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| author | Florian Dold <florian.dold@gmail.com> | 2017-05-03 15:35:00 +0200 | 
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| committer | Florian Dold <florian.dold@gmail.com> | 2017-05-03 15:35:00 +0200 | 
| commit | de98e0b232509d5f40c135d540a70e415272ff85 (patch) | |
| tree | a79222a5b58484ab3b80d18efcaaa7ccc4769b33 /node_modules/co/Readme.md | |
| parent | e0c9d480a73fa629c1e4a47d3e721f1d2d345406 (diff) | |
node_modules
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| -rw-r--r-- | node_modules/co/Readme.md | 212 | 
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diff --git a/node_modules/co/Readme.md b/node_modules/co/Readme.md new file mode 100644 index 000000000..c1d4882a1 --- /dev/null +++ b/node_modules/co/Readme.md @@ -0,0 +1,212 @@ +# co + +[![Gitter][gitter-image]][gitter-url] +[![NPM version][npm-image]][npm-url] +[![Build status][travis-image]][travis-url] +[![Test coverage][coveralls-image]][coveralls-url] +[![Downloads][downloads-image]][downloads-url] + +  Generator based control flow goodness for nodejs and the browser, +  using promises, letting you write non-blocking code in a nice-ish way. + +## Co v4 + +  `co@4.0.0` has been released, which now relies on promises. +  It is a stepping stone towards [ES7 async/await](https://github.com/lukehoban/ecmascript-asyncawait). +  The primary API change is how `co()` is invoked. +  Before, `co` returned a "thunk", which you then called with a callback and optional arguments. +  Now, `co()` returns a promise. + +```js +co(function* () { +  var result = yield Promise.resolve(true); +  return result; +}).then(function (value) { +  console.log(value); +}, function (err) { +  console.error(err.stack); +}); +``` + +  If you want to convert a `co`-generator-function into a regular function that returns a promise, +  you now use `co.wrap(fn*)`. + +```js +var fn = co.wrap(function* (val) { +  return yield Promise.resolve(val); +}); + +fn(true).then(function (val) { + +}); +``` + +## Platform Compatibility + +  `co@4+` requires a `Promise` implementation. +  For versions of node `< 0.11` and for many older browsers, +  you should/must include your own `Promise` polyfill. + +  When using node 0.11.x or greater, you must use the `--harmony-generators` +  flag or just `--harmony` to get access to generators. + +  When using node 0.10.x and lower or browsers without generator support, +  you must use [gnode](https://github.com/TooTallNate/gnode) and/or [regenerator](http://facebook.github.io/regenerator/). + +  io.js is supported out of the box, you can use `co` without flags or polyfills. + +## Installation + +``` +$ npm install co +``` + +## Associated libraries + +Any library that returns promises work well with `co`. + +- [mz](https://github.com/normalize/mz) - wrap all of node's code libraries as promises. + +View the [wiki](https://github.com/visionmedia/co/wiki) for more libraries. + +## Examples + +```js +var co = require('co'); + +co(function *(){ +  // yield any promise +  var result = yield Promise.resolve(true); +}).catch(onerror); + +co(function *(){ +  // resolve multiple promises in parallel +  var a = Promise.resolve(1); +  var b = Promise.resolve(2); +  var c = Promise.resolve(3); +  var res = yield [a, b, c]; +  console.log(res); +  // => [1, 2, 3] +}).catch(onerror); + +// errors can be try/catched +co(function *(){ +  try { +    yield Promise.reject(new Error('boom')); +  } catch (err) { +    console.error(err.message); // "boom" + } +}).catch(onerror); + +function onerror(err) { +  // log any uncaught errors +  // co will not throw any errors you do not handle!!! +  // HANDLE ALL YOUR ERRORS!!! +  console.error(err.stack); +} +``` + +## Yieldables + +  The `yieldable` objects currently supported are: + +  - promises +  - thunks (functions) +  - array (parallel execution) +  - objects (parallel execution) +  - generators (delegation) +  - generator functions (delegation) + +Nested `yieldable` objects are supported, meaning you can nest +promises within objects within arrays, and so on! + +### Promises + +[Read more on promises!](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise) + +### Thunks + +Thunks are functions that only have a single argument, a callback. +Thunk support only remains for backwards compatibility and may +be removed in future versions of `co`. + +### Arrays + +`yield`ing an array will resolve all the `yieldables` in parallel. + +```js +co(function* () { +  var res = yield [ +    Promise.resolve(1), +    Promise.resolve(2), +    Promise.resolve(3), +  ]; +  console.log(res); // => [1, 2, 3] +}).catch(onerror); +``` + +### Objects + +Just like arrays, objects resolve all `yieldable`s in parallel. + +```js +co(function* () { +  var res = yield { +    1: Promise.resolve(1), +    2: Promise.resolve(2), +  }; +  console.log(res); // => { 1: 1, 2: 2 } +}).catch(onerror); +``` + +### Generators and Generator Functions + +Any generator or generator function you can pass into `co` +can be yielded as well. This should generally be avoided +as we should be moving towards spec-compliant `Promise`s instead. + +## API + +### co(fn*).then( val => ) + +Returns a promise that resolves a generator, generator function, +or any function that returns a generator. + +```js +co(function* () { +  return yield Promise.resolve(true); +}).then(function (val) { +  console.log(val); +}, function (err) { +  console.error(err.stack); +}); +``` + +### var fn = co.wrap(fn*) + +Convert a generator into a regular function that returns a `Promise`. + +```js +var fn = co.wrap(function* (val) { +  return yield Promise.resolve(val); +}); + +fn(true).then(function (val) { + +}); +``` + +## License + +  MIT + +[npm-image]: https://img.shields.io/npm/v/co.svg?style=flat-square +[npm-url]: https://npmjs.org/package/co +[travis-image]: https://img.shields.io/travis/tj/co.svg?style=flat-square +[travis-url]: https://travis-ci.org/tj/co +[coveralls-image]: https://img.shields.io/coveralls/tj/co.svg?style=flat-square +[coveralls-url]: https://coveralls.io/r/tj/co +[downloads-image]: http://img.shields.io/npm/dm/co.svg?style=flat-square +[downloads-url]: https://npmjs.org/package/co +[gitter-image]: https://badges.gitter.im/Join%20Chat.svg +[gitter-url]: https://gitter.im/tj/co?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge  | 
