要求必须是原生的Symbol

[rabit2022]

var $iterator$ = Type.symbol(Symbol.iterator)
    ? Symbol.iterator
    : '_es6-shim iterator_';
fl.trace($iterator$);

我发现 $iterator$ 总是'es6-shim iterator';即使我的环境里面polyfill了Symbol

原因是

var Type = {
    primitive: function (x) {
        return x === null || (typeof x !== 'function' && typeof x !== 'object');
    },
    string: function (x) {
        return _toString(x) === '[object String]';
    },
    regex: function (x) {
        return _toString(x) === '[object RegExp]';
    },
    symbol: function (x) {
        return typeof globals.Symbol === 'function' && typeof x === 'symbol';
    }
};

这里要求必须是原生的Symbol,这里的判断是否过于严格

[ljharb]

I'm not sure why it's overly strict; it wouldn't be wise to trust a different polyfill. What are you using to polyfill Symbol? (noting that Symbol is not actually polyfillable)

[rabit2022]

"symbol-es6"这个库，我已经找到了，怎么配合他的办法。

不信任第三方的Symbol是正确的，感谢解答。

[ljharb]

I’d suggest https://www.npmjs.com/package/get-own-property-symbols; it’s far more widely used.