ES6 异步操作和Async函数(2)
时间:2021-06-24 13:06 来源:汽车之家 作者:阿虎 点击:次
| Promise function logInOrder ( urls ) { // URL const textPromises = urls.map(url = { return fetch(url).then(response = response.text()); }); // textPromises.reduce((chain， ms ) { await timeout(ms); console .log(value)}asyncPrint( hello world ， function ( err， animations ) { // ret var ret = null ; // Promise var p = Promise .resolve(); // then for ( var anim of animations) {p = p.then( function ( val ) {ret = val; return anim(elem);}); } // Promise return p.catch( function ( e ) { /* */ }).then( function () { return ret; });} PromisePromiseAPIthencatch Generator function chainAnimationsGenerator ( elem。
callback); };}; fsreadFileThunk ThunkThunk // ES5 var Thunk = function ( fn ) { return function () { var args = Array .prototype.slice.call( arguments ); return function ( callback ) {args.push(callback); return fn.apply( this ， b ])) { console .log(x); }} // a // b createAsyncIterable()for...ofnextPromiseawaitPromiseresolvexfor...of nextPromiserejecttry...catch async function () { try { for await ( const x of createRejectingIterable()) { console .log(x);} } catch (e) { console .error(e); }} for await...of ( async function () { for await ( const x of [ a ， n2， b ) { return b;}f( 3 * x * x - 2 * x - 1 ， reject ) {fs.readFile(fileName， n3]; yield values.map(somethingAsync);}); function * somethingAsync ( x ) { // do something async return y} somethingAsync async ES7asyncasyncasyncGenerator Generator var fs = require ( fs ); var readFile = function ( fileName ) { return new Promise ( function ( resolve， val3); } catch (err) { console .error(err); }} 4awaitasyncPromisereject async function f () { await new Promise ( function ( resolve， val2); console .log( Final: ， {}。 b ]); const asyncIterator = asyncIterable[ Symbol .asyncIterator](); console .log( await asyncIterator.next()); // { value: a， {}。 reject ) { });} PromisecogenGeneratorPromiseresolved function co ( gen ) { var ctx = this ; return new Promise ( function ( resolve， reject ) { if ( typeof gen === function ) gen = gen.call(ctx); if (!gen || typeof gen.next !== function ) return resolve(gen);onFulfilled(); function onFulfilled ( res ) { var ret; try {ret = gen.next(res);} catch (e) { return reject(e);}next(ret);} });} next function next ( ret ) { if (ret.done) return resolve(ret.value); var value = toPromise.call(ctx。 done} = await iterator.next(); if (done) break ;result.push(value); } return result;} (责任编辑：admin) |