elixir - 当计算机别名具有连字符时尝试连接节点时出现 "(ArithmeticError) bad argument in arithmetic expression"

Question

我正在学习一个教程，并且应该将节点连接在一起。我使用以下命令启动了总共四个终端窗口:

iex --sname one (two, three etc)

然后我运行

 Node.connect(:two@DAL-SW-JH-LT)
** (ArithmeticError) bad argument in arithmetic expression: :two@DAL - SW
    :erlang.-(:two@DAL, SW)

Answer 1

错误提示:

** (ArithmeticError) bad argument in arithmetic expression: :two@DAL - SW
:erlang.-(:two@DAL, SW)

也就是说，elixir尝试在那里调用减法运算符。我们唯一可疑的减法运算符是 -，它粘合节点名称的部分内容。

节点名称用原子表示。根据文档，Atom ...

...starts with a colon (:) which must be immediately followed by an underscore or a Unicode letter. The atom may continue using a sequence of Unicode letters, numbers, underscores, and @. Atoms may end in ! or ?. [...]

If the colon is immediately followed by a pair of double- or single-quotes surrounding the atom name, the atom is considered quoted. In contrast with an unquoted atom, this one can be made of any Unicode character (not only letters), such as :'🌢 Elixir', :"++olá++", and :"123".

也就是说，解决方案是引用原子，有效地用引号包围它

Node.connect(:"two@DAL-SW-JH-LT")

无论节点名称是否不包含破折号，都不需要引号。