For example, the following conditional expression: if m>future factorial(n) then print("bigger") else print("smaller") suspends until the future for factorial(n) has responded to the request asking if m is greater than itself.
例如，以下条件表达式： if m>future factorial(n) then print("bigger") else print("smaller") 会挂起，直到factorial(n)这个future已回应询问m是否大于其自身的请求。