perf: more light-weight computed

[shaonialife]

No description provided.

[antfu]

Interesting, can you have a simple pref comparison on this? Thanks

[shaonialife]

相对于原来的实现, 现在的 computed 只用到一个 Watcher 对象, 而原来的用到了 Vue对象, 在初始化 Vue 实例时, 需要做很多额外的工作, 比如调用生命周期方法等, 而且内存占用相对更多. 相比较而言, 只用 Watcher 对象要轻量得多, 我在项目中已经这样用了一个月多了, 没有发现什么奇怪的问题

[antfu]

@shaonialife This PR looks promising and I would love to have this improvement, but before getting this merged, we should have a pref test/benchmarking to show the difference. I can do that when I got some time. Or if you would like to try, please feel free to do so. Thanks!

[shaonialife]

@antfu 仅仅是一个内存占用测试, 没有测试其他项目😊 https://github.com/shaonialife/vue-computed-mem-test

[antfu]

@shaonialife Wow, that's a huge improvement, thanks for your work :)

The code looks good to me, /cc @pikax what do you think?

[pikax]

Also good to me!

Thank you 🚀