset item)
  (make-pset :data (hamt:put (pset-data pset) (hamt::make-keyval-pair item item))))

(defun get (pset item)
  (hamt:get (pset-data pset) item))