node-promisePromises 实现

node-promise 在 Node.js 平台上提供了完整的 Promises 的实现。

The node-promise module features a promise implementation with:

• Chainable promises


• Promises throw errors if an error handler is not provided


• CommonJS promise proposal [1] compliant


• Immutable once fulfilled to reduce possible side-effects


• Promises can be used securely (as separate resolver/promise pairs in ocap situations)


• Backwards compatibility where possible (addCallback, addErrback, emitSuccess, and emitError should still behave as expected)

Utility functions, including:

• when() - Normalization of sync (normal values) and async (promises)


• all() - Create a promise that accumulate multiple concurrent promises


• first() - Find the first promise to be fulfilled in a group of promises


• seq() - Sequentially execute a set of promise returning functions


• delay() - Returns a promise that is fulfilled after a given amount of time


• execute() - Executes a function that takes a callback and returns a promise (thank you Benjamin Thomas for providing this)

示例代码：

var Promise = require("promise").Promise;

var promise = new Promise();

asyncOperation(function(){

  Promise.resolve("succesful result");

});

promise -> given to the consumer