Groovy代表按预期工作？ [英] Groovy delegates working as intended?

问题描述

我有一个简短的代码片段，我尝试将可变分辨率委托给委托人。然而代理人的价值没有被使用，而是使用所有者的价值。这是故意的还是这个bug？

  class Person {
 int age 
} 
 
 def age = -5 
 def closure = { - >年龄} 
 closure.delegate = new Person（年龄：99）
 closure.resolveStrategy == Closure.DELEGATE_ONLY 
 
断言closure.call（）== 99 
  

以上代码失败，返回-5。

解决方案

你的代码返回 -5 ，因为变量 age 是用关闭的词汇范围，这意味着关闭可以使用变量 age 的值。

您必须明确地告诉闭包使用委托的age属性：

  def closure = { - > 
 $ / code> 

请尝试以下代码：

  class Person {
 int age 
} 
 def age = -5 
 def closure = { - > delegate.age * age} 
 closure.delegate = new Person（age：99）
 closure.resolveStrategy == Closure.DELEGATE_ONLY 
 assert closure.call（）== 99 * -5 
  




I have a short snippet where I try to delegate the variable resolution to the delegate. However the delegates value isnt used, instead the owners value is used. Is this intentional or is this a bug?

class Person {
    int age
}

def age = -5
def closure = { -> age }
closure.delegate = new Person(age: 99)
closure.resolveStrategy == Closure.DELEGATE_ONLY

assert closure.call() == 99

Above code fails, with the closure returning -5.

解决方案

Your code returns -5 because the variable age is defined withing the lexical scope of the closure, meaning that the closure can use the value of the variable age.

You have to explicitly tell the closure to use the age property of the delegate:

def closure = { -> delegate.age }

Try the following code:

class Person {
    int age
}  
def age = -5 
def closure = { -> delegate.age * age } 
closure.delegate = new Person(age: 99)
closure.resolveStrategy == Closure.DELEGATE_ONLY 
assert closure.call() == 99*-5

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