{"id":644,"date":"2017-03-01T17:40:36","date_gmt":"2017-03-01T09:40:36","guid":{"rendered":"http:\/\/www.qdabc.cn\/?p=644"},"modified":"2017-03-01T23:29:46","modified_gmt":"2017-03-01T15:29:46","slug":"es6%e4%b8%ad%e7%9a%84generator%e5%87%bd%e6%95%b0","status":"publish","type":"post","link":"http:\/\/www.qdabc.cn\/?p=644","title":{"rendered":"ES6\u4e2d\u7684Generator\u51fd\u6570"},"content":{"rendered":"<p><strong>\u5728\u6b64\u5904\u5148\u5217\u4e0b\u672c\u7bc7\u6587\u7ae0\u7684\u4e3b\u8981\u5185\u5bb9<\/strong><\/p>\n<blockquote>\n<ol>\n<li>\u7b80\u4ecb<\/li>\n<li>next\u65b9\u6cd5\u7684\u53c2\u6570<\/li>\n<li>for\u2026of\u5faa\u73af<\/li>\n<li>Generator.prototype.throw()<\/li>\n<li>Generator.prototype.return()<\/li>\n<li>yield* \u8bed\u53e5<\/li>\n<li>\u4f5c\u4e3a\u5bf9\u8c61\u5c5e\u6027\u7684Generator\u51fd\u6570<\/li>\n<li>Generator\u51fd\u6570\u7684this<\/li>\n<li>\u542b\u4e49<\/li>\n<li>\u5e94\u7528<\/li>\n<\/ol>\n<\/blockquote>\n<h2 id=\"\u7b80\u4ecb\"><a name=\"t0\"><\/a>\u7b80\u4ecb<\/h2>\n<hr \/>\n<h4 id=\"\u57fa\u672c\u6982\u5ff5\"><a name=\"t1\"><\/a>\u57fa\u672c\u6982\u5ff5<\/h4>\n<p>Generator \u51fd\u6570\u662f ES6 \u63d0\u4f9b\u7684\u4e00\u79cd\u5f02\u6b65\u7f16\u7a0b\u89e3\u51b3\u65b9\u6848\uff0c\u8bed\u6cd5\u884c\u4e3a\u4e0e\u4f20\u7edf\u51fd\u6570\u5b8c\u5168\u4e0d\u540c\u3002\u672c\u6587\u8be6\u7ec6\u4ecb\u7ecdGenerator \u51fd\u6570\u7684\u8bed\u6cd5\u548c API\uff0c\u6587\u7ae0\u5185\u5bb9\u6709\u70b9\u591a\uff0c\u5927\u5bb6\u53ef\u4ee5\u5f80\u4e0b\u7ffb\uff0c\u53ea\u770b\u81ea\u5df1\u5173\u6ce8\u7684\u70b9\u3002<\/p>\n<p><strong>Generator \u51fd\u6570\u6709\u591a\u79cd\u7406\u89e3\u89d2\u5ea6\u3002\u4ece\u8bed\u6cd5\u4e0a\uff0c\u9996\u5148\u53ef\u4ee5\u628a\u5b83\u7406\u89e3\u6210\uff0cGenerator \u51fd\u6570\u662f\u4e00\u4e2a\u72b6\u6001\u673a\uff0c\u5c01\u88c5\u4e86\u591a\u4e2a\u5185\u90e8\u72b6\u6001\u3002<\/strong><\/p>\n<p>\u6267\u884c Generator \u51fd\u6570\u4f1a\u8fd4\u56de\u4e00\u4e2a\u904d\u5386\u5668\u5bf9\u8c61\uff0c\u4e5f\u5c31\u662f\u8bf4\uff0cGenerator \u51fd\u6570\u9664\u4e86\u72b6\u6001\u673a\uff0c\u8fd8\u662f\u4e00\u4e2a\u904d\u5386\u5668\u5bf9\u8c61\u751f\u6210\u51fd\u6570\u3002\u8fd4\u56de\u7684\u904d\u5386\u5668\u5bf9\u8c61\uff0c\u53ef\u4ee5\u4f9d\u6b21\u904d\u5386 Generator \u51fd\u6570\u5185\u90e8\u7684\u6bcf\u4e00\u4e2a\u72b6\u6001\u3002<\/p>\n<p><strong>\u5f62\u5f0f\u4e0a\uff0cGenerator \u51fd\u6570\u662f\u4e00\u4e2a\u666e\u901a\u51fd\u6570\uff0c\u4f46\u662f\u6709\u4e24\u4e2a\u7279\u5f81\u3002<\/strong><\/p>\n<blockquote>\n<ul>\n<li>function\u5173\u952e\u5b57\u4e0e\u51fd\u6570\u540d\u4e4b\u95f4\u6709\u4e00\u4e2a\u661f\u53f7\uff1b<\/li>\n<li>\u51fd\u6570\u4f53\u5185\u90e8\u4f7f\u7528yield\u8bed\u53e5\uff0c\u5b9a\u4e49\u4e0d\u540c\u7684\u5185\u90e8\u72b6\u6001;<\/li>\n<\/ul>\n<\/blockquote>\n<p>\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n<pre class=\"brush:js;toolbar:false\">function* helloWorldGenerator() {\r\n  yield 'hello';\r\n  yield 'world';\r\n  return 'ending';\r\n}<\/pre>\n<pre class=\"brush:js;toolbar:false\">var hw = helloWorldGenerator();<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u5b9a\u4e49\u4e86\u4e00\u4e2aGenerator\u51fd\u6570helloWorldGenerator\uff0c\u5b83\u5185\u90e8\u6709\u4e24\u4e2ayield\u8bed\u53e5\u201chello\u201d\u548c\u201cworld\u201d\uff0c\u5373\u8be5\u51fd\u6570\u6709\u4e09\u4e2a\u72b6\u6001\uff1ahello\uff0cworld\u548creturn\u8bed\u53e5\uff08\u7ed3\u675f\u6267\u884c\uff09\u3002<\/p>\n<p>Generator\u51fd\u6570\u7684\u8c03\u7528\u65b9\u6cd5\u4e0e\u666e\u901a\u51fd\u6570\u4e00\u6837\uff0c\u4e5f\u662f\u5728\u51fd\u6570\u540d\u540e\u9762\u52a0\u4e0a\u4e00\u5bf9\u5706\u62ec\u53f7\u3002\u4e0d\u540c\u7684\u662f\uff0c\u8c03\u7528Generator\u51fd\u6570\u540e\uff0c\u8be5\u51fd\u6570\u5e76\u4e0d\u6267\u884c\uff0c\u8fd4\u56de\u7684\u4e5f\u4e0d\u662f\u51fd\u6570\u8fd0\u884c\u7ed3\u679c\uff0c\u800c\u662f\u4e00\u4e2a\u6307\u5411\u5185\u90e8\u72b6\u6001\u7684\u6307\u9488\u5bf9\u8c61\uff08\u904d\u5386\u5668\u5bf9\u8c61\uff09\u3002<\/p>\n<p>\u4e0b\u4e00\u6b65\uff0c\u5fc5\u987b\u8c03\u7528\u904d\u5386\u5668\u5bf9\u8c61\u7684next\u65b9\u6cd5\uff0c\u4f7f\u5f97\u6307\u9488\u79fb\u5411\u4e0b\u4e00\u4e2a\u72b6\u6001\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u6bcf\u6b21\u8c03\u7528next\u65b9\u6cd5\uff0c\u5185\u90e8\u6307\u9488\u5c31\u4ece\u51fd\u6570\u5934\u90e8\u6216\u4e0a\u4e00\u6b21\u505c\u4e0b\u6765\u7684\u5730\u65b9\u5f00\u59cb\u6267\u884c\uff0c\u76f4\u5230\u9047\u5230\u4e0b\u4e00\u4e2ayield\u8bed\u53e5\uff08\u6216return\u8bed\u53e5\uff09\u4e3a\u6b62\u3002\u6362\u8a00\u4e4b\uff0cGenerator\u51fd\u6570\u662f\u5206\u6bb5\u6267\u884c\u7684\uff0cyield\u8bed\u53e5\u662f\u6682\u505c\u6267\u884c\u7684\u6807\u8bb0\uff0c\u800cnext\u65b9\u6cd5\u53ef\u4ee5\u6062\u590d\u6267\u884c\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">hw.next()\r\n\/\/ { value: 'hello', done: false }\r\nhw.next()\r\n\/\/ { value: 'world', done: false }\r\nhw.next()\r\n\/\/ { value: 'ending', done: true }\r\nhw.next()\r\n\/\/ { value: undefined, done: true }<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e00\u5171\u8c03\u7528\u4e86\u56db\u6b21<code>next<\/code>\u65b9\u6cd5\u3002<\/p>\n<blockquote><p>\u7b2c\u4e00\u6b21\u8c03\u7528\uff0cGenerator\u51fd\u6570\u5f00\u59cb\u6267\u884c\uff0c\u76f4\u5230\u9047\u5230\u7b2c\u4e00\u4e2a<code>yield<\/code>\u8bed\u53e5\u4e3a\u6b62\u3002<code>next<\/code>\u65b9\u6cd5\u8fd4\u56de\u4e00\u4e2a\u5bf9\u8c61\uff0c\u5b83\u7684<code>value<\/code>\u5c5e\u6027\u5c31\u662f\u5f53\u524d<code>yield<\/code>\u8bed\u53e5\u7684\u503chello\uff0c<code>done<\/code>\u5c5e\u6027\u7684\u503c<code>false<\/code>\uff0c\u8868\u793a\u904d\u5386\u8fd8\u6ca1\u6709\u7ed3\u675f\u3002<\/p>\n<p>\u7b2c\u4e8c\u6b21\u8c03\u7528\uff0cGenerator\u51fd\u6570\u4ece\u4e0a\u6b21<code>yield<\/code>\u8bed\u53e5\u505c\u4e0b\u7684\u5730\u65b9\uff0c\u4e00\u76f4\u6267\u884c\u5230\u4e0b\u4e00\u4e2a<code>yield<\/code>\u8bed\u53e5\u3002<code>next<\/code>\u65b9\u6cd5\u8fd4\u56de\u7684\u5bf9\u8c61\u7684<code>value<\/code>\u5c5e\u6027\u5c31\u662f\u5f53\u524d<code>yield<\/code>\u8bed\u53e5\u7684\u503cworld\uff0c<code>done<\/code>\u5c5e\u6027\u7684\u503c<code>false<\/code>\uff0c\u8868\u793a\u904d\u5386\u8fd8\u6ca1\u6709\u7ed3\u675f\u3002<\/p>\n<p>\u7b2c\u4e09\u6b21\u8c03\u7528\uff0cGenerator\u51fd\u6570\u4ece\u4e0a\u6b21<code>yield<\/code>\u8bed\u53e5\u505c\u4e0b\u7684\u5730\u65b9\uff0c\u4e00\u76f4\u6267\u884c\u5230<code>return<\/code>\u8bed\u53e5\uff08\u5982\u679c\u6ca1\u6709<code>return<\/code>\u8bed\u53e5\uff0c\u5c31\u6267\u884c\u5230\u51fd\u6570\u7ed3\u675f\uff09\u3002<code>next<\/code>\u65b9\u6cd5\u8fd4\u56de\u7684\u5bf9\u8c61\u7684<code>value<\/code>\u5c5e\u6027\uff0c\u5c31\u662f\u7d27\u8ddf\u5728<code>return<\/code>\u8bed\u53e5\u540e\u9762\u7684\u8868\u8fbe\u5f0f\u7684\u503c\uff08\u5982\u679c\u6ca1\u6709<code>return<\/code>\u8bed\u53e5\uff0c\u5219<code>value<\/code>\u5c5e\u6027\u7684\u503c\u4e3a<code>undefined<\/code>\uff09\uff0c<code>done<\/code>\u5c5e\u6027\u7684\u503c<code>true<\/code>\uff0c\u8868\u793a\u904d\u5386\u5df2\u7ecf\u7ed3\u675f\u3002<\/p>\n<p>\u7b2c\u56db\u6b21\u8c03\u7528\uff0c\u6b64\u65f6Generator\u51fd\u6570\u5df2\u7ecf\u8fd0\u884c\u5b8c\u6bd5\uff0c<code>next<\/code>\u65b9\u6cd5\u8fd4\u56de\u5bf9\u8c61\u7684<code>value<\/code>\u5c5e\u6027\u4e3a<code>undefined<\/code>\uff0c<code>done<\/code>\u5c5e\u6027\u4e3a<code>true<\/code>\u3002\u4ee5\u540e\u518d\u8c03\u7528<code>next<\/code>\u65b9\u6cd5\uff0c\u8fd4\u56de\u7684\u90fd\u662f\u8fd9\u4e2a\u503c\u3002<\/p><\/blockquote>\n<p>\u603b\u7ed3\u4e00\u4e0b\uff0c\u8c03\u7528Generator\u51fd\u6570\uff0c\u8fd4\u56de\u4e00\u4e2a\u904d\u5386\u5668\u5bf9\u8c61\uff0c\u4ee3\u8868Generator\u51fd\u6570\u7684\u5185\u90e8\u6307\u9488\u3002\u4ee5\u540e\uff0c\u6bcf\u6b21\u8c03\u7528\u904d\u5386\u5668\u5bf9\u8c61\u7684<code>next<\/code>\u65b9\u6cd5\uff0c\u5c31\u4f1a\u8fd4\u56de\u4e00\u4e2a\u6709\u7740<code>value<\/code>\u548c<code>done<\/code>\u4e24\u4e2a\u5c5e\u6027\u7684\u5bf9\u8c61\u3002<code>value<\/code>\u5c5e\u6027\u8868\u793a\u5f53\u524d\u7684\u5185\u90e8\u72b6\u6001\u7684\u503c\uff0c\u662f<code>yield<\/code>\u8bed\u53e5\u540e\u9762\u90a3\u4e2a\u8868\u8fbe\u5f0f\u7684\u503c\uff1b<code>done<\/code>\u5c5e\u6027\u662f\u4e00\u4e2a\u5e03\u5c14\u503c\uff0c\u8868\u793a\u662f\u5426\u904d\u5386\u7ed3\u675f\u3002<\/p>\n<p><em>ES6\u6ca1\u6709\u89c4\u5b9a\uff0c<code>function<\/code>\u5173\u952e\u5b57\u4e0e\u51fd\u6570\u540d\u4e4b\u95f4\u7684\u661f\u53f7\uff0c\u5199\u5728\u54ea\u4e2a\u4f4d\u7f6e\u3002\u8fd9\u5bfc\u81f4\u4e0b\u9762\u7684\u5199\u6cd5\u90fd\u80fd\u901a\u8fc7\u3002<\/em><\/p>\n<pre class=\"brush:js;toolbar:false\">function * foo(x, y) { \u00b7\u00b7\u00b7 }\r\nfunction *foo(x, y) { \u00b7\u00b7\u00b7 }\r\nfunction* foo(x, y) { \u00b7\u00b7\u00b7 } \/\/\u4e2a\u4eba\u63a8\u8350\u6b64\u5199\u6cd5\r\nfunction*foo(x, y) { \u00b7\u00b7\u00b7 }<\/pre>\n<p>\u7531\u4e8eGenerator\u51fd\u6570\u4ecd\u7136\u662f\u666e\u901a\u51fd\u6570\uff0c\u6240\u4ee5\u4e00\u822c\u7684\u5199\u6cd5\u662f\u4e0a\u9762\u7684\u7b2c\u4e09\u79cd\uff0c\u5373\u661f\u53f7\u7d27\u8ddf\u5728<code>function<\/code>\u5173\u952e\u5b57\u540e\u9762\u3002\u672c\u4e66\u4e5f\u91c7\u7528\u8fd9\u79cd\u5199\u6cd5\u3002<\/p>\n<hr \/>\n<h2 id=\"yield\u8bed\u53e5\"><a name=\"t2\"><\/a>yield\u8bed\u53e5<\/h2>\n<p>\u7531\u4e8eGenerator\u51fd\u6570\u8fd4\u56de\u7684\u904d\u5386\u5668\u5bf9\u8c61\uff0c\u53ea\u6709\u8c03\u7528<code>next<\/code>\u65b9\u6cd5\u624d\u4f1a\u904d\u5386\u4e0b\u4e00\u4e2a\u5185\u90e8\u72b6\u6001\uff0c\u6240\u4ee5\u5176\u5b9e\u63d0\u4f9b\u4e86\u4e00\u79cd\u53ef\u4ee5\u6682\u505c\u6267\u884c\u7684\u51fd\u6570\u3002<code>yield<\/code>\u8bed\u53e5\u5c31\u662f\u6682\u505c\u6807\u5fd7\u3002<\/p>\n<p>\u904d\u5386\u5668\u5bf9\u8c61\u7684<code>next<\/code>\u65b9\u6cd5\u7684\u8fd0\u884c\u903b\u8f91\u5982\u4e0b\u3002<\/p>\n<blockquote>\n<ol>\n<li>\u9047\u5230<code>yield<\/code>\u8bed\u53e5\uff0c\u5c31\u6682\u505c\u6267\u884c\u540e\u9762\u7684\u64cd\u4f5c\uff0c\u5e76\u5c06\u7d27\u8ddf\u5728<code>yield<\/code>\u540e\u9762\u7684\u90a3\u4e2a\u8868\u8fbe\u5f0f\u7684\u503c\uff0c\u4f5c\u4e3a\u8fd4\u56de\u7684\u5bf9\u8c61\u7684<code>value<\/code>\u5c5e\u6027\u503c\u3002<\/li>\n<li>\u4e0b\u4e00\u6b21\u8c03\u7528<code>next<\/code>\u65b9\u6cd5\u65f6\uff0c\u518d\u7ee7\u7eed\u5f80\u4e0b\u6267\u884c\uff0c\u76f4\u5230\u9047\u5230\u4e0b\u4e00\u4e2a<code>yield<\/code>\u8bed\u53e5\u3002<\/li>\n<li>\u5982\u679c\u6ca1\u6709\u518d\u9047\u5230\u65b0\u7684<code>yield<\/code>\u8bed\u53e5\uff0c\u5c31\u4e00\u76f4\u8fd0\u884c\u5230\u51fd\u6570\u7ed3\u675f\uff0c\u76f4\u5230<code>return<\/code>\u8bed\u53e5\u4e3a\u6b62\uff0c\u5e76\u5c06<code>return<\/code>\u8bed\u53e5\u540e\u9762\u7684\u8868\u8fbe\u5f0f\u7684\u503c\uff0c\u4f5c\u4e3a\u8fd4\u56de\u7684\u5bf9\u8c61\u7684<code>value<\/code>\u5c5e\u6027\u503c\u3002<\/li>\n<li>\u5982\u679c\u8be5\u51fd\u6570\u6ca1\u6709<code>return<\/code>\u8bed\u53e5\uff0c\u5219\u8fd4\u56de\u7684\u5bf9\u8c61\u7684<code>value<\/code>\u5c5e\u6027\u503c\u4e3a<code>undefined<\/code>\u3002<\/li>\n<\/ol>\n<\/blockquote>\n<p>\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c<code>yield<\/code>\u8bed\u53e5\u540e\u9762\u7684\u8868\u8fbe\u5f0f\uff0c\u53ea\u6709\u5f53\u8c03\u7528<code>next<\/code>\u65b9\u6cd5\u3001\u5185\u90e8\u6307\u9488\u6307\u5411\u8be5\u8bed\u53e5\u65f6\u624d\u4f1a\u6267\u884c\uff0c\u56e0\u6b64\u7b49\u4e8e\u4e3aJavaScript\u63d0\u4f9b\u4e86\u624b\u52a8\u7684\u201c\u60f0\u6027\u6c42\u503c\u201d\uff08Lazy