react 源码（1）总览

本文基于 v16.12.0 版本

react 对象

React 暴露出来的 API 如下：

var React = {

    Children: {
      map: mapChildren,
      forEach: forEachChildren,
      count: countChildren,
      toArray: toArray,
      only: onlyChild
    },
    
    createRef: createRef,
    createContext: createContext,
    forwardRef: forwardRef,
    
    Component: Component,
    PureComponent: PureComponent,
    
    lazy: lazy,
    memo: memo,
    
    useCallback: useCallback,
    useContext: useContext,
    useEffect: useEffect,
    useImperativeHandle: useImperativeHandle,
    useDebugValue: useDebugValue,
    useLayoutEffect: useLayoutEffect,
    useMemo: useMemo,
    useReducer: useReducer,
    useRef: useRef,
    useState: useState,
    
    Fragment: REACT_FRAGMENT_TYPE,
    Profiler: REACT_PROFILER_TYPE,
    StrictMode: REACT_STRICT_MODE_TYPE,
    Suspense: REACT_SUSPENSE_TYPE,
    
    createElement: createElementWithValidation,
    cloneElement: cloneElementWithValidation,
    createFactory: createFactoryWithValidation,
    
    isValidElement: isValidElement,
    version: ReactVersion,
    
    __SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED: ReactSharedInternals$2
};