Elixirの対話モードでaliasとrequireおよびimportの動作を確認してみた

# 概要
Elixirの対話モードでaliasとrequireおよびimportの動作を確認してみました。以下のページを参考にしました。

https://dev.to/gumi/elixir-13-aliasrequireimport-55c1

# 対話モードで実行
以下のコマンドを実行しました。
```
$ iex
Erlang/OTP 24 [erts-12.2.1] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:1] [jit]

Interactive Elixir (1.12.2) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> defmodule Sayings.Greetings do
...(1)> def basic(name), do: "hello, #{name}"
...(1)> end
{:module, Sayings.Greetings,
 <<70, 79, 82, 49, 0, 0, 5, 184, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 193,
   0, 0, 0, 18, 24, 69, 108, 105, 120, 105, 114, 46, 83, 97, 121, 105, 110, 103,
   115, 46, 71, 114, 101, 101, 116, 105, 110, ...>>, {:basic, 1}}
iex(2)> defmodule Example do
...(2)> def greeting(name), do: Sayings.Greetings.basic(name)
...(2)> end
{:module, Example,
 <<70, 79, 82, 49, 0, 0, 5, 28, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 173,
   0, 0, 0, 16, 14, 69, 108, 105, 120, 105, 114, 46, 69, 120, 97, 109, 112, 108,
   101, 8, 95, 95, 105, 110, 102, 111, 95, ...>>, {:greeting, 1}}
iex(3)> Example.greeting("world")
"hello, world"
iex(4)> defmodule Example do
...(4)> alias Sayings.Greetings
...(4)> def greeting(name), do: Greetings.basic(name)
...(4)> end
warning: redefining module Example (current version defined in memory)
  iex:4

{:module, Example,
 <<70, 79, 82, 49, 0, 0, 5, 28, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 173,
   0, 0, 0, 16, 14, 69, 108, 105, 120, 105, 114, 46, 69, 120, 97, 109, 112, 108,
   101, 8, 95, 95, 105, 110, 102, 111, 95, ...>>, {:greeting, 1}}
iex(5)> alias Example, as: String
Example
iex(6)> String.greeting("tokyo")
"hello, tokyo"
iex(7)> Elixir.String.length("hello")
5
iex(8)> defmodule Example do
...(8)> alias Sayings.Greetings, as: Hi
...(8)> def greeting(name), do: Hi.basic(name)
...(8)> def greeting_ex(name), do: Hi.basic(name) <> "!!"
...(8)> end
warning: redefining module Example (current version defined in memory)
  iex:8

{:module, Example,
 <<70, 79, 82, 49, 0, 0, 6, 32, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 185,
   0, 0, 0, 17, 14, 69, 108, 105, 120, 105, 114, 46, 69, 120, 97, 109, 112, 108,
   101, 8, 95, 95, 105, 110, 102, 111, 95, ...>>, {:greeting_ex, 1}}
iex(9)> Example.greeting_ex("world")     
"hello, world!!"
iex(10)> defmodule Example do
...(10)> def greeting(name) do
...(10)> alias Sayings.Greetings, as: Hi
...(10)> Hi.basic(name)
...(10)> end
...(10)> def greeting_ex(name), do: Hi.basic(name) <> "!!"
