There is a common pattern in OOP land that you use ooo.setXXX(yyy) to dupe states across objects/fields. Instead of using some kind of getters to map them. (pro

There is a common pattern in OOP land that you use ooo.setXXX(yyy) to dupe states across objects/fields. Instead of using some kind of getters to map them. (probably due to difficulty in languages to link between objects?) You end up get some states that should just the same but in multi places. And this is almost one of a biggest source of bugs. Because you WILL do it wrong. As the code grows, the place you need to manual synchronize data grows. You end up miss it, create a lot of bugs. On the other end, in most FP languages. It is pointless to dupe state most of the time, so this kind of problems did not happen so much in the first place. BTW: Personally I like the idea of the [computed](https://v3.cn.vuejs.org/api/computed-watch-api.html#computed https://v3.cn.vuejs.org/api/computed-watch-api.html#computed) primitive of vue, because it make the getter/setters first party encouraged. And getter/setters never add states. If you use it properly, states can be reduced by a lot and with much shorter code. While it looks the same as manually dupe them on surface, so you don't need refactor everything just to use it.