<h3 dir="auto">What problem does this feature solve?</h3>
<p dir="auto">Sorry, the following content is not translated accurately, so use Chinese.</p>
<p dir="auto"><a href="https://jsfiddle.net/_MT_/6zscxLpj/7/" rel="nofollow">Example</a></p>
<p dir="auto">当程序中出现链式计算属性依赖时，我们可能希望的是仅当被依赖的计算属性变更时，它所依赖的计算属性才会重新去计算。而不是因为被依赖的计算属性重新计算链了，所以所有依赖它的计算属性都要重新计算。这样在链式的依赖的计算属性中，可以节省很多计算工作。</p>
<h3 dir="auto">What does the proposed API look like?</h3>
<p dir="auto">仅当被依赖的计算属性变更时，它所依赖的计算属性才会重新去计算。</p>
<h3 dir="auto">Version</h3>
<p dir="auto">2.5.13</p>
<h3 dir="auto">Reproduction link</h3>
<p dir="auto"><a href="https://jsfiddle.net/72gzmayL/" rel="nofollow">https://jsfiddle.net/72gzmayL/</a></p>
<h3 dir="auto">Steps to reproduce</h3>
<p dir="auto">Open the jsfiddle link, see console output.</p>
<h3 dir="auto">What is expected?</h3>
<p dir="auto">Render function isn't called.</p>
<h3 dir="auto">What is actually happening?</h3>
<p dir="auto">Render function is called even when nothing is changed.</p>
<hr>
<p dir="auto">This creates unnecessary render function calls, which leads to performance issues when the component is complex and render function calls aren't cheap.</p>