...(10)> end
warning: redefining module Example (current version defined in memory)
  iex:10

{:module, Example,
 <<70, 79, 82, 49, 0, 0, 6, 80, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 195,
   0, 0, 0, 18, 14, 69, 108, 105, 120, 105, 114, 46, 69, 120, 97, 109, 112, 108,
   101, 8, 95, 95, 105, 110, 102, 111, 95, ...>>, {:greeting_ex, 1}}
iex(11)> Example.greeting("world")
"hello, world"
iex(12)> Example.greeting_ex("world")
** (UndefinedFunctionError) function Hi.basic/1 is undefined (module Hi is not available)
    Hi.basic("world")
    iex:15: Example.greeting_ex/1
iex(12)> Integer.is_odd(5)
** (UndefinedFunctionError) function Integer.is_odd/1 is undefined or private. However there is a macro with the same name and arity. Be sure to require Integer if you intend to invoke this macro
    (elixir 1.12.2) Integer.is_odd(5)
iex(12)> require Integer
Integer
iex(13)> Integer.is_odd(5)
true
iex(14)> import List
List
iex(15)> first([1, 2, 3])
1
iex(16)> last([1, 2, 3])
3
iex(17)> flatten([1, [[2], 3]])
[1, 2, 3]
iex(18)> import List, only: [first: 1, last: 1]
List
iex(19)> first([1, 2, 3])
1
iex(20)> flatten([1, [[2], 3]])
** (CompileError) iex:20: undefined function flatten/1

iex(20)> import Integer, only: :macros
Integer
iex(21)> is_even(4)
true
iex(22)> digits(123)
** (CompileError) iex:22: undefined function digits/1

iex(22)> Integer.digits(123)
[1, 2, 3]
iex(23)> import Integer, only: :functions
Integer
iex(24)> digits(123)
[1, 2, 3]
iex(25)> is_odd(3)
** (CompileError) iex:25: undefined function is_odd/1

iex(25)> import List, except: [first: 1, last: 1]
List
iex(26)> flatten([1, [[2], 3]])
** (CompileError) iex:26: undefined function flatten/1

iex(26)> last([1, 2, 3])
** (CompileError) iex:26: undefined function last/1

iex(26)> defmodule Example do
...(26)> def split(number) do
...(26)> import Integer, only: [digits: 1]
...(26)> digits(number)
...(26)> end
...(26)> def test(name), do: digits(name)
...(26)> end
warning: redefining module Example (current version defined in memory)
  iex:26

{:module, Example,
 <<70, 79, 82, 49, 0, 0, 5, 156, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 166,
   0, 0, 0, 17, 14, 69, 108, 105, 120, 105, 114, 46, 69, 120, 97, 109, 112, 108,
   101, 8, 95, 95, 105, 110, 102, 111, 95, ...>>, {:test, 1}}
iex(27)> defmodule Hello do
...(27)> defmacro __using__(_opts) do
...(27)> quote do
...(27)> def greeting(name), do: "hello, #{name}"
...(27)> end
...(27)> end
...(27)> end
{:module, Hello,
 <<70, 79, 82, 49, 0, 0, 5, 224, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 147,
   0, 0, 0, 14, 12, 69, 108, 105, 120, 105, 114, 46, 72, 101, 108, 108, 111, 8,
   95, 95, 105, 110, 102, 111, 95, 95, 10, ...>>, {:__using__, 1}}
iex(28)> defmodule Example do
...(28)> use Hello
...(28)> end
warning: redefining module Example (current version defined in memory)
  iex:28

{:module, Example,
 <<70, 79, 82, 49, 0, 0, 5, 216, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 186,
   0, 0, 0, 18, 14, 69, 108, 105, 120, 105, 114, 46, 69, 120, 97, 109, 112, 108,
   101, 8, 95, 95, 105, 110, 102, 111, 95, ...>>, {:greeting, 1}}
iex(29)> Example.greeting("world")
"hello, world"
iex(30)> defmodule Example do
...(30)> require Hello
...(30)> Hello.__using__(greeting: :value)
...(30)> end
warning: redefining module Example (current version defined in memory)
  iex:30

{:module, Example,
 <<70, 79, 82, 49, 0, 0, 5, 216, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 186,
   0, 0, 0, 18, 14, 69, 108, 105, 120, 105, 114, 46, 69, 120, 97, 109, 112, 108,
   101, 8, 95, 95, 105, 110, 102, 111, 95, ...>>, {:greeting, 1}}
iex(31)> defmodule Hello do
...(31)> defmacro __using__(opts) do
...(31)> hello = Keyword.get(opts, :hello, "hello")
...(31)> quote do
...(31)> def greeting(name), do: unquote(hello) <> "," <> name
...(31)> end
...(31)> end
...(31)> end
warning: redefining module Hello (current version defined in memory)
  iex:31

{:module, Hello,
 <<70, 79, 82, 49, 0, 0, 6, 92, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 182,