Evaluation\uff09\u7684\u8bed\u6cd5\u529f\u80fd\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* gen() {\r\n  yield  123 + 456;\r\n}<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c<code>yield<\/code>\u540e\u9762\u7684\u8868\u8fbe\u5f0f123 + 456\uff0c\u4e0d\u4f1a\u7acb\u5373\u6c42\u503c\uff0c\u53ea\u4f1a\u5728<code>next<\/code>\u65b9\u6cd5\u5c06\u6307\u9488\u79fb\u5230\u8fd9\u4e00\u53e5\u65f6\uff0c\u624d\u4f1a\u6c42\u503c\u3002<\/p>\n<hr \/>\n<p><code>yield<\/code>\u8bed\u53e5\u4e0e<code>return<\/code>\u8bed\u53e5\u65e2\u6709\u76f8\u4f3c\u4e4b\u5904\uff0c\u4e5f\u6709\u533a\u522b\u3002\u76f8\u4f3c\u4e4b\u5904\u5728\u4e8e\uff0c\u90fd\u80fd\u8fd4\u56de\u7d27\u8ddf\u5728\u8bed\u53e5\u540e\u9762\u7684\u90a3\u4e2a\u8868\u8fbe\u5f0f\u7684\u503c\u3002\u533a\u522b\u5728\u4e8e\u6bcf\u6b21\u9047\u5230<code>yield<\/code>\uff0c\u51fd\u6570\u6682\u505c\u6267\u884c\uff0c\u4e0b\u4e00\u6b21\u518d\u4ece\u8be5\u4f4d\u7f6e\u7ee7\u7eed\u5411\u540e\u6267\u884c\uff0c\u800c<code>return<\/code>\u8bed\u53e5\u4e0d\u5177\u5907\u4f4d\u7f6e\u8bb0\u5fc6\u7684\u529f\u80fd\u3002\u4e00\u4e2a\u51fd\u6570\u91cc\u9762\uff0c\u53ea\u80fd\u6267\u884c\u4e00\u6b21\uff08\u6216\u8005\u8bf4\u4e00\u4e2a\uff09<code>return<\/code>\u8bed\u53e5\uff0c\u4f46\u662f\u53ef\u4ee5\u6267\u884c\u591a\u6b21\uff08\u6216\u8005\u8bf4\u591a\u4e2a\uff09<code>yield<\/code>\u8bed\u53e5\u3002\u6b63\u5e38\u51fd\u6570\u53ea\u80fd\u8fd4\u56de\u4e00\u4e2a\u503c\uff0c\u56e0\u4e3a\u53ea\u80fd\u6267\u884c\u4e00\u6b21<code>return<\/code>\uff1bGenerator\u51fd\u6570\u53ef\u4ee5\u8fd4\u56de\u4e00\u7cfb\u5217\u7684\u503c\uff0c\u56e0\u4e3a\u53ef\u4ee5\u6709\u4efb\u610f\u591a\u4e2a<code>yield<\/code>\u3002\u4ece\u53e6\u4e00\u4e2a\u89d2\u5ea6\u770b\uff0c\u4e5f\u53ef\u4ee5\u8bf4Generator\u751f\u6210\u4e86\u4e00\u7cfb\u5217\u7684\u503c\uff0c\u8fd9\u4e5f\u5c31\u662f\u5b83\u7684\u540d\u79f0\u7684\u6765\u5386\uff08\u5728\u82f1\u8bed\u4e2d\uff0cgenerator\u8fd9\u4e2a\u8bcd\u662f\u201c\u751f\u6210\u5668\u201d\u7684\u610f\u601d\uff09\u3002<\/p>\n<p>Generator\u51fd\u6570\u53ef\u4ee5\u4e0d\u7528<code>yield<\/code>\u8bed\u53e5\uff0c\u8fd9\u65f6\u5c31\u53d8\u6210\u4e86\u4e00\u4e2a\u5355\u7eaf\u7684\u6682\u7f13\u6267\u884c\u51fd\u6570\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">\u200bfunction* f() {\r\n  console.log('\u6267\u884c\u4e86\uff01')\r\n}\r\nvar generator = f();\r\nsetTimeout(function () {\r\n  generator.next()\r\n}, 2000);<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c\u51fd\u6570f\u5982\u679c\u662f\u666e\u901a\u51fd\u6570\uff0c\u5728\u4e3a\u53d8\u91cfgenerator\u8d4b\u503c\u65f6\u5c31\u4f1a\u6267\u884c\u3002\u4f46\u662f\uff0c\u51fd\u6570f\u662f\u4e00\u4e2a Generator \u51fd\u6570\uff0c\u5c31\u53d8\u6210\u53ea\u6709\u8c03\u7528<code>next<\/code>\u65b9\u6cd5\u65f6\uff0c\u51fd\u6570f\u624d\u4f1a\u6267\u884c\u3002<\/p>\n<p><strong>\u53e6\u5916\u9700\u8981\u6ce8\u610f\uff0c<code>yield<\/code>\u8bed\u53e5\u53ea\u80fd\u7528\u5728 Generator \u51fd\u6570\u91cc\u9762\uff0c\u7528\u5728\u5176\u4ed6\u5730\u65b9\u90fd\u4f1a\u62a5\u9519\u3002<\/strong><\/p>\n<pre class=\"brush:js;toolbar:false\">(function (){\r\n  yield 1;\r\n})()\r\n\/\/ Uncaught SyntaxError: Unexpected number<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u5728\u4e00\u4e2a\u666e\u901a\u51fd\u6570\u4e2d\u4f7f\u7528<code>yield<\/code>\u8bed\u53e5\uff0c\u7ed3\u679c\u4ea7\u751f\u4e00\u4e2a\u53e5\u6cd5\u9519\u8bef\u3002<\/p>\n<p>\u4e0b\u9762\u662f\u53e6\u5916\u4e00\u4e2a\u4f8b\u5b50\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">\u200bvar arr = [1, [[2, 3], 4], [5, 6]];\r\nvar flat = function* (a) {\r\n  a.forEach(function (item) {\r\n    if (typeof item !== 'number') {\r\n      yield* flat(item);\r\n    } else {\r\n      yield item;\r\n    }\r\n  }\r\n};\r\nfor (var f of flat(arr)){\r\n  console.log(f);\r\n}<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e5f\u4f1a\u4ea7\u751f\u53e5\u6cd5\u9519\u8bef\uff0c\u56e0\u4e3a<code>forEach<\/code>\u65b9\u6cd5\u7684\u53c2\u6570\u662f\u4e00\u4e2a\u666e\u901a\u51fd\u6570\uff0c\u4f46\u662f\u5728\u91cc\u9762\u4f7f\u7528\u4e86<code>yield<\/code>\u8bed\u53e5\uff08\u8fd9\u4e2a\u51fd\u6570\u91cc\u9762\u8fd8\u4f7f\u7528\u4e86yield*\u8bed\u53e5\uff0c\u8be6\u7ec6\u4ecb\u7ecd\u89c1\u540e\u6587\uff09\u3002\u4e00\u79cd\u4fee\u6539\u65b9\u6cd5\u662f\u6539\u7528<code>for<\/code>\u5faa\u73af\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">var arr = [1, [[2, 3], 4], [5, 6]];\r\nvar flat = function* (a) {\r\n  var length = a.length;\r\n  for (var i = 0; i &lt; length; i++) {\r\n    var item = a[i];\r\n    if (typeof item !== 'number') {\r\n      yield* flat(item);\r\n    } else {\r\n      yield item;\r\n    }\r\n  }\r\n};\r\nfor (var f of flat(arr)) {\r\n  console.log(f);\r\n}\r\n\/\/ 1, 2, 3, 4, 5, 6<\/pre>\n<p>\u53e6\u5916\uff0c<code>yield<\/code>\u8bed\u53e5\u5982\u679c\u7528\u5728\u4e00\u4e2a\u8868\u8fbe\u5f0f\u4e4b\u4e2d\uff0c\u5fc5\u987b\u653e\u5728\u5706\u62ec\u53f7\u91cc\u9762\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* demo() {\r\n  console.log('Hello' + yield); \/\/ SyntaxError\r\n  console.log('Hello' + yield 123); \/\/ SyntaxError\r\n  console.log('Hello' + (yield)); \/\/ OK\r\n  console.log('Hello' + (yield 123)); \/\/ OK\r\n}<\/pre>\n<p><code>yield<\/code>\u8bed\u53e5\u7528\u4f5c\u51fd\u6570\u53c2\u6570\u6216\u653e\u5728\u8d4b\u503c\u8868\u8fbe\u5f0f\u7684\u53f3\u8fb9\uff0c\u53ef\u4ee5\u4e0d\u52a0\u62ec\u53f7\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* demo() {\r\n  foo(yield 'a', yield 'b'); \/\/ OK\r\n  let input = yield; \/\/ OK\r\n}<\/pre>\n<h2 id=\"\u4e0e-iterator-\u63a5\u53e3\u7684\u5173\u7cfb\">\u4e0e Iterator \u63a5\u53e3\u7684\u5173\u7cfb<\/h2>\n<p>\u4efb\u610f\u4e00\u4e2a\u5bf9\u8c61\u7684Symbol.iterator\u65b9\u6cd5\uff0c\u7b49\u4e8e\u8be5\u5bf9\u8c61\u7684\u904d\u5386\u5668\u751f\u6210\u51fd\u6570\uff0c\u8c03\u7528\u8be5\u51fd\u6570\u4f1a\u8fd4\u56de\u8be5\u5bf9\u8c61\u7684\u4e00\u4e2a\u904d\u5386\u5668\u5bf9\u8c61\u3002<\/p>\n<p>\u7531\u4e8eGenerator\u51fd\u6570\u5c31\u662f\u904d\u5386\u5668\u751f\u6210\u51fd\u6570\uff0c\u56e0\u6b64\u53ef\u4ee5\u628aGenerator\u8d4b\u503c\u7ed9\u5bf9\u8c61\u7684Symbol.iterator\u5c5e\u6027\uff0c\u4ece\u800c\u4f7f\u5f97\u8be5\u5bf9\u8c61\u5177\u6709Iterator\u63a5\u53e3\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">var myIterable = {};\r\nmyIterable[Symbol.iterator] = function* () {\r\n  yield 1;\r\n  yield 2;\r\n  yield 3;\r\n};\r\n\r\n[...myIterable] \/\/ [1, 2, 3]<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0cGenerator\u51fd\u6570\u8d4b\u503c\u7ed9<code>Symbol.iterator<\/code>\u5c5e\u6027\uff0c\u4ece\u800c\u4f7f\u5f97<code>myIterable<\/code>\u5bf9\u8c61\u5177\u6709\u4e86<code>Iterator<\/code>\u63a5\u53e3\uff0c\u53ef\u4ee5\u88ab<code>...<\/code>\u8fd0\u7b97\u7b26\u904d\u5386\u4e86\u3002<\/p>\n<p>Generator\u51fd\u6570\u6267\u884c\u540e\uff0c\u8fd4\u56de\u4e00\u4e2a\u904d\u5386\u5668\u5bf9\u8c61\u3002\u8be5\u5bf9\u8c61\u672c\u8eab\u4e5f\u5177\u6709<code>Symbol.iterator<\/code>\u5c5e\u6027\uff0c\u6267\u884c\u540e\u8fd4\u56de\u81ea\u8eab\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">\u200bfunction* gen(){\r\n  \/\/ some code\r\n}\r\nvar g = gen();\r\ng[Symbol.iterator]() === g\r\n\/\/ true<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c<code>gen<\/code>\u662f\u4e00\u4e2aGenerator\u51fd\u6570\uff0c\u8c03\u7528\u5b83\u4f1a\u751f\u6210\u4e00\u4e2a\u904d\u5386\u5668\u5bf9\u8c61<code>g<\/code>\u3002\u5b83\u7684<code>Symbol.iterator<\/code>\u5c5e\u6027\uff0c\u4e5f\u662f\u4e00\u4e2a\u904d\u5386\u5668\u5bf9\u8c61\u751f\u6210\u51fd\u6570\uff0c\u6267\u884c\u540e\u8fd4\u56de\u5b83\u81ea\u5df1\u3002<\/p>\n<hr \/>\n<h2 id=\"next\u65b9\u6cd5\u7684\u53c2\u6570\"><a name=\"t4\"><\/a>next\u65b9\u6cd5\u7684\u53c2\u6570<\/h2>\n<p><code>yield<\/code>\u53e5\u672c\u8eab\u6ca1\u6709\u8fd4\u56de\u503c\uff0c\u6216\u8005\u8bf4\u603b\u662f\u8fd4\u56de<code>undefined<\/code>\u3002<code>next<\/code>\u65b9\u6cd5\u53ef\u4ee5\u5e26\u4e00\u4e2a\u53c2\u6570\uff0c\u8be5\u53c2\u6570\u5c31\u4f1a\u88ab\u5f53\u4f5c\u4e0a\u4e00\u4e2a<code>yield<\/code>\u8bed\u53e5\u7684\u8fd4\u56de\u503c\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* f() {\r\n  for(var i = 0; true; i++) {\r\n    var reset = yield i;\r\n    if(reset) { i = -1; }\r\n  }\r\n}\r\nvar g = f();\r\ng.next() \/\/ { value: 0, done: false }\r\ng.next() \/\/ { value: 1, done: false }\r\ng.next(true) \/\/ { value: 0, done: false }<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u5148\u5b9a\u4e49\u4e86\u4e00\u4e2a\u53ef\u4ee5\u65e0\u9650\u8fd0\u884c\u7684 Generator \u51fd\u6570<code>f<\/code>\uff0c\u5982\u679c<code>next<\/code>\u65b9\u6cd5\u6ca1\u6709\u53c2\u6570\uff0c\u6bcf\u6b21\u8fd0\u884c\u5230<code>yield<\/code>\u8bed\u53e5\uff0c\u53d8\u91cf<code>reset<\/code>\u7684\u503c\u603b\u662f<code>undefined<\/code>\u3002\u5f53<code>next<\/code>\u65b9\u6cd5\u5e26\u4e00\u4e2a\u53c2\u6570<code>true<\/code>\u65f6\uff0c\u53d8\u91cf<code>reset<\/code>\u5c31\u88ab\u91cd\u7f6e\u4e3a\u8fd9\u4e2a\u53c2\u6570\uff08\u5373<code>true<\/code>\uff09\uff0c\u56e0\u6b64<code>i<\/code>\u4f1a\u7b49\u4e8e<code>-1<\/code>\uff0c\u4e0b\u4e00\u8f6e\u5faa\u73af\u5c31\u4f1a\u4ece<code>-1<\/code>\u5f00\u59cb\u9012\u589e\u3002<\/p>\n<p>\u8fd9\u4e2a\u529f\u80fd\u6709\u5f88\u91cd\u8981\u7684\u8bed\u6cd5\u610f\u4e49\u3002Generator \u51fd\u6570\u4ece\u6682\u505c\u72b6\u6001\u5230\u6062\u590d\u8fd0\u884c\uff0c\u5b83\u7684\u4e0a\u4e0b\u6587\u72b6\u6001\uff08context\uff09\u662f\u4e0d\u53d8\u7684\u3002\u901a\u8fc7<code>next<\/code>\u65b9\u6cd5\u7684\u53c2\u6570\uff0c\u5c31\u6709\u529e\u6cd5\u5728 