文件列表:

box-img-lg.png (168669, 2018-02-05)
box-img-sm.png (7492, 2018-02-05)
config (0, 2018-02-05)
config\env.js (1102, 2018-02-05)
config\jest (0, 2018-02-05)
config\jest\cssTransform.js (323, 2018-02-05)
config\jest\fileTransform.js (301, 2018-02-05)
config\paths.js (1888, 2018-02-05)
config\polyfills.js (613, 2018-02-05)
config\webpack.config.dev.js (9642, 2018-02-05)
config\webpack.config.prod.js (10068, 2018-02-05)
contracts (0, 2018-02-05)
contracts\Authentication.sol (1294, 2018-02-05)
contracts\Migrations.sol (514, 2018-02-05)
contracts\Rideshare.sol (4715, 2018-02-05)
contracts\zeppelin (0, 2018-02-05)
contracts\zeppelin\lifecycle (0, 2018-02-05)
contracts\zeppelin\lifecycle\Killable.sol (271, 2018-02-05)
contracts\zeppelin\ownership (0, 2018-02-05)
contracts\zeppelin\ownership\Ownable.sol (476, 2018-02-05)
demo1.PNG (1325429, 2018-02-05)
demo2.PNG (51986, 2018-02-05)
migrations (0, 2018-02-05)
migrations\1_initial_migration.js (129, 2018-02-05)
migrations\2_deploy_contracts.js (539, 2018-02-05)
node_modules (0, 2018-02-05)
node_modules\.bin (0, 2018-02-05)
node_modules\.bin\acorn (18, 2018-02-05)
node_modules\.bin\babylon (25, 2018-02-05)
node_modules\.bin\browserslist (22, 2018-02-05)
node_modules\.bin\cdl (22, 2018-02-05)
node_modules\.bin\cssesc (20, 2018-02-05)
node_modules\.bin\csso (16, 2018-02-05)
node_modules\.bin\detect (30, 2018-02-05)
node_modules\.bin\detect-port (30, 2018-02-05)
node_modules\.bin\errno (15, 2018-02-05)
node_modules\.bin\escodegen (29, 2018-02-05)
... ...

[](http://travis-ci.org/kriskowal/q) [](https://cdnjs.com/libraries/q.js) If a function cannot return a value or throw an exception without blocking, it can return a promise instead. A promise is an object that represents the return value or the thrown exception that the function may eventually provide. A promise can also be used as a proxy for a [remote object][Q-Connection] to overcome latency. [Q-Connection]: https://github.com/kriskowal/q-connection On the first pass, promises can mitigate the “[Pyramid of Doom][POD]”: the situation where code marches to the right faster than it marches forward. [POD]: http://calculist.org/blog/2011/12/14/why-coroutines-wont-work-on-the-web/ ```javascript step1(function (value1) { step2(value1, function(value2) { step3(value2, function(value3) { step4(value3, function(value4) { // Do something with value4 }); }); }); }); ``` With a promise library, you can flatten the pyramid. ```javascript Q.fcall(promisedStep1) .then(promisedStep2) .then(promisedStep3) .then(promisedStep4) .then(function (value4) { // Do something with value4 }) .catch(function (error) { // Handle any error from all above steps }) .done(); ``` With this approach, you also get implicit error propagation, just like `try`, `catch`, and `finally`. An error in `promisedStep1` will flow all the way to the `catch` function, where it’s caught and handled. (Here `promisedStepN` is a version of `stepN` that returns a promise.) The callback approach is called an “inversion of control”. A function that accepts a callback instead of a return value is saying, “Don’t call me, I’ll call you.”. Promises [un-invert][IOC] the inversion, cleanly separating the input arguments from control flow arguments. This simplifies the use and creation of API’s, particularly variadic, rest and spread arguments. [IOC]: http://www.slideshare.net/domenicdenicola/callbacks-promises-and-coroutines-oh-my-the-evolution-of-asynchronicity-in-javascript ## Getting Started The Q module can be loaded as: - A ``