The document discusses the self keyword in Ruby. It provides examples of how self refers to the enclosing class or module from within a class or module definition. It also shows how self refers to the instance of a class from within an instance method.

1. self
@ 80 ruby

2. • :
• SNS: @yalab
• :
• : ( )
• ruby : since 1.6
• : ruby trunk mjit merge

5. 1 name = "Yoshida" #
2 name.size #

6. 1 name = "Yoshida" #
2 name.size #

7. 1 name = "Yoshida" #
2 name.size #

9. 1 public_methods

10. • )
• )

12. 1 self.public_methods

13. "self"
Y^Y^Y^Y^Y^Y

14. self

15. 1 p self #=> main
2
3 class A
4 p self #=> A
5 def method
6 p self #=> #<A:0x007fdf1002cf28>
7 end
8
9 def self.classmethod
10 p self #=> A
11 end
12 end
13
14 A.module_eval do
15 p self #=> A
16 end

19. 1 class Animal
2 def type
3 :animal
4 end
5 end
6
7 class Human < Animal
8 def initialize(name)
9 @name = name
10 end
11
12 def name
13 "#{@name}(#{type})" #<- type
14 end
15 end

20. 1 class User < ApplicationRecord
2 validates :name, presence: true
3 end

21. 1 class User < ApplicationRecord
2 self.validates(:name, {presence: true})
3 end

22. 1 class User < ApplicationRecord
2 validates :name, presence: true
3 end

23. )private
self

24. self

25. 1 p self.class #=>
2 p self.class.ancestors #=>
3 p self.instance_variables #=>
4 p self.methods #=>
5 p self.methods.grep /write/ #=>
6 p self.method(:tap).source_location #=>

26. Object,Class,Module
https://docs.ruby-lang.org/ja/2.5.0/class/Object.html
https://docs.ruby-lang.org/ja/2.5.0/class/Class.html
https://docs.ruby-lang.org/ja/2.5.0/class/Module.html

27. self ruby

28. self
self