什么是AngularJS中的状态过滤？(What is stateful filtering in AngularJS?)

 我正在阅读AngularJS开发者指南，并在“过滤器”部分（ https://docs.angularjs.org/guide/filter#stateful-filters ）中查看“状态过滤器”。 
 
 给出了以下描述： 
 
 
 
 非常不鼓励编写有状态的过滤器，因为它们的执行不能被Angular进行优化，这往往会导致性能问题。 只有将隐藏状态作为模型并将其转换为过滤器的参数，才能将许多状态过滤器转换为无状态过滤器。 
 
 
 我是Web开发的新手，所以不知道什么是状态过滤，Angular文档没有解释它:(有人可以解释一个正常的过滤器和状态过滤器之间的区别是什么？ 

I was reading the AngularJS developer guide on the Filter section (https://docs.angularjs.org/guide/filter#stateful-filters) and came across "Stateful Filters". 
 
This description is given as follows:
 
 
 
It is strongly discouraged to write filters that are stateful, because the execution of those can't be optimized by Angular, which often leads to performance issues. Many stateful filters can be converted into stateless filters just by exposing the hidden state as a model and turning it into an argument for the filter.
 
 
I'm new to web development, so have no idea what Stateful filtering is, and Angular Documentation didn't explain it either :( Can someone please explain what is the difference between a normal filter and a stateful filter is?

原文：https://stackoverflow.com/questions/25877704