Generator \u51fd\u6570\u5f00\u59cb\u8fd0\u884c\u4e4b\u540e\uff0c\u7ee7\u7eed\u5411\u51fd\u6570\u4f53\u5185\u90e8\u6ce8\u5165\u503c\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u53ef\u4ee5\u5728 Generator \u51fd\u6570\u8fd0\u884c\u7684\u4e0d\u540c\u9636\u6bb5\uff0c\u4ece\u5916\u90e8\u5411\u5185\u90e8\u6ce8\u5165\u4e0d\u540c\u7684\u503c\uff0c\u4ece\u800c\u8c03\u6574\u51fd\u6570\u884c\u4e3a\u3002<\/p>\n<p>\u518d\u770b\u4e00\u4e2a\u4f8b\u5b50\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* foo(x) {\r\n  var y = 2 * (yield (x + 1));\r\n  var z = yield (y \/ 3);\r\n  return (x + y + z);\r\n}\r\nvar a = foo(5);\r\na.next() \/\/ Object{value:6, done:false}\r\na.next() \/\/ Object{value:NaN, done:false}\r\na.next() \/\/ Object{value:NaN, done:true}\r\nvar b = foo(5);\r\nb.next() \/\/ { value:6, done:false }\r\nb.next(12) \/\/ { value:8, done:false }\r\nb.next(13) \/\/ { value:42, done:true }<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c\u7b2c\u4e8c\u6b21\u8fd0\u884c<code>next<\/code>\u65b9\u6cd5\u7684\u65f6\u5019\u4e0d\u5e26\u53c2\u6570\uff0c\u5bfc\u81f4y\u7684\u503c\u7b49\u4e8e<code>2 * undefined<\/code>\uff08\u5373<code>NaN<\/code>\uff09\uff0c\u9664\u4ee53\u4ee5\u540e\u8fd8\u662f<code>NaN<\/code>\uff0c\u56e0\u6b64\u8fd4\u56de\u5bf9\u8c61\u7684<code>value<\/code>\u5c5e\u6027\u4e5f\u7b49\u4e8e<code>NaN<\/code>\u3002\u7b2c\u4e09\u6b21\u8fd0\u884c<code>Next<\/code>\u65b9\u6cd5\u7684\u65f6\u5019\u4e0d\u5e26\u53c2\u6570\uff0c\u6240\u4ee5<code>z<\/code>\u7b49\u4e8e<code>undefined<\/code>\uff0c\u8fd4\u56de\u5bf9\u8c61\u7684<code>value<\/code>\u5c5e\u6027\u7b49\u4e8e<code>5 + NaN + undefined<\/code>\uff0c\u5373<code>NaN<\/code>\u3002<\/p>\n<p>\u5982\u679c\u5411<code>next<\/code>\u65b9\u6cd5\u63d0\u4f9b\u53c2\u6570\uff0c\u8fd4\u56de\u7ed3\u679c\u5c31\u5b8c\u5168\u4e0d\u4e00\u6837\u4e86\u3002\u4e0a\u9762\u4ee3\u7801\u7b2c\u4e00\u6b21\u8c03\u7528<code>b<\/code>\u7684<code>next<\/code>\u65b9\u6cd5\u65f6\uff0c\u8fd4\u56de<code>x+1<\/code>\u7684\u503c6\uff1b\u7b2c\u4e8c\u6b21\u8c03\u7528<code>next<\/code>\u65b9\u6cd5\uff0c\u5c06\u4e0a\u4e00\u6b21<code>yield<\/code>\u8bed\u53e5\u7684\u503c\u8bbe\u4e3a12\uff0c\u56e0\u6b64<code>y<\/code>\u7b49\u4e8e24\uff0c\u8fd4\u56de<code>y \/ 3<\/code>\u7684\u503c8\uff1b\u7b2c\u4e09\u6b21\u8c03\u7528<code>next<\/code>\u65b9\u6cd5\uff0c\u5c06\u4e0a\u4e00\u6b21<code>yield<\/code>\u8bed\u53e5\u7684\u503c\u8bbe\u4e3a13\uff0c\u56e0\u6b64<code>z<\/code>\u7b49\u4e8e13\uff0c\u8fd9\u65f6<code>x<\/code>\u7b49\u4e8e5\uff0c<code>y<\/code>\u7b49\u4e8e24\uff0c\u6240\u4ee5<code>return<\/code>\u8bed\u53e5\u7684\u503c\u7b49\u4e8e42\u3002<\/p>\n<p>\u6ce8\u610f\uff0c\u7531\u4e8e<code>next<\/code>\u65b9\u6cd5\u7684\u53c2\u6570\u8868\u793a\u4e0a\u4e00\u4e2a<code>yield<\/code>\u8bed\u53e5\u7684\u8fd4\u56de\u503c\uff0c\u6240\u4ee5\u7b2c\u4e00\u6b21\u4f7f\u7528<code>next<\/code>\u65b9\u6cd5\u65f6\uff0c\u4e0d\u80fd\u5e26\u6709\u53c2\u6570\u3002V8\u5f15\u64ce\u76f4\u63a5\u5ffd\u7565\u7b2c\u4e00\u6b21\u4f7f\u7528<code>next<\/code>\u65b9\u6cd5\u65f6\u7684\u53c2\u6570\uff0c\u53ea\u6709\u4ece\u7b2c\u4e8c\u6b21\u4f7f\u7528<code>next<\/code>\u65b9\u6cd5\u5f00\u59cb\uff0c\u53c2\u6570\u624d\u662f\u6709\u6548\u7684\u3002\u4ece\u8bed\u4e49\u4e0a\u8bb2\uff0c\u7b2c\u4e00\u4e2a<code>next<\/code>\u65b9\u6cd5\u7528\u6765\u542f\u52a8\u904d\u5386\u5668\u5bf9\u8c61\uff0c\u6240\u4ee5\u4e0d\u7528\u5e26\u6709\u53c2\u6570\u3002<\/p>\n<p>\u5982\u679c\u60f3\u8981\u7b2c\u4e00\u6b21\u8c03\u7528<code>next<\/code>\u65b9\u6cd5\u65f6\uff0c\u5c31\u80fd\u591f\u8f93\u5165\u503c\uff0c\u53ef\u4ee5\u5728Generator\u51fd\u6570\u5916\u9762\u518d\u5305\u4e00\u5c42\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function wrapper(generatorFunction) {\r\n  return function (...args) {\r\n    let generatorObject = generatorFunction(...args);\r\n    generatorObject.next();\r\n    return generatorObject;\r\n  };\r\n}\r\nconst wrapped = wrapper(function* () {\r\n  console.log(`First input: ${yield}`);\r\n  return 'DONE';\r\n});\r\nwrapped().next('hello!')\r\n\/\/ First input: hello!<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0cGenerator\u51fd\u6570\u5982\u679c\u4e0d\u7528<code>wrapper<\/code>\u5148\u5305\u4e00\u5c42\uff0c\u662f\u65e0\u6cd5\u7b2c\u4e00\u6b21\u8c03\u7528<code>next<\/code>\u65b9\u6cd5\uff0c\u5c31\u8f93\u5165\u53c2\u6570\u7684\u3002<\/p>\n<p>\u518d\u770b\u4e00\u4e2a\u901a\u8fc7<code>next<\/code>\u65b9\u6cd5\u7684\u53c2\u6570\uff0c\u5411Generator\u51fd\u6570\u5185\u90e8\u8f93\u5165\u503c\u7684\u4f8b\u5b50\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* dataConsumer() {\r\n  console.log('Started');\r\n  console.log(`1. ${yield}`);\r\n  console.log(`2. ${yield}`);\r\n  return 'result';\r\n}\r\n\r\nlet genObj = dataConsumer();\r\ngenObj.next();\r\n\/\/ Started\r\ngenObj.next('a')\r\n\/\/ 1. a\r\ngenObj.next('b')\r\n\/\/ 2. b<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u662f\u4e00\u4e2a\u5f88\u76f4\u89c2\u7684\u4f8b\u5b50\uff0c\u6bcf\u6b21\u901a\u8fc7<code>next<\/code>\u65b9\u6cd5\u5411Generator\u51fd\u6570\u8f93\u5165\u503c\uff0c\u7136\u540e\u6253\u5370\u51fa\u6765\u3002<\/p>\n<h2 id=\"forof\u5faa\u73af\"><a name=\"t5\"><\/a>for\u2026of\u5faa\u73af<\/h2>\n<p><code>for...of<\/code>\u5faa\u73af\u53ef\u4ee5\u81ea\u52a8\u904d\u5386Generator\u51fd\u6570\u65f6\u751f\u6210\u7684<code>Iterator<\/code>\u5bf9\u8c61\uff0c\u4e14\u6b64\u65f6\u4e0d\u518d\u9700\u8981\u8c03\u7528<code>next<\/code>\u65b9\u6cd5\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function *foo() {\r\n  yield 1;\r\n  yield 2;\r\n  yield 3;\r\n  yield 4;\r\n  yield 5;\r\n  return 6;\r\n}\r\nfor (let v of foo()) {\r\n  console.log(v);\r\n}\r\n\/\/ 1 2 3 4 5<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4f7f\u7528<code>for...of<\/code>\u5faa\u73af\uff0c\u4f9d\u6b21\u663e\u793a5\u4e2a<code>yield<\/code>\u8bed\u53e5\u7684\u503c\u3002\u8fd9\u91cc\u9700\u8981\u6ce8\u610f\uff0c\u4e00\u65e6<code>next<\/code>\u65b9\u6cd5\u7684\u8fd4\u56de\u5bf9\u8c61\u7684<code>done<\/code>\u5c5e\u6027\u4e3a<code>true<\/code>\uff0c<code>for...of<\/code>\u5faa\u73af\u5c31\u4f1a\u4e2d\u6b62\uff0c\u4e14\u4e0d\u5305\u542b\u8be5\u8fd4\u56de\u5bf9\u8c61\uff0c\u6240\u4ee5\u4e0a\u9762\u4ee3\u7801\u7684<code>return<\/code>\u8bed\u53e5\u8fd4\u56de\u76846\uff0c\u4e0d\u5305\u62ec\u5728<code>for...of<\/code>\u5faa\u73af\u4e4b\u4e2d\u3002<\/p>\n<p>\u4e0b\u9762\u662f\u4e00\u4e2a\u5229\u7528Generator\u51fd\u6570\u548c<code>for...of<\/code>\u5faa\u73af\uff0c\u5b9e\u73b0\u6590\u6ce2\u90a3\u5951\u6570\u5217\u7684\u4f8b\u5b50\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* fibonacci() {\r\n  let [prev, curr] = [0, 1];\r\n  for (;;) {\r\n    [prev, curr] = [curr, prev + curr];\r\n    yield curr;\r\n  }\r\n}\r\nfor (let n of fibonacci()) {\r\n  if (n &gt; 1000) break;\r\n  console.log(n);\r\n}<\/pre>\n<p>\u4ece\u4e0a\u9762\u4ee3\u7801\u53ef\u89c1\uff0c\u4f7f\u7528<code>for...of<\/code>\u8bed\u53e5\u65f6\u4e0d\u9700\u8981\u4f7f\u7528<code>next<\/code>\u65b9\u6cd5\u3002<\/p>\n<p>\u5229\u7528<code>for...of<\/code>\u5faa\u73af\uff0c\u53ef\u4ee5\u5199\u51fa\u904d\u5386\u4efb\u610f\u5bf9\u8c61\uff08object\uff09\u7684\u65b9\u6cd5\u3002\u539f\u751f\u7684JavaScript\u5bf9\u8c61\u6ca1\u6709\u904d\u5386\u63a5\u53e3\uff0c\u65e0\u6cd5\u4f7f\u7528<code>for...of<\/code>\u5faa\u73af\uff0c\u901a\u8fc7Generator\u51fd\u6570\u4e3a\u5b83\u52a0\u4e0a\u8fd9\u4e2a\u63a5\u53e3\uff0c\u5c31\u53ef\u4ee5\u7528\u4e86\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* objectEntries(obj) {\r\n  let propKeys = Reflect.ownKeys(obj);\r\n\r\n  for (let propKey of propKeys) {\r\n    yield [propKey, obj[propKey]];\r\n  }\r\n}\r\nlet jane = { first: 'Jane', last: 'Doe' };\r\nfor (let [key, value] of objectEntries(jane)) {\r\n  console.log(`${key}: ${value}`);\r\n}\r\n\/\/ first: Jane\r\n\/\/ last: Doe<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c\u5bf9\u8c61<code>jane<\/code>\u539f\u751f\u4e0d\u5177\u5907Iterator\u63a5\u53e3\uff0c\u65e0\u6cd5\u7528<code>for...of<\/code>\u904d\u5386\u3002\u8fd9\u65f6\uff0c\u6211\u4eec\u901a\u8fc7Generator\u51fd\u6570<code>objectEntries<\/code>\u4e3a\u5b83\u52a0\u4e0a\u904d\u5386\u5668\u63a5\u53e3\uff0c\u5c31\u53ef\u4ee5\u7528<code>for...of<\/code>\u904d\u5386\u4e86\u3002\u52a0\u4e0a\u904d\u5386\u5668\u63a5\u53e3\u7684\u53e6\u4e00\u79cd\u5199\u6cd5\u662f\uff0c\u5c06Generator\u51fd\u6570\u52a0\u5230\u5bf9\u8c61\u7684<code>Symbol.iterator<\/code>\u5c5e\u6027\u4e0a\u9762\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* objectEntries() {\r\n  let propKeys = Object.keys(this);\r\n\r\n  for (let propKey of propKeys) {\r\n    yield [propKey, this[propKey]];\r\n  }\r\n}\r\nlet jane = { first: 'Jane', last: 'Doe' };\r\njane[Symbol.iterator] = objectEntries;\r\nfor (let [key, value] of jane) {\r\n  console.log(`${key}: ${value}`);\r\n}\r\n\/\/ first: Jane\r\n\/\/ last: Doe<\/pre>\n<p>\u9664\u4e86<code>for...of<\/code>\u5faa\u73af\u4ee5\u5916\uff0c\u6269\u5c55\u8fd0\u7b97\u7b26\uff08<code>...