下列的 the docs
(Symbol as any).asyncIterator = Symbol.asyncIterator || Symbol.for("Symbol.asyncIterator");
这会导致我的浏览器引发错误:
Uncaught TypeError: Cannot assign to read only property âasyncIteratorâ of function âfunction Symbol() { [native code] }â
由于该属性是只读的,因此仅当它不存在时才对其进行分配:
if (typeof (Symbol as any).asyncIterator === 'undefined') { (Symbol as any).asyncIterator = Symbol.asyncIterator || Symbol('asyncIterator'); }