   0, 0, 0, 20, 12, 69, 108, 105, 120, 105, 114, 46, 72, 101, 108, 108, 111, 8,
   95, 95, 105, 110, 102, 111, 95, 95, 10, ...>>, {:__using__, 1}}
iex(32)> defmodule Example do
...(32)> use Hello, hello: "こんにちは"
...(32)> end
warning: redefining module Example (current version defined in memory)
  iex:32

{:module, Example,
 <<70, 79, 82, 49, 0, 0, 5, 148, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 156,
   0, 0, 0, 16, 14, 69, 108, 105, 120, 105, 114, 46, 69, 120, 97, 109, 112, 108,
   101, 8, 95, 95, 105, 110, 102, 111, 95, ...>>, {:greeting, 1}}
iex(33)> Example.greeting("日本")
"こんにちは,日本"
iex(34)> is_atom(String)
true
iex(35)> to_string(String)
** (CompileError) iex:35: function to_string/1 imported from both Integer and Kernel, call is ambiguous
    (elixir 1.12.2) src/elixir_dispatch.erl:128: :elixir_dispatch.expand_import/6
    (elixir 1.12.2) src/elixir_dispatch.erl:91: :elixir_dispatch.dispatch_import/5
iex(35)> String == :"Elixir.String"
false
iex(36)> :lists.flatten([1, [[2], 3]])
[1, 2, 3]
iex(37)> defmodule Example do
...(37)> def greeting(name), do: "hello, #{name}"
...(37)> defmodule Greetings do
...(37)> def morning(name), do: "good morning, #{name}"
...(37)> end
...(37)> end
warning: redefining module Example (current version defined in memory)
  iex:37

{:module, Example,
 <<70, 79, 82, 49, 0, 0, 5, 188, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 186,
   0, 0, 0, 18, 14, 69, 108, 105, 120, 105, 114, 46, 69, 120, 97, 109, 112, 108,
   101, 8, 95, 95, 105, 110, 102, 111, 95, ...>>,
 {:module, Example.Greetings,
  <<70, 79, 82, 49, 0, 0, 5, 204, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 195,
    0, 0, 0, 18, 24, 69, 108, 105, 120, 105, 114, 46, 69, 120, 97, 109, 112,
    108, 101, 46, 71, 114, 101, ...>>, {:morning, 1}}}
iex(38)> Example.greeting("world")
"hello, world"
iex(39)> Example.Greetings.morning("tokyo")
"good morning, tokyo"
iex(40)> defmodule Example do
...(40)> def greeting(name), do: "hello, #{name}"
...(40)> defmodule Greetings do
...(40)> def morning(name), do: "good morning, #{name}"
...(40)> end
...(40)> def call_child(name), do: Greetings.morning(name)
...(40)> end
warning: redefining module Example (current version defined in memory)
  iex:40

warning: redefining module Example.Greetings (current version defined in memory)
  iex:42

{:module, Example,
 <<70, 79, 82, 49, 0, 0, 6, 184, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 230,
   0, 0, 0, 21, 14, 69, 108, 105, 120, 105, 114, 46, 69, 120, 97, 109, 112, 108,
   101, 8, 95, 95, 105, 110, 102, 111, 95, ...>>, {:call_child, 1}}
iex(41)> Example.call_child("japan")
"good morning, japan"
iex(42)> defmodule Example do
...(42)> def greeting(name), do: "hello, #{name}"
...(42)> end
warning: redefining module Example (current version defined in memory)
  iex:42

{:module, Example,
 <<70, 79, 82, 49, 0, 0, 5, 184, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 186,
   0, 0, 0, 18, 14, 69, 108, 105, 120, 105, 114, 46, 69, 120, 97, 109, 112, 108,
   101, 8, 95, 95, 105, 110, 102, 111, 95, ...>>, {:greeting, 1}}
iex(43)> defmodule Example.Greetings do
...(43)> def morning(name), do: "good morning, #{name}"
...(43)> end
warning: redefining module Example.Greetings (current version defined in memory)
  iex:43

{:module, Example.Greetings,
 <<70, 79, 82, 49, 0, 0, 5, 204, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 195,
   0, 0, 0, 18, 24, 69, 108, 105, 120, 105, 114, 46, 69, 120, 97, 109, 112, 108,
   101, 46, 71, 114, 101, 101, 116, 105, 110, ...>>, {:morning, 1}}
iex(44)> defmodule Example.Greetings.Japan do
...(44)> def greeting(name), do: "こんにちは, #{name}"
...(44)> end
{:module, Example.Greetings.Japan,
 <<70, 79, 82, 49, 0, 0, 5, 248, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 202,
   0, 0, 0, 18, 30, 69, 108, 105, 120, 105, 114, 46, 69, 120, 97, 109, 112, 108,
   101, 46, 71, 114, 101, 101, 116, 105, 110, ...>>, {:greeting, 1}}
iex(45)> Example.Greetings.Japan.greeting("日本")
"こんにちは, 日本"
iex(46)> alias Example.Greetings.{US, Japan}
[Example.Greetings.US, Example.Greetings.Japan]
iex(47)> 
```

# まとめ
何かの役に立てばと。