Question

我想知道如何在3_000毫秒之后跳到此功能的结尾，但屏幕上没有任何其他打印消息或调用其他功能或发送更多消息。

defmodule ExampleModule do

    def main do
        Process.send_after(self(), :hello, 2_000)
        send self(), :hello_again
        next()
    end

    def next do
        receive do
            :hello -> IO.puts("Received hello") 
            :hello_again -> IO.puts("Received hello_again")
            after 3_000 -> <SKIP to the very end without recursion>
       end 
        next()
    end
end

Answer 1

Elixir中没有goto或return等构造。您可以通过以下两种方式解决此问题：

在要继续递归的分支中明确调用next()：

def next do
  receive do
    :hello ->
      IO.puts("Received hello") 
      next()
    :hello_again ->
      IO.puts("Received hello_again")
      next()
    after 3_000 ->
      :ok
  end 
end

存储接收表达式的值并根据以下内容调用next()：

def next do
  continue = receive do
    :hello ->
      IO.puts("Received hello") 
      true
    :hello_again ->
      IO.puts("Received hello_again")
      true
    after 3_000 ->
      false
  end 
  if continue, do: next()
end

Elixir跳过运算符而不是另一条消息？

1 个答案: