box-get-maybe

Type

meta-lisp

(all (E) (-> (box-t E) (maybe-t E)))

Description

Get the value from a box. Returns (nothing) if empty, (just value) otherwise.

Examples

meta-lisp

(define box (make-box))
(box-get-maybe box) ;; => (nothing)
(box-put box 42)
(box-get-maybe box) ;; => (just 42)