user=> (def x (promise)) #'user/x ;; Trying to deref at this point will make your repl wait forever user=> (deliver x 100) #<core$promise$reify__5534@4369a50b: 100> ;; the promise has been delivered, deref x will return immediately user=> @x 100
user=> (def x (promise)) #'user/x ;; Trying to deref at this point will make your repl wait forever user=> (deliver x 100) #<core$promise$reify__5534@4369a50b: 100> ;; the promise has been delivered, deref x will return immediately user=> @x 100
user=> (def x (promise)) ; Trying to deref at this point will make you're repl wait forever user=> (deliver x 100) ; the promise has been delivered, deref x will return immediately user=> @x 100