这个 Observablehq 例子中的 "invalidation" 是什么？
What is "invalidation" in this Observablehq example?
https://observablehq.com/@d3/force-directed-lattice?collection=@d3/d3-drag
有一行
invalidation.then(() => simulation.stop());
这个失效是什么？ console.log，这是一个承诺，但我没有看到它在任何地方定义。
Observablehq 加载 standard library, which provides the invalidation 方法。根据文档，invalidation 是...
A promise that resolves when the current cell is re-evaluated: when the cell’s code changes, when it is run using Shift-Enter, or when a referenced input changes.
本笔记本详细解释：https://observablehq.com/@observablehq/invalidation
https://observablehq.com/@d3/force-directed-lattice?collection=@d3/d3-drag
有一行
invalidation.then(() => simulation.stop());
这个失效是什么？ console.log，这是一个承诺，但我没有看到它在任何地方定义。
Observablehq 加载 standard library, which provides the invalidation 方法。根据文档，invalidation 是...
A promise that resolves when the current cell is re-evaluated: when the cell’s code changes, when it is run using Shift-Enter, or when a referenced input changes.
本笔记本详细解释：https://observablehq.com/@observablehq/invalidation