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这在React代码库中做什么?

reactjs javascript

Ben Aston · 技术社区 · 9 年前

我在React代码库中看到以下内容:

export type TypeOfWork = 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10;

资料来源: https://github.com/facebook/react/blob/master/src/shared/ReactTypeOfWork.js

1 回复 | 直到 9 年前

jantimon 9 年前

这是流或类型脚本语法。

它定义了一个自定义类型,该类型只能是0到10之间的数字。

export type TypeOfWork = 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10;
let x: TypeOfWork = 0;

x = 12; // <-- compiler would throw an error here

https://www.typescriptlang.org/docs/handbook/enums.html

export const enum TypeOfWork {
  IndeterminateComponent = 0, // Before we know whether it is functional or class
  FunctionalComponent = 1,
  ClassComponent = 2,
  HostRoot = 3, // Root of a host tree. Could be nested inside another node.
  HostPortal = 4, // A subtree. Could be an entry point to a different renderer.
  HostComponent = 5,
  HostText = 6,
  CoroutineComponent = 7,
  CoroutineHandlerPhase = 8,
  YieldComponent = 9,
  Fragment = 10
};

正如您在 compiled view