Ruby:定义实例变量的简短方法

Question

我正在寻找在方法中定义实例变量的更短initialize方法:

class MyClass
  attr_accessor :foo, :bar, :baz, :qux
  # Typing same stuff all the time is boring
  def initialize(foo, bar, baz, qux)
    @foo, @bar, @baz, @qux = foo, bar, baz, qux
  end
end

Ruby有没有任何内置功能可以避免这种猴子的工作？

# e. g.
class MyClass
  attr_accessor :foo, :bar, :baz, :qux
  # Typing same stuff all the time is boring
  def initialize(foo, bar, baz, qux)
    # Leveraging built-in language feature
    # instance variables are defined automatically
  end
end

Answer 1

Meet Struct,专为此而设计的工具!

MyClass = Struct.new(:foo, :bar, :baz, :qux) do
  # Define your other methods here. 
  # Initializer/accessors will be generated for you.
end

mc = MyClass.new(1)
mc.foo # => 1
mc.bar # => nil

我经常看到人们像这样使用Struct:

class MyStruct < Struct.new(:foo, :bar, :baz, :qux)
end

但是这导致一个额外的未使用的类对象.为什么在不需要时创建垃圾？