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