<\/code>\uff09\u3001\u89e3\u6784\u8d4b\u503c\u548c<code>Array.from<\/code>\u65b9\u6cd5\u5185\u90e8\u8c03\u7528\u7684\uff0c\u90fd\u662f\u904d\u5386\u5668\u63a5\u53e3\u3002\u8fd9\u610f\u5473\u7740\uff0c\u5b83\u4eec\u90fd\u53ef\u4ee5\u5c06Generator\u51fd\u6570\u8fd4\u56de\u7684Iterator\u5bf9\u8c61\uff0c\u4f5c\u4e3a\u53c2\u6570\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* numbers () {\r\n  yield 1\r\n  yield 2\r\n  return 3\r\n  yield 4\r\n}\r\n\/\/ \u6269\u5c55\u8fd0\u7b97\u7b26\r\n[...numbers()] \/\/ [1, 2]\r\n\/\/ Array.from \u65b9\u6cd5\r\nArray.from(numbers()) \/\/ [1, 2]\r\n\/\/ \u89e3\u6784\u8d4b\u503c\r\nlet [x, y] = numbers();\r\nx \/\/ 1\r\ny \/\/ 2\r\n\/\/ for...of \u5faa\u73af\r\nfor (let n of numbers()) {\r\n  console.log(n)\r\n}\r\n\/\/ 1\r\n\/\/ 2<\/pre>\n<h2 id=\"generatorprototypethrow\">Generator.prototype.throw()<\/h2>\n<p>Generator\u51fd\u6570\u8fd4\u56de\u7684\u904d\u5386\u5668\u5bf9\u8c61\uff0c\u90fd\u6709\u4e00\u4e2a<code>throw<\/code>\u65b9\u6cd5\uff0c\u53ef\u4ee5\u5728\u51fd\u6570\u4f53\u5916\u629b\u51fa\u9519\u8bef\uff0c\u7136\u540e\u5728Generator\u51fd\u6570\u4f53\u5185\u6355\u83b7\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">var g = function* () {\r\n  try {\r\n    yield;\r\n  } catch (e) {\r\n    console.log('\u5185\u90e8\u6355\u83b7', e);\r\n  }\r\n};\r\nvar i = g();\r\ni.next();\r\ntry {\r\n  i.throw('a');\r\n  i.throw('b');\r\n} catch (e) {\r\n  console.log('\u5916\u90e8\u6355\u83b7', e);\r\n}\r\n\/\/ \u5185\u90e8\u6355\u83b7 a\r\n\/\/ \u5916\u90e8\u6355\u83b7 b<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c\u904d\u5386\u5668\u5bf9\u8c61<code>i<\/code>\u8fde\u7eed\u629b\u51fa\u4e24\u4e2a\u9519\u8bef\u3002\u7b2c\u4e00\u4e2a\u9519\u8bef\u88abGenerator\u51fd\u6570\u4f53\u5185\u7684<code>catch<\/code>\u8bed\u53e5\u6355\u83b7\u3002<code>i<\/code>\u7b2c\u4e8c\u6b21\u629b\u51fa\u9519\u8bef\uff0c\u7531\u4e8eGenerator\u51fd\u6570\u5185\u90e8\u7684<code>catch<\/code>\u8bed\u53e5\u5df2\u7ecf\u6267\u884c\u8fc7\u4e86\uff0c\u4e0d\u4f1a\u518d\u6355\u6349\u5230\u8fd9\u4e2a\u9519\u8bef\u4e86\uff0c\u6240\u4ee5\u8fd9\u4e2a\u9519\u8bef\u5c31\u88ab\u629b\u51fa\u4e86Generator\u51fd\u6570\u4f53\uff0c\u88ab\u51fd\u6570\u4f53\u5916\u7684<code>catch<\/code>\u8bed\u53e5\u6355\u83b7\u3002<\/p>\n<p><code>throw<\/code>\u65b9\u6cd5\u53ef\u4ee5\u63a5\u53d7\u4e00\u4e2a\u53c2\u6570\uff0c\u8be5\u53c2\u6570\u4f1a\u88ab<code>catch<\/code>\u8bed\u53e5\u63a5\u6536\uff0c\u5efa\u8bae\u629b\u51fa<code>Error<\/code>\u5bf9\u8c61\u7684\u5b9e\u4f8b\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">var g = function* () {\r\n  try {\r\n    yield;\r\n  } catch (e) {\r\n    console.log(e);\r\n  }\r\n};\r\nvar i = g();\r\ni.next();\r\ni.throw(new Error('\u51fa\u9519\u4e86\uff01'));\r\n\/\/ Error: \u51fa\u9519\u4e86\uff01(\u2026)<\/pre>\n<p>\u6ce8\u610f\uff0c\u4e0d\u8981\u6df7\u6dc6\u904d\u5386\u5668\u5bf9\u8c61\u7684<code>throw<\/code>\u65b9\u6cd5\u548c\u5168\u5c40\u7684<code>throw<\/code>\u547d\u4ee4\u3002\u4e0a\u9762\u4ee3\u7801\u7684\u9519\u8bef\uff0c\u662f\u7528\u904d\u5386\u5668\u5bf9\u8c61\u7684<code>throw<\/code>\u65b9\u6cd5\u629b\u51fa\u7684\uff0c\u800c\u4e0d\u662f\u7528<code>throw<\/code>\u547d\u4ee4\u629b\u51fa\u7684\u3002\u540e\u8005\u53ea\u80fd\u88ab\u51fd\u6570\u4f53\u5916\u7684<code>catch<\/code>\u8bed\u53e5\u6355\u83b7\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">var g = function* () {\r\n  while (true) {\r\n    try {\r\n      yield;\r\n    } catch (e) {\r\n      if (e != 'a') throw e;\r\n      console.log('\u5185\u90e8\u6355\u83b7', e);\r\n    }\r\n  }\r\n};\r\nvar i = g();\r\ni.next();\r\ntry {\r\n  throw new Error('a');\r\n  throw new Error('b');\r\n} catch (e) {\r\n  console.log('\u5916\u90e8\u6355\u83b7', e);\r\n}\r\n\/\/ \u5916\u90e8\u6355\u83b7 [Error: a]<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e4b\u6240\u4ee5\u53ea\u6355\u83b7\u4e86<code>a<\/code>\uff0c\u662f\u56e0\u4e3a\u51fd\u6570\u4f53\u5916\u7684<code>catch<\/code>\u8bed\u53e5\u5757\uff0c\u6355\u83b7\u4e86\u629b\u51fa\u7684<code>a<\/code>\u9519\u8bef\u4ee5\u540e\uff0c\u5c31\u4e0d\u4f1a\u518d\u7ee7\u7eed<code>try<\/code>\u4ee3\u7801\u5757\u91cc\u9762\u5269\u4f59\u7684\u8bed\u53e5\u4e86\u3002<\/p>\n<p>\u5982\u679cGenerator\u51fd\u6570\u5185\u90e8\u6ca1\u6709\u90e8\u7f72<code>try...catch<\/code>\u4ee3\u7801\u5757\uff0c\u90a3\u4e48<code>throw<\/code>\u65b9\u6cd5\u629b\u51fa\u7684\u9519\u8bef\uff0c\u5c06\u88ab\u5916\u90e8<code>try...catch<\/code>\u4ee3\u7801\u5757\u6355\u83b7\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">var g = function* () {\r\n  while (true) {\r\n    yield;\r\n    console.log('\u5185\u90e8\u6355\u83b7', e);\r\n  }\r\n};\r\nvar i = g();\r\ni.next();\r\ntry {\r\n  i.throw('a');\r\n  i.throw('b');\r\n} catch (e) {\r\n  console.log('\u5916\u90e8\u6355\u83b7', e);\r\n}\r\n\/\/ \u5916\u90e8\u6355\u83b7 a<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0cGenerator\u51fd\u6570<code>g<\/code>\u5185\u90e8\u6ca1\u6709\u90e8\u7f72<code>try...catch<\/code>\u4ee3\u7801\u5757\uff0c\u6240\u4ee5\u629b\u51fa\u7684\u9519\u8bef\u76f4\u63a5\u88ab\u5916\u90e8<code>catch<\/code>\u4ee3\u7801\u5757\u6355\u83b7\u3002<\/p>\n<p>\u5982\u679cGenerator\u51fd\u6570\u5185\u90e8\u548c\u5916\u90e8\uff0c\u90fd\u6ca1\u6709\u90e8\u7f72<code>try...catch<\/code>\u4ee3\u7801\u5757\uff0c\u90a3\u4e48\u7a0b\u5e8f\u5c06\u62a5\u9519\uff0c\u76f4\u63a5\u4e2d\u65ad\u6267\u884c\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">\u200bvar gen = function* gen(){\r\n  yield console.log('hello');\r\n  yield console.log('world');\r\n}\r\nvar g = gen();\r\ng.next();\r\ng.throw();\r\n\/\/ hello\r\n\/\/ Uncaught undefined<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c<code>g.throw<\/code>\u629b\u51fa\u9519\u8bef\u4ee5\u540e\uff0c\u6ca1\u6709\u4efb\u4f55<code>try...catch<\/code>\u4ee3\u7801\u5757\u53ef\u4ee5\u6355\u83b7\u8fd9\u4e2a\u9519\u8bef\uff0c\u5bfc\u81f4\u7a0b\u5e8f\u62a5\u9519\uff0c\u4e2d\u65ad\u6267\u884c\u3002<\/p>\n<p><code>throw<\/code>\u65b9\u6cd5\u88ab\u6355\u83b7\u4ee5\u540e\uff0c\u4f1a\u9644\u5e26\u6267\u884c\u4e0b\u4e00\u6761<code>yield<\/code>\u8bed\u53e5\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u4f1a\u9644\u5e26\u6267\u884c\u4e00\u6b21<code>next<\/code>\u65b9\u6cd5\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">var gen = function* gen(){\r\n  try {\r\n    yield console.log('a');\r\n  } catch (e) {\r\n    \/\/ ...\r\n  }\r\n  yield console.log('b');\r\n  yield console.log('c');\r\n}\r\nvar g = gen();\r\ng.next() \/\/ a\r\ng.throw() \/\/ b\r\ng.next() \/\/ c<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c<code>g.throw<\/code>\u65b9\u6cd5\u88ab\u6355\u83b7\u4ee5\u540e\uff0c\u81ea\u52a8\u6267\u884c\u4e86\u4e00\u6b21<code>next<\/code>\u65b9\u6cd5\uff0c\u6240\u4ee5\u4f1a\u6253\u5370<code>b<\/code>\u3002\u53e6\u5916\uff0c\u4e5f\u53ef\u4ee5\u770b\u5230\uff0c\u53ea\u8981Generator\u51fd\u6570\u5185\u90e8\u90e8\u7f72\u4e86<code>try...catch<\/code>\u4ee3\u7801\u5757\uff0c\u90a3\u4e48\u904d\u5386\u5668\u7684<code>throw<\/code>\u65b9\u6cd5\u629b\u51fa\u7684\u9519\u8bef\uff0c\u4e0d\u5f71\u54cd\u4e0b\u4e00\u6b21\u904d\u5386\u3002<\/p>\n<p>\u53e6\u5916\uff0c<code>throw<\/code>\u547d\u4ee4\u4e0e<code>g.throw<\/code>\u65b9\u6cd5\u662f\u65e0\u5173\u7684\uff0c\u4e24\u8005\u4e92\u4e0d\u5f71\u54cd\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">\u200bvar gen = function* gen(){\r\n  yield console.log('hello');\r\n  yield console.log('world');\r\n}\r\nvar g = gen();\r\ng.next();\r\ntry {\r\n  throw new Error();\r\n} catch (e) {\r\n  g.next();\r\n}\r\n\/\/ hello\r\n\/\/ world<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c<code>throw<\/code>\u547d\u4ee4\u629b\u51fa\u7684\u9519\u8bef\u4e0d\u4f1a\u5f71\u54cd\u5230\u904d\u5386\u5668\u7684\u72b6\u6001\uff0c\u6240\u4ee5\u4e24\u6b21\u6267\u884c<code>next<\/code>\u65b9\u6cd5\uff0c\u90fd\u8fdb\u884c\u4e86\u6b63\u786e\u7684\u64cd\u4f5c\u3002<\/p>\n<p>\u8fd9\u79cd\u51fd\u6570\u4f53\u5185\u6355\u83b7\u9519\u8bef\u7684\u673a\u5236\uff0c\u5927\u5927\u65b9\u4fbf\u4e86\u5bf9\u9519\u8bef\u7684\u5904\u7406\u3002\u591a\u4e2a<code>yield<\/code>\u8bed\u53e5\uff0c\u53ef\u4ee5\u53ea\u7528\u4e00\u4e2a<code>try...catch<\/code>\u4ee3\u7801\u5757\u6765\u6355\u83b7\u9519\u8bef\u3002\u5982\u679c\u4f7f\u7528\u56de\u8c03\u51fd\u6570\u7684\u5199\u6cd5\uff0c\u60f3\u8981\u6355\u83b7\u591a\u4e2a\u9519\u8bef\uff0c\u5c31\u4e0d\u5f97\u4e0d\u4e3a\u6bcf\u4e2a\u51fd\u6570\u5185\u90e8\u5199\u4e00\u4e2a\u9519\u8bef\u5904\u7406\u8bed\u53e5\uff0c\u73b0\u5728\u53ea\u5728Generator\u51fd\u6570\u5185\u90e8\u5199\u4e00\u6b21<code>catch<\/code>\u8bed\u53e5\u5c31\u53ef\u4ee5\u4e86\u3002<\/p>\n<p>Generator\u51fd\u6570\u4f53\u5916\u629b\u51fa\u7684\u9519\u8bef\uff0c\u53ef\u4ee5\u5728\u51fd\u6570\u4f53\u5185\u6355\u83b7\uff1b\u53cd\u8fc7\u6765\uff0cGenerator\u51fd\u6570\u4f53\u5185\u629b\u51fa\u7684\u9519\u8bef\uff0c\u4e5f\u53ef\u4ee5\u88ab\u51fd\u6570\u4f53\u5916\u7684<code>catch<\/code>\u6355\u83b7\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function *foo() {\r\n  var x = yield 3;\r\n  var y = x.toUpperCase();\r\n  yield y;\r\n}\r\nvar it = foo();\r\nit.next(); \/\/ { value:3, done:false }\r\ntry {\r\n  it.next(42);\r\n} catch (err) {\r\n  console.log(err);\r\n}<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c\u7b2c\u4e8c\u4e2a<code>next<\/code>\u65b9\u6cd5\u5411\u51fd\u6570\u4f53\u5185\u4f20\u5165\u4e00\u4e2a\u53c2\u657042\uff0c\u6570\u503c\u662f\u6ca1\u6709<code>toUpperCase<\/code>\u65b9\u6cd5\u7684\uff0c\u6240\u4ee5\u4f1a\u629b\u51fa\u4e00\u4e2aTypeError\u9519\u8bef\uff0c\u88ab\u51fd\u6570\u4f53\u5916\u7684<code>catch<\/code>\u6355\u83b7\u3002<\/p>\n<p>\u4e00\u65e6Generator\u6267\u884c\u8fc7\u7a0b\u4e2d\u629b\u51fa\u9519\u8bef\uff0c\u4e14\u6ca1\u6709\u88ab\u5185\u90e8\u6355\u83b7\uff0c\u5c31\u4e0d\u4f1a\u518d\u6267\u884c\u4e0b\u53bb\u4e86\u3002\u5982\u679c\u6b64\u540e\u8fd8\u8c03\u7528<code>next<\/code>\u65b9\u6cd5\uff0c\u5c06\u8fd4\u56de\u4e00\u4e2a<code>value<\/code>\u5c5e\u6027\u7b49\u4e8e<code>undefined<\/code>\u3001<code>done<\/code>\u5c5e\u6027\u7b49\u4e8e<code>true<\/code>\u7684\u5bf9\u8c61\uff0c\u5373JavaScript\u5f15\u64ce\u8ba4\u4e3a\u8fd9\u4e2aGenerator\u5df2\u7ecf\u8fd0\u884c\u7ed3\u675f\u4e86\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* g() {\r\n  yield 1;\r\n  console.log('throwing an exception');\r\n  throw new Error('generator broke!');\r\n  yield 2;\r\n  yield 3;\r\n}\r\nfunction log(generator) {\r\n  var v;\r\n  console.log('starting generator');\r\n  try {\r\n    v = generator.next();\r\n    console.log('\u7b2c\u4e00\u6b21\u8fd0\u884cnext\u65b9\u6cd5', v);\r\n  } catch (err) {\r\n    console.log('\u6355\u6349\u9519\u8bef', v);\r\n  }\r\n  try {\r\n    v = generator.next();\r\n    console.log('\u7b2c\u4e8c\u6b21\u8fd0\u884cnext\u65b9\u6cd5', v);\r\n  } catch (err) {\r\n    console.log('\u6355\u6349\u9519\u8bef', v);\r\n  }\r\n  try {\r\n    v = generator.next();\r\n    console.log('\u7b2c\u4e09\u6b21\u8fd0\u884cnext\u65b9\u6cd5', v);\r\n  } catch (err) {\r\n    console.log('\u6355\u6349\u9519\u8bef', v);\r\n  }\r\n  console.log('caller done');\r\n}\r\nlog(g());\r\n\/\/ starting generator\r\n\/\/ \u7b2c\u4e00\u6b21\u8fd0\u884cnext\u65b9\u6cd5 { value: 1, done: false }\r\n\/\/ throwing an exception\r\n\/\/ \u6355\u6349\u9519\u8bef { value: 1, done: false }\r\n\/\/ \u7b2c\u4e09\u6b21\u8fd0\u884cnext\u65b9\u6cd5 { value: undefined, done: true }\r\n\/\/ caller done<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e00\u5171\u4e09\u6b21\u8fd0\u884c<code>next<\/code>\u65b9\u6cd5\uff0c\u7b2c\u4e8c\u6b21\u8fd0\u884c\u7684\u65f6\u5019\u4f1a\u629b\u51fa\u9519\u8bef\uff0c\u7136\u540e\u7b2c\u4e09\u6b21\u8fd0\u884c\u7684\u65f6\u5019\uff0cGenerator\u51fd\u6570\u5c31\u5df2\u7ecf\u7ed3\u675f\u4e86\uff0c\u4e0d\u518d\u6267\u884c\u4e0b\u53bb\u4e86\u3002<\/p>\n<h2 id=\"generatorprototypereturn\"><a