elixir - 使用 i 来查看某个变量的具体情况（类似与 ruby 的 .inspect)

参考：https://stackoverflow.com/questions/28377135/how-do-you-check-for-the-type-of-variable-in-elixir

iex(10)> i %{ 1 => 10, 2 => 20}
Term
%{1 => 10, 2 => 20}
Data type
Map
Reference modules
Map
Implemented protocols
Collectable, Enumerable, IEx.Info, Inspect

不过还有更好的办法 

IO.puts "===== hi ,now print inspect"

IO.inspect some_var

遇到下面的问题怎么办？

** (Mix) Could not start application explorer: Explorer.Application.start(:normal, []) returned an error: shutdown: failed to start child: Explorer.Chain.Events.Listener
    ** (EXIT) an exception was raised:
        ** (ArgumentError) cannot convert the given list to a string.

To be converted to a string, a list must either be empty or only
contain the following elements:

  * strings
  * integers representing Unicode code points
  * a list containing one of these three elements

你一定是在代码里面这样写了：  IO.puts "==== hi #{some_var}"  如果some_var是个数组，这里就会报错。

写成这样： 

IO.puts "=== hi #{inspect some_var}"