2 Examples top

• link | changes

  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
• link | changes

  ;; Create a promise
  user> (def p (promise))
  #'user/p ; p is our promise
  
  ;; Check if was delivered/realized
  user> (realized? p)
  false ; No yet
  
  ;; Delivering the promise
  user> (deliver p 42)
  #<core$promise$reify__5727@47122d: 42>
  
  ;; Check again if it was delivered
  user> (realized? p)
  true ; Yes!
  
  ;; Deref to see what has been delivered
  user> @p
  42
  
  ;; Note that @ is shorthand for deref
  user> (deref p)
  42
  

  ;; Create a promise user> (def p (promise)) #'user/p ; p is our promise ;; Check if was delivered/realized user> (realized? p) false ; No yet ;; Delivering the promise user> (deliver p 42) #<core$promise$reify__5727@47122d: 42> ;; Check again if it was delivered user> (realized? p) true ; Yes! ;; Deref to see what has been delivered user> @p 42 ;; Note that @ is shorthand for deref user> (deref p) 42