#lang scheme/base

;; scheme/promise has srfi-45-style primitives
(require scheme/promise)
(provide delay lazy force
         ;; Strictly speaking, this should be a procedure according to srfi-45.
         ;; It's easy to make it one, but then it loses its ability to deal
         ;; with multiple values (which the srfi completely ignores).
         (rename-out [delay/strict eager]))

;; TODO: there is a small difference between the primitives in srfi-45 and the
;; ones provided by scheme/promise (the latter is a bit more permissive).  See
;; "library approach" in scheme/promise and see the post-finalization
;; discussion on the srfi-45 list.  I (Eli) showed at some point how the
;; "language approach" primitives can be used to implement the other, and this
;; needs to be done here too.