name=\"t7\"><\/a>Generator.prototype.return()<\/h2>\n<p>Generator\u51fd\u6570\u8fd4\u56de\u7684\u904d\u5386\u5668\u5bf9\u8c61\uff0c\u8fd8\u6709\u4e00\u4e2a<code>return<\/code>\u65b9\u6cd5\uff0c\u53ef\u4ee5\u8fd4\u56de\u7ed9\u5b9a\u7684\u503c\uff0c\u5e76\u4e14\u7ec8\u7ed3\u904d\u5386Generator\u51fd\u6570\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* gen() {\r\n  yield 1;\r\n  yield 2;\r\n  yield 3;\r\n}\r\nvar g = gen();\r\ng.next()        \/\/ { value: 1, done: false }\r\ng.return('foo') \/\/ { value: \"foo\", done: true }\r\ng.next()        \/\/ { value: undefined, done: true }<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c\u904d\u5386\u5668\u5bf9\u8c61<code>g<\/code>\u8c03\u7528<code>return<\/code>\u65b9\u6cd5\u540e\uff0c\u8fd4\u56de\u503c\u7684<code>value<\/code>\u5c5e\u6027\u5c31\u662f<code>return<\/code>\u65b9\u6cd5\u7684\u53c2\u6570<code>foo<\/code>\u3002\u5e76\u4e14\uff0cGenerator\u51fd\u6570\u7684\u904d\u5386\u5c31\u7ec8\u6b62\u4e86\uff0c\u8fd4\u56de\u503c\u7684<code>done<\/code>\u5c5e\u6027\u4e3a<code>true<\/code>\uff0c\u4ee5\u540e\u518d\u8c03\u7528<code>next<\/code>\u65b9\u6cd5\uff0c<code>done<\/code>\u5c5e\u6027\u603b\u662f\u8fd4\u56de<code>true<\/code>\u3002<\/p>\n<p>\u5982\u679c<code>return<\/code>\u65b9\u6cd5\u8c03\u7528\u65f6\uff0c\u4e0d\u63d0\u4f9b\u53c2\u6570\uff0c\u5219\u8fd4\u56de\u503c\u7684<code>value<\/code>\u5c5e\u6027\u4e3a<code>undefined<\/code>\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* gen() {\r\n  yield 1;\r\n  yield 2;\r\n  yield 3;\r\n}\r\nvar g = gen();\r\ng.next()        \/\/ { value: 1, done: false }\r\ng.return() \/\/ { value: undefined, done: true }<\/pre>\n<p>\u5982\u679cGenerator\u51fd\u6570\u5185\u90e8\u6709<code>try...finally<\/code>\u4ee3\u7801\u5757\uff0c\u90a3\u4e48<code>return<\/code>\u65b9\u6cd5\u4f1a\u63a8\u8fdf\u5230<code>finally<\/code>\u4ee3\u7801\u5757\u6267\u884c\u5b8c\u518d\u6267\u884c\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* numbers () {\r\n  yield 1;\r\n  try {\r\n    yield 2;\r\n    yield 3;\r\n  } finally {\r\n    yield 4;\r\n    yield 5;\r\n  }\r\n  yield 6;\r\n}\r\nvar g = numbers()\r\ng.next() \/\/ { done: false, value: 1 }\r\ng.next() \/\/ { done: false, value: 2 }\r\ng.return(7) \/\/ { done: false, value: 4 }\r\ng.next() \/\/ { done: false, value: 5 }\r\ng.next() \/\/ { done: true, value: 7 }<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c\u8c03\u7528<code>return<\/code>\u65b9\u6cd5\u540e\uff0c\u5c31\u5f00\u59cb\u6267\u884c<code>finally<\/code>\u4ee3\u7801\u5757\uff0c\u7136\u540e\u7b49\u5230<code>finally<\/code>\u4ee3\u7801\u5757\u6267\u884c\u5b8c\uff0c\u518d\u6267\u884c<code>return<\/code>\u65b9\u6cd5\u3002<\/p>\n<h2 id=\"yield-\u8bed\u53e5\"><a name=\"t8\"><\/a>yield* \u8bed\u53e5<\/h2>\n<p>\u5982\u679c\u5728 Generator \u51fd\u6570\u5185\u90e8\uff0c\u8c03\u7528\u53e6\u4e00\u4e2a Generator \u51fd\u6570\uff0c\u9ed8\u8ba4\u60c5\u51b5\u4e0b\u662f\u6ca1\u6709\u6548\u679c\u7684\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* foo() {\r\n  yield 'a';\r\n  yield 'b';\r\n}\r\nfunction* bar() {\r\n  yield 'x';\r\n  foo();\r\n  yield 'y';\r\n}\r\nfor (let v of bar()){\r\n  console.log(v);\r\n}\r\n\/\/ \"x\"\r\n\/\/ \"y\"<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c<code>foo<\/code>\u548c<code>bar<\/code>\u90fd\u662f Generator \u51fd\u6570\uff0c\u5728<code>bar<\/code>\u91cc\u9762\u8c03\u7528<code>foo<\/code>\uff0c\u662f\u4e0d\u4f1a\u6709\u6548\u679c\u7684\u3002<\/p>\n<p>\u8fd9\u4e2a\u5c31\u9700\u8981\u7528\u5230<code>yield*<\/code>\u8bed\u53e5\uff0c\u7528\u6765\u5728\u4e00\u4e2a Generator \u51fd\u6570\u91cc\u9762\u6267\u884c\u53e6\u4e00\u4e2a Generator \u51fd\u6570\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* bar() {\r\n  yield 'x';\r\n  yield* foo();\r\n  yield 'y';\r\n}\r\n\r\n\/\/ \u7b49\u540c\u4e8e\r\nfunction* bar() {\r\n  yield 'x';\r\n  yield 'a';\r\n  yield 'b';\r\n  yield 'y';\r\n}\r\n\r\n\/\/ \u7b49\u540c\u4e8e\r\nfunction* bar() {\r\n  yield 'x';\r\n  for (let v of foo()) {\r\n    yield v;\r\n  }\r\n  yield 'y';\r\n}\r\n\r\nfor (let v of bar()){\r\n  console.log(v);\r\n}\r\n\/\/ \"x\"\r\n\/\/ \"a\"\r\n\/\/ \"b\"\r\n\/\/ \"y\"<\/pre>\n<p>\u518d\u6765\u770b\u4e00\u4e2a\u5bf9\u6bd4\u7684\u4f8b\u5b50\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* inner() {\r\n  yield 'hello!';\r\n}\r\n\r\nfunction* outer1() {\r\n  yield 'open';\r\n  yield inner();\r\n  yield 'close';\r\n}\r\n\r\nvar gen = outer1()\r\ngen.next().value \/\/ \"open\"\r\ngen.next().value \/\/ \u8fd4\u56de\u4e00\u4e2a\u904d\u5386\u5668\u5bf9\u8c61\r\ngen.next().value \/\/ \"close\"\r\n\r\nfunction* outer2() {\r\n  yield 'open'\r\n  yield* inner()\r\n  yield 'close'\r\n}\r\n\r\nvar gen = outer2()\r\ngen.next().value \/\/ \"open\"\r\ngen.next().value \/\/ \"hello!\"\r\ngen.next().value \/\/ \"close\"<\/pre>\n<p>\u4e0a\u9762\u4f8b\u5b50\u4e2d\uff0c<code>outer2<\/code>\u4f7f\u7528\u4e86<code>yield*<\/code>\uff0c<code>outer1<\/code>\u6ca1\u4f7f\u7528\u3002\u7ed3\u679c\u5c31\u662f\uff0c<code>outer1<\/code>\u8fd4\u56de\u4e00\u4e2a\u904d\u5386\u5668\u5bf9\u8c61\uff0c<code>outer2<\/code>\u8fd4\u56de\u8be5\u904d\u5386\u5668\u5bf9\u8c61\u7684\u5185\u90e8\u503c\u3002<\/p>\n<p>\u4ece\u8bed\u6cd5\u89d2\u5ea6\u770b\uff0c\u5982\u679c<code>yield<\/code>\u547d\u4ee4\u540e\u9762\u8ddf\u7684\u662f\u4e00\u4e2a\u904d\u5386\u5668\u5bf9\u8c61\uff0c\u9700\u8981\u5728<code>yield<\/code>\u547d\u4ee4\u540e\u9762\u52a0\u4e0a\u661f\u53f7\uff0c\u8868\u660e\u5b83\u8fd4\u56de\u7684\u662f\u4e00\u4e2a\u904d\u5386\u5668\u5bf9\u8c61\u3002\u8fd9\u88ab\u79f0\u4e3a<code>yield*<\/code>\u8bed\u53e5\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">let delegatedIterator = (function* () {\r\n  yield 'Hello!';\r\n  yield 'Bye!';\r\n}());\r\n\r\nlet delegatingIterator = (function* () {\r\n  yield 'Greetings!';\r\n  yield* delegatedIterator;\r\n  yield 'Ok, bye.';\r\n}());\r\n\r\nfor(let value of delegatingIterator) {\r\n  console.log(value);\r\n}\r\n\/\/ \"Greetings!\r\n\/\/ \"Hello!\"\r\n\/\/ \"Bye!\"\r\n\/\/ \"Ok, bye.\"<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c<code>delegatingIterator<\/code>\u662f\u4ee3\u7406\u8005\uff0c<code>delegatedIterator<\/code>\u662f\u88ab\u4ee3\u7406\u8005\u3002\u7531\u4e8e<code>yield* delegatedIterator<\/code>\u8bed\u53e5\u5f97\u5230\u7684\u503c\uff0c\u662f\u4e00\u4e2a\u904d\u5386\u5668\uff0c\u6240\u4ee5\u8981\u7528\u661f\u53f7\u8868\u793a\u3002\u8fd0\u884c\u7ed3\u679c\u5c31\u662f\u4f7f\u7528\u4e00\u4e2a\u904d\u5386\u5668\uff0c\u904d\u5386\u4e86\u591a\u4e2aGenerator\u51fd\u6570\uff0c\u6709\u9012\u5f52\u7684\u6548\u679c\u3002<\/p>\n<p><code>yield*<\/code>\u540e\u9762\u7684Generator\u51fd\u6570\uff08\u6ca1\u6709<code>return<\/code>\u8bed\u53e5\u65f6\uff09\uff0c\u7b49\u540c\u4e8e\u5728Generator\u51fd\u6570\u5185\u90e8\uff0c\u90e8\u7f72\u4e00\u4e2a<code>for...of<\/code>\u5faa\u73af\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* concat(iter1, iter2) {\r\n  yield* iter1;\r\n  yield* iter2;\r\n}\r\n\r\n\/\/ \u7b49\u540c\u4e8e\r\n\r\nfunction* concat(iter1, iter2) {\r\n  for (var value of iter1) {\r\n    yield value;\r\n  }\r\n  for (var value of iter2) {\r\n    yield value;\r\n  }\r\n}<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u8bf4\u660e\uff0c<code>yield*<\/code>\u540e\u9762\u7684Generator\u51fd\u6570\uff08\u6ca1\u6709<code>return<\/code>\u8bed\u53e5\u65f6\uff09\uff0c\u4e0d\u8fc7\u662f<code>for...of<\/code>\u7684\u4e00\u79cd\u7b80\u5199\u5f62\u5f0f\uff0c\u5b8c\u5168\u53ef\u4ee5\u7528\u540e\u8005\u66ff\u4ee3\u524d\u8005\u3002\u53cd\u4e4b\uff0c\u5219\u9700\u8981\u7528<code>var value = yield* iterator<\/code>\u7684\u5f62\u5f0f\u83b7\u53d6<code>return<\/code>\u8bed\u53e5\u7684\u503c\u3002<\/p>\n<p>\u5982\u679c<code>yield*<\/code>\u540e\u9762\u8ddf\u7740\u4e00\u4e2a\u6570\u7ec4\uff0c\u7531\u4e8e\u6570\u7ec4\u539f\u751f\u652f\u6301\u904d\u5386\u5668\uff0c\u56e0\u6b64\u5c31\u4f1a\u904d\u5386\u6570\u7ec4\u6210\u5458\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* gen(){\r\n  yield* [\"a\", \"b\", \"c\"];\r\n}\r\ngen().next() \/\/ { value:\"a\", done:false }<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c<code>yield<\/code>\u547d\u4ee4\u540e\u9762\u5982\u679c\u4e0d\u52a0\u661f\u53f7\uff0c\u8fd4\u56de\u7684\u662f\u6574\u4e2a\u6570\u7ec4\uff0c\u52a0\u4e86\u661f\u53f7\u5c31\u8868\u793a\u8fd4\u56de\u7684\u662f\u6570\u7ec4\u7684\u904d\u5386\u5668\u5bf9\u8c61\u3002<\/p>\n<p>\u5b9e\u9645\u4e0a\uff0c\u4efb\u4f55\u6570\u636e\u7ed3\u6784\u53ea\u8981\u6709Iterator\u63a5\u53e3\uff0c\u5c31\u53ef\u4ee5\u88ab<code>yield*<\/code>\u904d\u5386\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">let read = (function* () {\r\n  yield 'hello';\r\n  yield* 'hello';\r\n})();\r\n\r\nread.next().value \/\/ \"hello\"\r\nread.next().value \/\/ \"h\"<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c<code>yield<\/code>\u8bed\u53e5\u8fd4\u56de\u6574\u4e2a\u5b57\u7b26\u4e32\uff0c<code>yield*<\/code>\u8bed\u53e5\u8fd4\u56de\u5355\u4e2a\u5b57\u7b26\u3002\u56e0\u4e3a\u5b57\u7b26\u4e32\u5177\u6709Iterator\u63a5\u53e3\uff0c\u6240\u4ee5\u88ab<code>yield*<\/code>\u904d\u5386\u3002<\/p>\n<p>\u5982\u679c\u88ab\u4ee3\u7406\u7684Generator\u51fd\u6570\u6709<code>return<\/code>\u8bed\u53e5\uff0c\u90a3\u4e48\u5c31\u53ef\u4ee5\u5411\u4ee3\u7406\u5b83\u7684Generator\u51fd\u6570\u8fd4\u56de\u6570\u636e\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function *foo() {\r\n  yield 2;\r\n  yield 3;\r\n  return \"foo\";\r\n}\r\n\r\nfunction *bar() {\r\n  yield 1;\r\n  var v = yield *foo();\r\n  console.log( \"v: \" + v );\r\n  yield 4;\r\n}\r\n\r\nvar it = bar();\r\n\r\nit.next()\r\n\/\/ {value: 1, done: false}\r\nit.next()\r\n\/\/ {value: 2, done: false}\r\nit.next()\r\n\/\/ {value: 3, done: false}\r\nit.next();\r\n\/\/ \"v: foo\"\r\n\/\/ {value: 4, done: false}\r\nit.next()\r\n\/\/ {value: undefined, done: true}<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u5728\u7b2c\u56db\u6b21\u8c03\u7528<code>next<\/code>\u65b9\u6cd5\u7684\u65f6\u5019\uff0c\u5c4f\u5e55\u4e0a\u4f1a\u6709\u8f93\u51fa\uff0c\u8fd9\u662f\u56e0\u4e3a\u51fd\u6570<code>foo<\/code>\u7684<code>return<\/code>\u8bed\u53e5\uff0c\u5411\u51fd\u6570<code>bar<\/code>\u63d0\u4f9b\u4e86\u8fd4\u56de\u503c\u3002<\/p>\n<p>\u518d\u770b\u4e00\u4e2a\u4f8b\u5b50\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* genFuncWithReturn() {\r\n  yield 'a';\r\n  yield 'b';\r\n  return 'The result';\r\n}\r\nfunction* logReturned(genObj) {\r\n  let result = yield* genObj;\r\n  console.log(result);\r\n}\r\n\r\n[...logReturned(genFuncWithReturn())]\r\n\/\/ The result\r\n\/\/ \u503c\u4e3a [ 'a', 'b' ]<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c\u5b58\u5728\u4e24\u6b21\u904d\u5386\u3002\u7b2c\u4e00\u6b21\u662f\u6269\u5c55\u8fd0\u7b97\u7b26\u904d\u5386\u51fd\u6570<code>logReturned<\/code>\u8fd4\u56de\u7684\u904d\u5386\u5668\u5bf9\u8c61\uff0c\u7b2c\u4e8c\u6b21\u662f<code>yield*<\/code>\u8bed\u53e5\u904d\u5386\u51fd\u6570<code>genFuncWithReturn<\/code>\u8fd4\u56de\u7684\u904d\u5386\u5668\u5bf9\u8c61\u3002\u8fd9\u4e24\u6b21\u904d\u5386\u7684\u6548\u679c\u662f\u53e0\u52a0\u7684\uff0c\u6700\u7ec8\u8868\u73b0\u4e3a\u6269\u5c55\u8fd0\u7b97\u7b26\u904d\u5386\u51fd\u6570<code>genFuncWithReturn<\/code>\u8fd4\u56de\u7684\u904d\u5386\u5668\u5bf9\u8c61\u3002\u6240\u4ee5\uff0c\u6700\u540e\u7684\u6570\u636e\u8868\u8fbe\u5f0f\u5f97\u5230\u7684\u503c\u7b49\u4e8e<code>[ 'a', 'b' ]<\/code>\u3002\u4f46\u662f\uff0c\u51fd\u6570<code>genFuncWithReturn<\/code>\u7684<code>return<\/code>\u8bed\u53e5\u7684\u8fd4\u56de\u503c<code>The result<\/code>\uff0c\u4f1a\u8fd4\u56de\u7ed9\u51fd\u6570<code>logReturned<\/code>\u5185\u90e8\u7684<code>result<\/code>\u53d8\u91cf\uff0c\u56e0\u6b64\u4f1a\u6709\u7ec8\u7aef\u8f93\u51fa\u3002<\/p>\n<p><code>yield*<\/code>\u547d\u4ee4\u53ef\u4ee5\u5f88\u65b9\u4fbf\u5730\u53d6\u51fa\u5d4c\u5957\u6570\u7ec4\u7684\u6240\u6709\u6210\u5458\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* iterTree(tree) {\r\n  if (Array.isArray(tree)) {\r\n    for(let i=0; i &lt; tree.length; i++) {\r\n      yield* iterTree(tree[i]);\r\n    }\r\n  } else {\r\n    yield tree;\r\n  }\r\n}\r\n\r\nconst tree = [ 'a', ['b', 'c'], ['d', 'e'] ];\r\n\r\nfor(let x of iterTree(tree)) {\r\n  console.log(x);\r\n}\r\n\/\/ a\r\n\/\/ b\r\n\/\/ c\r\n\/\/ d\r\n\/\/ e<\/pre>\n<p>\u4e0b\u9762\u662f\u4e00\u4e2a\u7a0d\u5fae\u590d\u6742\u7684\u4f8b\u5b50\uff0c\u4f7f\u7528<code>yield*<\/code>\u8bed\u53e5\u904d\u5386\u5b8c\u5168\u4e8c\u53c9\u6811\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">\/\/ \u4e0b\u9762\u662f\u4e8c\u53c9\u6811\u7684\u6784\u9020\u51fd\u6570\uff0c\r\n\/\/ \u4e09\u4e2a\u53c2\u6570\u5206\u522b\u662f\u5de6\u6811\u3001\u5f53\u524d\u8282\u70b9\u548c\u53f3\u6811\r\nfunction Tree(left, label, right) {\r\n  this.left = left;\r\n  this.label = label;\r\n  this.right = right;\r\n}\r\n\r\n\/\/ \u4e0b\u9762\u662f\u4e2d\u5e8f\uff08inorder\uff09\u904d\u5386\u51fd\u6570\u3002\r\n\/\/ \u7531\u4e8e\u8fd4\u56de\u7684\u662f\u4e00\u4e2a\u904d\u5386\u5668\uff0c\u6240\u4ee5\u8981\u7528generator\u51fd\u6570\u3002\r\n\/\/ \u51fd\u6570\u4f53\u5185\u91c7\u7528\u9012\u5f52\u7b97\u6cd5\uff0c\u6240\u4ee5\u5de6\u6811\u548c\u53f3\u6811\u8981\u7528yield*\u904d\u5386\r\nfunction* inorder(t) {\r\n  if (t) {\r\n    yield* inorder(t.left);\r\n    yield t.label;\r\n    yield* inorder(t.right);\r\n  }\r\n}\r\n\r\n\/\/ \u4e0b\u9762\u751f\u6210\u4e8c\u53c9\u6811\r\nfunction make(array) {\r\n  \/\/ \u5224\u65ad\u662f\u5426\u4e3a\u53f6\u8282\u70b9\r\n  if (array.length == 1) return new Tree(null, array[0], null);\r\n  return new Tree(make(array[0]), array[1], make(array[2]));\r\n}\r\nlet tree = make([[['a'], 'b', ['c']], 'd', [['e'], 'f', ['g']]]);\r\n\r\n\/\/ \u904d\u5386\u4e8c\u53c9\u6811\r\nvar result = [];\r\nfor (let node of inorder(tree)) {\r\n  result.push(node);\r\n}\r\n\r\nresult\r\n\/\/ ['a', 'b', 'c', 'd', 'e', 'f', 'g']<\/pre>\n<h2 id=\"\u4f5c\u4e3a\u5bf9\u8c61\u5c5e\u6027\u7684generator\u51fd\u6570\">\u4f5c\u4e3a\u5bf9\u8c61\u5c5e\u6027\u7684Generator\u51fd\u6570<\/h2>\n<p>\u5982\u679c\u4e00\u4e2a\u5bf9\u8c61\u7684\u5c5e\u6027\u662fGenerator\u51fd\u6570\uff0c\u53ef\u4ee5\u7b80\u5199\u6210\u4e0b\u9762\u7684\u5f62\u5f0f\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">let obj = {\r\n  * myGeneratorMethod() {\r\n    \u00b7\u00b7\u00b7\r\n  }\r\n};<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c<code>myGeneratorMethod<\/code>\u5c5e\u6027\u524d\u9762\u6709\u4e00\u4e2a\u661f\u53f7\uff0c\u8868\u793a\u8fd9\u4e2a\u5c5e\u6027\u662f\u4e00\u4e2aGenerator\u51fd\u6570\u3002<\/p>\n<p>\u5b83\u7684\u5b8c\u6574\u5f62\u5f0f\u5982\u4e0b\uff0c\u4e0e\u4e0a\u9762\u7684\u5199\u6cd5\u662f\u7b49\u4ef7\u7684\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">let obj = {\r\n  myGeneratorMethod: function* () {\r\n    \/\/ \u00b7\u00b7\u00b7\r\n  }\r\n};<\/pre>\n<h2 id=\"generator\u51fd\u6570\u7684this\">Generator\u51fd\u6570\u7684<code>this<\/code><\/h2>\n<p>Generator\u51fd\u6570\u603b\u662f\u8fd4\u56de\u4e00\u4e2a\u904d\u5386\u5668\uff0cES6\u89c4\u5b9a\u8fd9\u4e2a\u904d\u5386\u5668\u662fGenerator\u51fd\u6570\u7684\u5b9e\u4f8b\uff0c\u4e5f\u7ee7\u627f\u4e86Generator\u51fd\u6570\u7684<code>prototype<\/code>\u5bf9\u8c61\u4e0a\u7684\u65b9\u6cd5\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* g() {}\r\ng.prototype.hello = function () {\r\n  return 'hi!';\r\n};\r\nlet obj = g();\r\nobj instanceof g \/\/ true\r\nobj.hello() \/\/ 'hi!'<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u8868\u660e\uff0cGenerator\u51fd\u6570<code>g<\/code>\u8fd4\u56de\u7684\u904d\u5386\u5668<code>obj<\/code>\uff0c\u662f<code>g<\/code>\u7684\u5b9e\u4f8b\uff0c\u800c\u4e14\u7ee7\u627f\u4e86<code>g.prototype<\/code>\u3002\u4f46\u662f\uff0c\u5982\u679c\u628a<code>g<\/code>\u5f53\u4f5c\u666e\u901a\u7684\u6784\u9020\u51fd\u6570\uff0c\u5e76\u4e0d\u4f1a\u751f\u6548\uff0c\u56e0\u4e3a<code>g<\/code>\u8fd4\u56de\u7684\u603b\u662f\u904d\u5386\u5668\u5bf9\u8c61\uff0c\u800c\u4e0d\u662f<code>this<\/code>\u5bf9\u8c61\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* g() {\r\n  this.a = 11;\r\n}\r\nlet obj = g();\r\nobj.a \/\/ undefined<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0cGenerator\u51fd\u6570<code>g<\/code>\u5728<code>this<\/code>\u5bf9\u8c61\u4e0a\u9762\u6dfb\u52a0\u4e86\u4e00\u4e2a\u5c5e\u6027<code>a<\/code>\uff0c\u4f46\u662f<code>obj<\/code>\u5bf9\u8c61\u62ff\u4e0d\u5230\u8fd9\u4e2a\u5c5e\u6027\u3002<\/p>\n<p>Generator\u51fd\u6570\u4e5f\u4e0d\u80fd\u8ddf<code>new<\/code>\u547d\u4ee4\u4e00\u8d77\u7528\uff0c\u4f1a\u62a5\u9519\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* F() {\r\n  yield this.x = 2;\r\n  yield this.y = 3;\r\n}\r\nnew F()\r\n\/\/ TypeError: F is not a constructor<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c<code>new<\/code>\u547d\u4ee4\u8ddf\u6784\u9020\u51fd\u6570<code>F<\/code>\u4e00\u8d77\u4f7f\u7528\uff0c\u7ed3\u679c\u62a5\u9519\uff0c\u56e0\u4e3a<code>F<\/code>\u4e0d\u662f\u6784\u9020\u51fd\u6570\u3002<\/p>\n<p>\u90a3\u4e48\uff0c\u6709\u6ca1\u6709\u529e\u6cd5\u8ba9Generator\u51fd\u6570\u8fd4\u56de\u4e00\u4e2a\u6b63\u5e38\u7684\u5bf9\u8c61\u5b9e\u4f8b\uff0c\u65e2\u53ef\u4ee5\u7528<code>next<\/code>\u65b9\u6cd5\uff0c\u53c8\u53ef\u4ee5\u83b7\u5f97\u6b63\u5e38\u7684<code>this<\/code>\uff1f<\/p>\n<p>\u4e0b\u9762\u662f\u4e00\u4e2a\u53d8\u901a\u65b9\u6cd5\u3002\u9996\u5148\uff0c\u751f\u6210\u4e00\u4e2a\u7a7a\u5bf9\u8c61\uff0c\u4f7f\u7528<code>call<\/code>\u65b9\u6cd5\u7ed1\u5b9aGenerator\u51fd\u6570\u5185\u90e8\u7684<code>this<\/code>\u3002\u8fd9\u6837\uff0c\u6784\u9020\u51fd\u6570\u8c03\u7528\u4ee5\u540e\uff0c\u8fd9\u4e2a\u7a7a\u5bf9\u8c61\u5c31\u662fGenerator\u51fd\u6570\u7684\u5b9e\u4f8b\u5bf9\u8c61\u4e86\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* F() {\r\n  this.a = 1;\r\n  yield this.b = 2;\r\n  yield this.c = 3;\r\n}\r\nvar obj = {};\r\nvar f = F.call(obj);\r\nf.next();  \/\/ Object {value: 2, done: false}\r\nf.next();  \/\/ Object {value: 3, done: false}\r\nf.next();  \/\/ Object {value: undefined, done: true}\r\nobj.a \/\/ 1\r\nobj.b \/\/ 2\r\nobj.c \/\/ 3<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c\u9996\u5148\u662f<code>F<\/code>\u5185\u90e8\u7684<code>this<\/code>\u5bf9\u8c61\u7ed1\u5b9a<code>obj<\/code>\u5bf9\u8c61\uff0c\u7136\u540e\u8c03\u7528\u5b83\uff0c\u8fd4\u56de\u4e00\u4e2aIterator\u5bf9\u8c61\u3002\u8fd9\u4e2a\u5bf9\u8c61\u6267\u884c\u4e09\u6b21<code>next<\/code>\u65b9\u6cd5\uff08\u56e0\u4e3a<code>F<\/code>\u5185\u90e8\u6709\u4e24\u4e2a<code>yield<\/code>\u8bed\u53e5\uff09\uff0c\u5b8c\u6210F\u5185\u90e8\u6240\u6709\u4ee3\u7801\u7684\u8fd0\u884c\u3002\u8fd9\u65f6\uff0c\u6240\u6709\u5185\u90e8\u5c5e\u6027\u90fd\u7ed1\u5b9a\u5728<code>obj<\/code>\u5bf9\u8c61\u4e0a\u4e86\uff0c\u56e0\u6b64<code>obj<\/code>\u5bf9\u8c61\u4e5f\u5c31\u6210\u4e86<code>F<\/code>\u7684\u5b9e\u4f8b\u3002<\/p>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c\u6267\u884c\u7684\u662f\u904d\u5386\u5668\u5bf9\u8c61<code>f<\/code>\uff0c\u4f46\u662f\u751f\u6210\u7684\u5bf9\u8c61\u5b9e\u4f8b\u662f<code>obj<\/code>\uff0c\u6709\u6ca1\u6709\u529e\u6cd5\u5c06\u8fd9\u4e24\u4e2a\u5bf9\u8c61\u7edf\u4e00\u5462\uff1f<\/p>\n<p>\u4e00\u4e2a\u529e\u6cd5\u5c31\u662f\u5c06<code>obj<\/code>\u6362\u6210<code>F.prototype<\/code>\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* F() {\r\n  this.a = 1;\r\n  yield this.b = 2;\r\n  yield this.c = 3;\r\n}\r\nvar f = F.call(F.prototype);\r\n\r\nf.next();  \/\/ Object {value: 2, done: false}\r\nf.next();  \/\/ Object {value: 3, done: false}\r\nf.next();  \/\/ Object {value: undefined, done: true}\r\n\r\nf.a \/\/ 1\r\nf.b \/\/ 2\r\nf.c \/\/ 3<\/pre>\n<p>\u518d\u5c06<code>F<\/code>\u6539\u6210\u6784\u9020\u51fd\u6570\uff0c\u5c31\u53ef\u4ee5\u5bf9\u5b83\u6267\u884c<code>new<\/code>\u547d\u4ee4\u4e86\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* gen() {\r\n  this.a = 1;\r\n  yield this.b = 2;\r\n  yield this.c = 3;\r\n}\r\n\r\nfunction F() {\r\n  return gen.call(gen.prototype);\r\n}\r\n\r\nvar f = new F();\r\n\r\nf.next();  \/\/ Object {value: 2, done: false}\r\nf.next();  \/\/ Object {value: 3, done: false}\r\nf.next();  \/\/ Object {value: undefined, done: true}\r\n\r\nf.a \/\/ 1\r\nf.b \/\/ 2\r\nf.c \/\/ 3<\/pre>\n<h2 id=\"\u542b\u4e49\">\u542b\u4e49<\/h2>\n<h3 id=\"generator\u4e0e\u72b6\u6001\u673a\"><a name=\"t12\"><\/a>Generator\u4e0e\u72b6\u6001\u673a<\/h3>\n<p>Generator\u662f\u5b9e\u73b0\u72b6\u6001\u673a\u7684\u6700\u4f73\u7ed3\u6784\u3002\u6bd4\u5982\uff0c\u4e0b\u9762\u7684clock\u51fd\u6570\u5c31\u662f\u4e00\u4e2a\u72b6\u6001\u673a\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">var ticking = true;\r\nvar clock = function() {\r\n  if (ticking)\r\n    console.log('Tick!');\r\n  else\r\n    console.log('Tock!');\r\n  ticking = !ticking;\r\n}<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u7684clock\u51fd\u6570\u4e00\u5171\u6709\u4e24\u79cd\u72b6\u6001\uff08Tick\u548cTock\uff09\uff0c\u6bcf\u8fd0\u884c\u4e00\u6b21\uff0c\u5c31\u6539\u53d8\u4e00\u6b21\u72b6\u6001\u3002\u8fd9\u4e2a\u51fd\u6570\u5982\u679c\u7528Generator\u5b9e\u73b0\uff0c\u5c31\u662f\u4e0b\u9762\u8fd9\u6837\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">var clock = function*() {\r\n  while (true) {\r\n    console.log('Tick!');\r\n    yield;\r\n    console.log('Tock!');\r\n    yield;\r\n  }\r\n};<\/pre>\n<p>\u4e0a\u9762\u7684Generator\u5b9e\u73b0\u4e0eES5\u5b9e\u73b0\u5bf9\u6bd4\uff0c\u53ef\u4ee5\u770b\u5230\u5c11\u4e86\u7528\u6765\u4fdd\u5b58\u72b6\u6001\u7684\u5916\u90e8\u53d8\u91cf<code>ticking<\/code>\uff0c\u8fd9\u6837\u5c31\u66f4\u7b80\u6d01\uff0c\u66f4\u5b89\u5168\uff08\u72b6\u6001\u4e0d\u4f1a\u88ab\u975e\u6cd5\u7be1\u6539\uff09\u3001\u66f4\u7b26\u5408\u51fd\u6570\u5f0f\u7f16\u7a0b\u7684\u601d\u60f3\uff0c\u5728\u5199\u6cd5\u4e0a\u4e5f\u66f4\u4f18\u96c5\u3002Generator\u4e4b\u6240\u4ee5\u53ef\u4ee5\u4e0d\u7528\u5916\u90e8\u53d8\u91cf\u4fdd\u5b58\u72b6\u6001\uff0c\u662f\u56e0\u4e3a\u5b83\u672c\u8eab\u5c31\u5305\u542b\u4e86\u4e00\u4e2a\u72b6\u6001\u4fe1\u606f\uff0c\u5373\u76ee\u524d\u662f\u5426\u5904\u4e8e\u6682\u505c\u6001\u3002<\/p>\n<h3 id=\"generator\u4e0e\u534f\u7a0b\"><a name=\"t13\"><\/a>Generator\u4e0e\u534f\u7a0b<\/h3>\n<p>\u534f\u7a0b\uff08coroutine\uff09\u662f\u4e00\u79cd\u7a0b\u5e8f\u8fd0\u884c\u7684\u65b9\u5f0f\uff0c\u53ef\u4ee5\u7406\u89e3\u6210\u201c\u534f\u4f5c\u7684\u7ebf\u7a0b\u201d\u6216\u201c\u534f\u4f5c\u7684\u51fd\u6570\u201d\u3002\u534f\u7a0b\u65e2\u53ef\u4ee5\u7528\u5355\u7ebf\u7a0b\u5b9e\u73b0\uff0c\u4e5f\u53ef\u4ee5\u7528\u591a\u7ebf\u7a0b\u5b9e\u73b0\u3002\u524d\u8005\u662f\u4e00\u79cd\u7279\u6b8a\u7684\u5b50\u4f8b\u7a0b\uff0c\u540e\u8005\u662f\u4e00\u79cd\u7279\u6b8a\u7684\u7ebf\u7a0b\u3002<\/p>\n<p><strong>\uff081\uff09\u534f\u7a0b\u4e0e\u5b50\u4f8b\u7a0b\u7684\u5dee\u5f02<\/strong><\/p>\n<p>\u4f20\u7edf\u7684\u201c\u5b50\u4f8b\u7a0b\u201d\uff08subroutine\uff09\u91c7\u7528\u5806\u6808\u5f0f\u201c\u540e\u8fdb\u5148\u51fa\u201d\u7684\u6267\u884c\u65b9\u5f0f\uff0c\u53ea\u6709\u5f53\u8c03\u7528\u7684\u5b50\u51fd\u6570\u5b8c\u5168\u6267\u884c\u5b8c\u6bd5\uff0c\u624d\u4f1a\u7ed3\u675f\u6267\u884c\u7236\u51fd\u6570\u3002\u534f\u7a0b\u4e0e\u5176\u4e0d\u540c\uff0c\u591a\u4e2a\u7ebf\u7a0b\uff08\u5355\u7ebf\u7a0b\u60c5\u51b5\u4e0b\uff0c\u5373\u591a\u4e2a\u51fd\u6570\uff09\u53ef\u4ee5\u5e76\u884c\u6267\u884c\uff0c\u4f46\u662f\u53ea\u6709\u4e00\u4e2a\u7ebf\u7a0b\uff08\u6216\u51fd\u6570\uff09\u5904\u4e8e\u6b63\u5728\u8fd0\u884c\u7684\u72b6\u6001\uff0c\u5176\u4ed6\u7ebf\u7a0b\uff08\u6216\u51fd\u6570\uff09\u90fd\u5904\u4e8e\u6682\u505c\u6001\uff08suspended\uff09\uff0c\u7ebf\u7a0b\uff08\u6216\u51fd\u6570\uff09\u4e4b\u95f4\u53ef\u4ee5\u4ea4\u6362\u6267\u884c\u6743\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u4e00\u4e2a\u7ebf\u7a0b\uff08\u6216\u51fd\u6570\uff09\u6267\u884c\u5230\u4e00\u534a\uff0c\u53ef\u4ee5\u6682\u505c\u6267\u884c\uff0c\u5c06\u6267\u884c\u6743\u4ea4\u7ed9\u53e6\u4e00\u4e2a\u7ebf\u7a0b\uff08\u6216\u51fd\u6570\uff09\uff0c\u7b49\u5230\u7a0d\u540e\u6536\u56de\u6267\u884c\u6743\u7684\u65f6\u5019\uff0c\u518d\u6062\u590d\u6267\u884c\u3002\u8fd9\u79cd\u53ef\u4ee5\u5e76\u884c\u6267\u884c\u3001\u4ea4\u6362\u6267\u884c\u6743\u7684\u7ebf\u7a0b\uff08\u6216\u51fd\u6570\uff09\uff0c\u5c31\u79f0\u4e3a\u534f\u7a0b\u3002<\/p>\n<p>\u4ece\u5b9e\u73b0\u4e0a\u770b\uff0c\u5728\u5185\u5b58\u4e2d\uff0c\u5b50\u4f8b\u7a0b\u53ea\u4f7f\u7528\u4e00\u4e2a\u6808\uff08stack\uff09\uff0c\u800c\u534f\u7a0b\u662f\u540c\u65f6\u5b58\u5728\u591a\u4e2a\u6808\uff0c\u4f46\u53ea\u6709\u4e00\u4e2a\u6808\u662f\u5728\u8fd0\u884c\u72b6\u6001\uff0c\u4e5f\u5c31\u662f\u8bf4\uff0c\u534f\u7a0b\u662f\u4ee5\u591a\u5360\u7528\u5185\u5b58\u4e3a\u4ee3\u4ef7\uff0c\u5b9e\u73b0\u591a\u4efb\u52a1\u7684\u5e76\u884c\u3002<\/p>\n<p><strong>\uff082\uff09\u534f\u7a0b\u4e0e\u666e\u901a\u7ebf\u7a0b\u7684\u5dee\u5f02<\/strong><\/p>\n<p>\u4e0d\u96be\u770b\u51fa\uff0c\u534f\u7a0b\u9002\u5408\u7528\u4e8e\u591a\u4efb\u52a1\u8fd0\u884c\u7684\u73af\u5883\u3002\u5728\u8fd9\u4e2a\u610f\u4e49\u4e0a\uff0c\u5b83\u4e0e\u666e\u901a\u7684\u7ebf\u7a0b\u5f88\u76f8\u4f3c\uff0c\u90fd\u6709\u81ea\u5df1\u7684\u6267\u884c\u4e0a\u4e0b\u6587\u3001\u53ef\u4ee5\u5206\u4eab\u5168\u5c40\u53d8\u91cf\u3002\u5b83\u4eec\u7684\u4e0d\u540c\u4e4b\u5904\u5728\u4e8e\uff0c\u540c\u4e00\u65f6\u95f4\u53ef\u4ee5\u6709\u591a\u4e2a\u7ebf\u7a0b\u5904\u4e8e\u8fd0\u884c\u72b6\u6001\uff0c\u4f46\u662f\u8fd0\u884c\u7684\u534f\u7a0b\u53ea\u80fd\u6709\u4e00\u4e2a\uff0c\u5176\u4ed6\u534f\u7a0b\u90fd\u5904\u4e8e\u6682\u505c\u72b6\u6001\u3002\u6b64\u5916\uff0c\u666e\u901a\u7684\u7ebf\u7a0b\u662f\u62a2\u5148\u5f0f\u7684\uff0c\u5230\u5e95\u54ea\u4e2a\u7ebf\u7a0b\u4f18\u5148\u5f97\u5230\u8d44\u6e90\uff0c\u5fc5\u987b\u7531\u8fd0\u884c\u73af\u5883\u51b3\u5b9a\uff0c\u4f46\u662f\u534f\u7a0b\u662f\u5408\u4f5c\u5f0f\u7684\uff0c\u6267\u884c\u6743\u7531\u534f\u7a0b\u81ea\u5df1\u5206\u914d\u3002<\/p>\n<p>\u7531\u4e8eECMAScript\u662f\u5355\u7ebf\u7a0b\u8bed\u8a00\uff0c\u53ea\u80fd\u4fdd\u6301\u4e00\u4e2a\u8c03\u7528\u6808\u3002\u5f15\u5165\u534f\u7a0b\u4ee5\u540e\uff0c\u6bcf\u4e2a\u4efb\u52a1\u53ef\u4ee5\u4fdd\u6301\u81ea\u5df1\u7684\u8c03\u7528\u6808\u3002\u8fd9\u6837\u505a\u7684\u6700\u5927\u597d\u5904\uff0c\u5c31\u662f\u629b\u51fa\u9519\u8bef\u7684\u65f6\u5019\uff0c\u53ef\u4ee5\u627e\u5230\u539f\u59cb\u7684\u8c03\u7528\u6808\u3002\u4e0d\u81f3\u4e8e\u50cf\u5f02\u6b65\u64cd\u4f5c\u7684\u56de\u8c03\u51fd\u6570\u90a3\u6837\uff0c\u4e00\u65e6\u51fa\u9519\uff0c\u539f\u59cb\u7684\u8c03\u7528\u6808\u65e9\u5c31\u7ed3\u675f\u3002<\/p>\n<p>Generator\u51fd\u6570\u662fECMAScript 6\u5bf9\u534f\u7a0b\u7684\u5b9e\u73b0\uff0c\u4f46\u5c5e\u4e8e\u4e0d\u5b8c\u5168\u5b9e\u73b0\u3002Generator\u51fd\u6570\u88ab\u79f0\u4e3a\u201c\u534a\u534f\u7a0b\u201d\uff08semi-coroutine\uff09\uff0c\u610f\u601d\u662f\u53ea\u6709Generator\u51fd\u6570\u7684\u8c03\u7528\u8005\uff0c\u624d\u80fd\u5c06\u7a0b\u5e8f\u7684\u6267\u884c\u6743\u8fd8\u7ed9Generator\u51fd\u6570\u3002\u5982\u679c\u662f\u5b8c\u5168\u6267\u884c\u7684\u534f\u7a0b\uff0c\u4efb\u4f55\u51fd\u6570\u90fd\u53ef\u4ee5\u8ba9\u6682\u505c\u7684\u534f\u7a0b\u7ee7\u7eed\u6267\u884c\u3002<\/p>\n<p>\u5982\u679c\u5c06Generator\u51fd\u6570\u5f53\u4f5c\u534f\u7a0b\uff0c\u5b8c\u5168\u53ef\u4ee5\u5c06\u591a\u4e2a\u9700\u8981\u4e92\u76f8\u534f\u4f5c\u7684\u4efb\u52a1\u5199\u6210Generator\u51fd\u6570\uff0c\u5b83\u4eec\u4e4b\u95f4\u4f7f\u7528yield\u8bed\u53e5\u4ea4\u6362\u63a7\u5236\u6743\u3002<\/p>\n<h2 id=\"\u5e94\u7528\"><a name=\"t14\"><\/a>\u5e94\u7528<\/h2>\n<p>Generator\u53ef\u4ee5\u6682\u505c\u51fd\u6570\u6267\u884c\uff0c\u8fd4\u56de\u4efb\u610f\u8868\u8fbe\u5f0f\u7684\u503c\u3002\u8fd9\u79cd\u7279\u70b9\u4f7f\u5f97Generator\u6709\u591a\u79cd\u5e94\u7528\u573a\u666f\u3002<\/p>\n<h3 id=\"1\u5f02\u6b65\u64cd\u4f5c\u7684\u540c\u6b65\u5316\u8868\u8fbe\"><a name=\"t15\"><\/a>\uff081\uff09\u5f02\u6b65\u64cd\u4f5c\u7684\u540c\u6b65\u5316\u8868\u8fbe<\/h3>\n<p>Generator\u51fd\u6570\u7684\u6682\u505c\u6267\u884c\u7684\u6548\u679c\uff0c\u610f\u5473\u7740\u53ef\u4ee5\u628a\u5f02\u6b65\u64cd\u4f5c\u5199\u5728yield\u8bed\u53e5\u91cc\u9762\uff0c\u7b49\u5230\u8c03\u7528next\u65b9\u6cd5\u65f6\u518d\u5f80\u540e\u6267\u884c\u3002\u8fd9\u5b9e\u9645\u4e0a\u7b49\u540c\u4e8e\u4e0d\u9700\u8981\u5199\u56de\u8c03\u51fd\u6570\u4e86\uff0c\u56e0\u4e3a\u5f02\u6b65\u64cd\u4f5c\u7684\u540e\u7eed\u64cd\u4f5c\u53ef\u4ee5\u653e\u5728yield\u8bed\u53e5\u4e0b\u9762\uff0c\u53cd\u6b63\u8981\u7b49\u5230\u8c03\u7528next\u65b9\u6cd5\u65f6\u518d\u6267\u884c\u3002\u6240\u4ee5\uff0cGenerator\u51fd\u6570\u7684\u4e00\u4e2a\u91cd\u8981\u5b9e\u9645\u610f\u4e49\u5c31\u662f\u7528\u6765\u5904\u7406\u5f02\u6b65\u64cd\u4f5c\uff0c\u6539\u5199\u56de\u8c03\u51fd\u6570\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* loadUI() {\r\n  showLoadingScreen();\r\n  yield loadUIDataAsynchronously();\r\n  hideLoadingScreen();\r\n}\r\nvar loader = loadUI();\r\n\/\/ \u52a0\u8f7dUI\r\nloader.next()\r\n\r\n\/\/ \u5378\u8f7dUI\r\nloader.next()<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u8868\u793a\uff0c\u7b2c\u4e00\u6b21\u8c03\u7528loadUI\u51fd\u6570\u65f6\uff0c\u8be5\u51fd\u6570\u4e0d\u4f1a\u6267\u884c\uff0c\u4ec5\u8fd4\u56de\u4e00\u4e2a\u904d\u5386\u5668\u3002\u4e0b\u4e00\u6b21\u5bf9\u8be5\u904d\u5386\u5668\u8c03\u7528next\u65b9\u6cd5\uff0c\u5219\u4f1a\u663e\u793aLoading\u754c\u9762\uff0c\u5e76\u4e14\u5f02\u6b65\u52a0\u8f7d\u6570\u636e\u3002\u7b49\u5230\u6570\u636e\u52a0\u8f7d\u5b8c\u6210\uff0c\u518d\u4e00\u6b21\u4f7f\u7528next\u65b9\u6cd5\uff0c\u5219\u4f1a\u9690\u85cfLoading\u754c\u9762\u3002\u53ef\u4ee5\u770b\u5230\uff0c\u8fd9\u79cd\u5199\u6cd5\u7684\u597d\u5904\u662f\u6240\u6709Loading\u754c\u9762\u7684\u903b\u8f91\uff0c\u90fd\u88ab\u5c01\u88c5\u5728\u4e00\u4e2a\u51fd\u6570\uff0c\u6309\u90e8\u5c31\u73ed\u975e\u5e38\u6e05\u6670\u3002<\/p>\n<p>Ajax\u662f\u5178\u578b\u7684\u5f02\u6b65\u64cd\u4f5c\uff0c\u901a\u8fc7Generator\u51fd\u6570\u90e8\u7f72Ajax\u64cd\u4f5c\uff0c\u53ef\u4ee5\u7528\u540c\u6b65\u7684\u65b9\u5f0f\u8868\u8fbe\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* main() {\r\n  var result = yield request(\"http:\/\/some.url\");\r\n  var resp = JSON.parse(result);\r\n    console.log(resp.value);\r\n}\r\n\r\nfunction request(url) {\r\n  makeAjaxCall(url, function(response){\r\n    it.next(response);\r\n  });\r\n}\r\n\r\nvar it = main();\r\nit.next();<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u7684main\u51fd\u6570\uff0c\u5c31\u662f\u901a\u8fc7Ajax\u64cd\u4f5c\u83b7\u53d6\u6570\u636e\u3002\u53ef\u4ee5\u770b\u5230\uff0c\u9664\u4e86\u591a\u4e86\u4e00\u4e2ayield\uff0c\u5b83\u51e0\u4e4e\u4e0e\u540c\u6b65\u64cd\u4f5c\u7684\u5199\u6cd5\u5b8c\u5168\u4e00\u6837\u3002\u6ce8\u610f\uff0cmakeAjaxCall\u51fd\u6570\u4e2d\u7684next\u65b9\u6cd5\uff0c\u5fc5\u987b\u52a0\u4e0aresponse\u53c2\u6570\uff0c\u56e0\u4e3ayield\u8bed\u53e5\u6784\u6210\u7684\u8868\u8fbe\u5f0f\uff0c\u672c\u8eab\u662f\u6ca1\u6709\u503c\u7684\uff0c\u603b\u662f\u7b49\u4e8eundefined\u3002<\/p>\n<p>\u4e0b\u9762\u662f\u53e6\u4e00\u4e2a\u4f8b\u5b50\uff0c\u901a\u8fc7Generator\u51fd\u6570\u9010\u884c\u8bfb\u53d6\u6587\u672c\u6587\u4ef6\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* numbers() {\r\n  let file = new FileReader(\"numbers.txt\");\r\n  try {\r\n    while(!file.eof) {\r\n      yield parseInt(file.readLine(), 10);\r\n    }\r\n  } finally {\r\n    file.close();\r\n  }\r\n}<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u6253\u5f00\u6587\u672c\u6587\u4ef6\uff0c\u4f7f\u7528yield\u8bed\u53e5\u53ef\u4ee5\u624b\u52a8\u9010\u884c\u8bfb\u53d6\u6587\u4ef6\u3002<\/p>\n<h3 id=\"2\u63a7\u5236\u6d41\u7ba1\u7406\"><a name=\"t16\"><\/a>\uff082\uff09\u63a7\u5236\u6d41\u7ba1\u7406<\/h3>\n<p>\u5982\u679c\u6709\u4e00\u4e2a\u591a\u6b65\u64cd\u4f5c\u975e\u5e38\u8017\u65f6\uff0c\u91c7\u7528\u56de\u8c03\u51fd\u6570\uff0c\u53ef\u80fd\u4f1a\u5199\u6210\u4e0b\u9762\u8fd9\u6837\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">step1(function (value1) {\r\n  step2(value1, function(value2) {\r\n    step3(value2, function(value3) {\r\n      step4(value3, function(value4) {\r\n        \/\/ Do something with value4\r\n      });\r\n    });\r\n  });\r\n});<\/pre>\n<p>\u91c7\u7528Promise\u6539\u5199\u4e0a\u9762\u7684\u4ee3\u7801\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">Promise.resolve(step1)\r\n  .then(step2)\r\n  .then(step3)\r\n  .then(step4)\r\n  .then(function (value4) {\r\n    \/\/ Do something with value4\r\n  }, function (error) {\r\n    \/\/ Handle any error from step1 through step4\r\n  })\r\n  .done();<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u5df2\u7ecf\u628a\u56de\u8c03\u51fd\u6570\uff0c\u6539\u6210\u4e86\u76f4\u7ebf\u6267\u884c\u7684\u5f62\u5f0f\uff0c\u4f46\u662f\u52a0\u5165\u4e86\u5927\u91cfPromise\u7684\u8bed\u6cd5\u3002Generator\u51fd\u6570\u53ef\u4ee5\u8fdb\u4e00\u6b65\u6539\u5584\u4ee3\u7801\u8fd0\u884c\u6d41\u7a0b\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* longRunningTask(value1) {\r\n  try {\r\n    var value2 = yield step1(value1);\r\n    var value3 = yield step2(value2);\r\n    var value4 = yield step3(value3);\r\n    var value5 = yield step4(value4);\r\n    \/\/ Do something with value4\r\n  } catch (e) {\r\n    \/\/ Handle any error from step1 through step4\r\n  }\r\n}<\/pre>\n<p>\u7136\u540e\uff0c\u4f7f\u7528\u4e00\u4e2a\u51fd\u6570\uff0c\u6309\u6b21\u5e8f\u81ea\u52a8\u6267\u884c\u6240\u6709\u6b65\u9aa4\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">scheduler(longRunningTask(initialValue));\r\n\r\nfunction scheduler(task) {\r\n  var taskObj = task.next(task.value);\r\n  \/\/ \u5982\u679cGenerator\u51fd\u6570\u672a\u7ed3\u675f\uff0c\u5c31\u7ee7\u7eed\u8c03\u7528\r\n  if (!taskObj.done) {\r\n    task.value = taskObj.value\r\n    scheduler(task);\r\n  }\r\n}<\/pre>\n<p>\u6ce8\u610f\uff0c\u4e0a\u9762\u8fd9\u79cd\u505a\u6cd5\uff0c\u53ea\u9002\u5408\u540c\u6b65\u64cd\u4f5c\uff0c\u5373\u6240\u6709\u7684<code>task<\/code>\u90fd\u5fc5\u987b\u662f\u540c\u6b65\u7684\uff0c\u4e0d\u80fd\u6709\u5f02\u6b65\u64cd\u4f5c\u3002\u56e0\u4e3a\u8fd9\u91cc\u7684\u4ee3\u7801\u4e00\u5f97\u5230\u8fd4\u56de\u503c\uff0c\u5c31\u7ee7\u7eed\u5f80\u4e0b\u6267\u884c\uff0c\u6ca1\u6709\u5224\u65ad\u5f02\u6b65\u64cd\u4f5c\u4f55\u65f6\u5b8c\u6210\u3002\u5982\u679c\u8981\u63a7\u5236\u5f02\u6b65\u7684\u64cd\u4f5c\u6d41\u7a0b\uff0c\u8be6\u89c1\u540e\u9762\u7684\u300a\u5f02\u6b65\u64cd\u4f5c\u300b\u4e00\u7ae0\u3002<\/p>\n<p>\u4e0b\u9762\uff0c\u5229\u7528<code>for...of<\/code>\u5faa\u73af\u4f1a\u81ea\u52a8\u4f9d\u6b21\u6267\u884c<code>yield<\/code>\u547d\u4ee4\u7684\u7279\u6027\uff0c\u63d0\u4f9b\u4e00\u79cd\u66f4\u4e00\u822c\u7684\u63a7\u5236\u6d41\u7ba1\u7406\u7684\u65b9\u6cd5\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">let steps = [step1Func, step2Func, step3Func];\r\n\r\nfunction *iterateSteps(steps){\r\n  for (var i=0; i&lt; steps.length; i++){\r\n    var step = steps[i];\r\n    yield step();\r\n  }\r\n}<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c\u6570\u7ec4<code>steps<\/code>\u5c01\u88c5\u4e86\u4e00\u4e2a\u4efb\u52a1\u7684\u591a\u4e2a\u6b65\u9aa4\uff0cGenerator\u51fd\u6570<code>iterateSteps<\/code>\u5219\u662f\u4f9d\u6b21\u4e3a\u8fd9\u4e9b\u6b65\u9aa4\u52a0\u4e0a<code>yield<\/code>\u547d\u4ee4\u3002<\/p>\n<p>\u5c06\u4efb\u52a1\u5206\u89e3\u6210\u6b65\u9aa4\u4e4b\u540e\uff0c\u8fd8\u53ef\u4ee5\u5c06\u9879\u76ee\u5206\u89e3\u6210\u591a\u4e2a\u4f9d\u6b21\u6267\u884c\u7684\u4efb\u52a1\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">let jobs = [job1, job2, job3];\r\n\r\nfunction *iterateJobs(jobs){\r\n  for (var i=0; i&lt; jobs.length; i++){\r\n    var job = jobs[i];\r\n    yield *iterateSteps(job.steps);\r\n  }\r\n}<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u4e2d\uff0c\u6570\u7ec4<code>jobs<\/code>\u5c01\u88c5\u4e86\u4e00\u4e2a\u9879\u76ee\u7684\u591a\u4e2a\u4efb\u52a1\uff0cGenerator\u51fd\u6570<code>iterateJobs<\/code>\u5219\u662f\u4f9d\u6b21\u4e3a\u8fd9\u4e9b\u4efb\u52a1\u52a0\u4e0a<code>yield *<\/code>\u547d\u4ee4\u3002<\/p>\n<p>\u6700\u540e\uff0c\u5c31\u53ef\u4ee5\u7528<code>for...of<\/code>\u5faa\u73af\u4e00\u6b21\u6027\u4f9d\u6b21\u6267\u884c\u6240\u6709\u4efb\u52a1\u7684\u6240\u6709\u6b65\u9aa4\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">for (var step of iterateJobs(jobs)){\r\n  console.log(step.id);\r\n}<\/pre>\n<p>\u518d\u6b21\u63d0\u9192\uff0c\u4e0a\u9762\u7684\u505a\u6cd5\u53ea\u80fd\u7528\u4e8e\u6240\u6709\u6b65\u9aa4\u90fd\u662f\u540c\u6b65\u64cd\u4f5c\u7684\u60c5\u51b5\uff0c\u4e0d\u80fd\u6709\u5f02\u6b65\u64cd\u4f5c\u7684\u6b65\u9aa4\u3002<\/p>\n<p><code>for...of<\/code>\u7684\u672c\u8d28\u662f\u4e00\u4e2a<code>while<\/code>\u5faa\u73af\uff0c\u6240\u4ee5\u4e0a\u9762\u7684\u4ee3\u7801\u5b9e\u8d28\u4e0a\u6267\u884c\u7684\u662f\u4e0b\u9762\u7684\u903b\u8f91\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">var it = iterateJobs(jobs);\r\nvar res = it.next();\r\n\r\nwhile (!res.done){\r\n  var result = res.value;\r\n  \/\/ ...\r\n  res = it.next();\r\n}<\/pre>\n<h3 id=\"3\u90e8\u7f72iterator\u63a5\u53e3\">\uff083\uff09\u90e8\u7f72Iterator\u63a5\u53e3<\/h3>\n<p>\u5229\u7528Generator\u51fd\u6570\uff0c\u53ef\u4ee5\u5728\u4efb\u610f\u5bf9\u8c61\u4e0a\u90e8\u7f72Iterator\u63a5\u53e3\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* iterEntries(obj) {\r\n  let keys = Object.keys(obj);\r\n  for (let i=0; i &lt; keys.length; i++) {\r\n    let key = keys[i];\r\n    yield [key, obj[key]];\r\n  }\r\n}\r\n\r\nlet myObj = { foo: 3, bar: 7 };\r\n\r\nfor (let [key, value] of iterEntries(myObj)) {\r\n  console.log(key, value);\r\n}\r\n\r\n\/\/ foo 3\r\n\/\/ bar 7<\/pre>\n<p>\u4e0a\u8ff0\u4ee3\u7801\u4e2d\uff0c<code>myObj<\/code>\u662f\u4e00\u4e2a\u666e\u901a\u5bf9\u8c61\uff0c\u901a\u8fc7<code>iterEntries<\/code>\u51fd\u6570\uff0c\u5c31\u6709\u4e86Iterator\u63a5\u53e3\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u53ef\u4ee5\u5728\u4efb\u610f\u5bf9\u8c61\u4e0a\u90e8\u7f72<code>next<\/code>\u65b9\u6cd5\u3002<\/p>\n<p>\u4e0b\u9762\u662f\u4e00\u4e2a\u5bf9\u6570\u7ec4\u90e8\u7f72Iterator\u63a5\u53e3\u7684\u4f8b\u5b50\uff0c\u5c3d\u7ba1\u6570\u7ec4\u539f\u751f\u5177\u6709\u8fd9\u4e2a\u63a5\u53e3\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function* makeSimpleGenerator(array){\r\n  var nextIndex = 0;\r\n\r\n  while(nextIndex &lt; array.length){\r\n    yield array[nextIndex++];\r\n  }\r\n}\r\n\r\nvar gen = makeSimpleGenerator(['yo', 'ya']);\r\n\r\ngen.next().value \/\/ 'yo'\r\ngen.next().value \/\/ 'ya'\r\ngen.next().done  \/\/ true<\/pre>\n<h3 id=\"4\u4f5c\u4e3a\u6570\u636e\u7ed3\u6784\">\uff084\uff09\u4f5c\u4e3a\u6570\u636e\u7ed3\u6784<\/h3>\n<p>Generator\u53ef\u4ee5\u770b\u4f5c\u662f\u6570\u636e\u7ed3\u6784\uff0c\u66f4\u786e\u5207\u5730\u8bf4\uff0c\u53ef\u4ee5\u770b\u4f5c\u662f\u4e00\u4e2a\u6570\u7ec4\u7ed3\u6784\uff0c\u56e0\u4e3aGenerator\u51fd\u6570\u53ef\u4ee5\u8fd4\u56de\u4e00\u7cfb\u5217\u7684\u503c\uff0c\u8fd9\u610f\u5473\u7740\u5b83\u53ef\u4ee5\u5bf9\u4efb\u610f\u8868\u8fbe\u5f0f\uff0c\u63d0\u4f9b\u7c7b\u4f3c\u6570\u7ec4\u7684\u63a5\u53e3\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function *doStuff() {\r\n  yield fs.readFile.bind(null, 'hello.txt');\r\n  yield fs.readFile.bind(null, 'world.txt');\r\n  yield fs.readFile.bind(null, 'and-such.txt');\r\n}<\/pre>\n<p>\u4e0a\u9762\u4ee3\u7801\u5c31\u662f\u4f9d\u6b21\u8fd4\u56de\u4e09\u4e2a\u51fd\u6570\uff0c\u4f46\u662f\u7531\u4e8e\u4f7f\u7528\u4e86Generator\u51fd\u6570\uff0c\u5bfc\u81f4\u53ef\u4ee5\u50cf\u5904\u7406\u6570\u7ec4\u90a3\u6837\uff0c\u5904\u7406\u8fd9\u4e09\u4e2a\u8fd4\u56de\u7684\u51fd\u6570\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">for (task of doStuff()) {\r\n  \/\/ task\u662f\u4e00\u4e2a\u51fd\u6570\uff0c\u53ef\u4ee5\u50cf\u56de\u8c03\u51fd\u6570\u90a3\u6837\u4f7f\u7528\u5b83\r\n}<\/pre>\n<p>\u5b9e\u9645\u4e0a\uff0c\u5982\u679c\u7528ES5\u8868\u8fbe\uff0c\u5b8c\u5168\u53ef\u4ee5\u7528\u6570\u7ec4\u6a21\u62dfGenerator\u7684\u8fd9\u79cd\u7528\u6cd5\u3002<\/p>\n<pre class=\"brush:js;toolbar:false\">function doStuff() {\r\n  return [\r\n    fs.readFile.bind(null, 'hello.txt'),\r\n    fs.readFile.bind(null, 'world.txt'),\r\n    fs.readFile.bind(null, 'and-such.txt')\r\n  ];\r\n}<\/pre>\n<p>\u4e0a\u9762\u7684\u51fd\u6570\uff0c\u53ef\u4ee5\u7528\u4e00\u6a21\u4e00\u6837\u7684for\u2026of\u5faa\u73af\u5904\u7406\uff01\u4e24\u76f8\u4e00\u6bd4\u8f83\uff0c\u5c31\u4e0d\u96be\u770b\u51faGenerator\u4f7f\u5f97\u6570\u636e\u6216\u8005\u64cd\u4f5c\uff0c\u5177\u5907\u4e86\u7c7b\u4f3c\u6570\u7ec4\u7684\u63a5\u53e3\u3002<\/p>\n<p class=\"post-copyright\">\u6b22\u8fce\u5206\u4eab\u672c\u6587\uff0c\u8f6c\u8f7d\u8bf7\u4fdd\u7559\u51fa\u5904\uff1a<a href=\"http:\/\/www.qdabc.cn\">\u524d\u7aefABC<\/a> &raquo; <a href=\"http:\/\/www.qdabc.cn\/?p=644\">ES6\u4e2d\u7684Generator\u51fd\u6570<\/a><\/p>","protected":false},"excerpt":{"rendered":"<p>\u5728\u6b64\u5904\u5148\u5217\u4e0b\u672c\u7bc7\u6587\u7ae0\u7684\u4e3b\u8981\u5185\u5bb9 \u7b80\u4ecb next\u65b9\u6cd5\u7684\u53c2\u6570 for\u2026of\u5faa\u73af Generator.prototype.throw() Generator.prototype.return() yield [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":87,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[143],"_links":{"self":[{"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=\/wp\/v2\/posts\/644"}],"collection":[{"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=644"}],"version-history":[{"count":3,"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=\/wp\/v2\/posts\/644\/revisions"}],"predecessor-version":[{"id":648,"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=\/wp\/v2\/posts\/644\/revisions\/648"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=\/wp\/v2\/media\/87"}],"wp:attachment":[{"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=644"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=644"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=644"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}