#!r6rs
(library (rsc3 graphdef id)
(export make-uid uid? unique-uid)
(import (rnrs))

(define-record-type uid (fields value))

;; Counting from 1...

(define unique-uid
  (let ((id 0))
    (lambda ()
      (set! id (+ id 1))
      (make-uid id))))

)