[Suggestion]: render function should be idempotent, not strictly pure

Summary

React docs explain in many instances that render should be pure and you should not read or update refs for this reason, because some features like Suspense can interrupt rendering and restart it.

But from my understanding render can be impure, what matters is that render must be idempotent, meaning interrupting render and calling it again with the same props will always return the same result. The exception given in the docs (using a ref for initialization) works because it is idempotent.

There are many other idempotent but not pure use cases, for example the implementation of what was called useEvent makes use of refs during render but should be fine.

Page

https://react.dev/reference/react/useRef#referencing-a-value-with-a-ref

Details

Change wording of pure to idempotent.

リンクされている React useRef のリファレンスページから始め、レンダーの純粋性と ref の初期化に関する説明を確認します。該当する表現を「pure」から「idempotent」に変更し、その後、ページが中断されたレンダーおよび繰り返されるレンダーに関する要件を正確に説明していることを確認します。