例如,这是一个已定义的ruby文字列表.ruby是否为我们提供了一种定义新"定制"的方法?
[更新]目的是简化对象实例化的过程.例如,如果我想基于某种动态语言创建对象,我希望有这样的东西:
obj = @|
rule1 = "..."
rule2 = "..."
value1 = "..."
value2 = "..."
|
Run Code Online (Sandbox Code Playgroud)
代替
hash = {rule1: "...", rule2: "...", value1: "...", value2: "..."}
obj = MyObj.new(hash)
Run Code Online (Sandbox Code Playgroud)
不可以.在Ruby程序中无法改变Ruby的语法.
如果你想定义一个新的文字,你必须在Ruby bugtracker上提出它,说服matz这是一个好主意,然后说服开发者YARV,JRuby,Rubinius,IronRuby,MRuby,MagLev,Topaz,Cardinal,tinyrb ,MacRuby,RubyMotion,BlueRuby,Opal,XRuby,Ruby.NET,Alumina,SmallRuby,或者您关心实现它的任何实现,然后等待社区更新到更新版本的实现.
我想要这样的东西:
Run Code Online (Sandbox Code Playgroud)obj = @| rule1 = "..." rule2 = "..." value1 = "..." value2 = "..." |
这是不可能的,但您可以构建非常相似的东西:
obj = MyObj.build {
rule1 'foo'
rule2 'bar'
value1 'baz'
value2 'qux'
}
obj #=> #<MyObj:0x007fcd7d01ee90 @rule1="foo", @rule2="bar", @value1="baz", @value2="qux">
Run Code Online (Sandbox Code Playgroud)
执行:
class Builder
def initialize(obj)
@obj = obj
end
def method_missing(name, value)
@obj.public_send("#{name}=", value)
end
end
class MyObj
attr_accessor :rule1, :rule2, :value1, :value2
def self.build(&block)
new.tap { |obj| Builder.new(obj).instance_eval(&block) }
end
end
Run Code Online (Sandbox Code Playgroud)