A full port of LINQ for javascript. It works fully in 'lazy' mode for the best performance.
This library is written in ES6 and transpiled using Babel. It implements all API from .Net static class System.Linq.Enumerable.
By levering the power of generator in ES6, this library works in a lazy(or deferred) way as in .NET -- Instead of doing computing on the whole sequence at once, it would only do necessary computing while you iterating through the sequence.
The code is written is ES6 and transpiled into different format so you can easily integrate it into your project.
src/linq.js: Source code written in ES6. You could choose to use this file directly.linq.js: Transpiled with Babel runtime mode. Use in server side or in browser with proper module loader.linq-browser.js: Transpiled with Babel. Use in browser withbrowser-polyfill.js.
Details are explained below:
- Install with
npm
npm install lazy-linq requireand use it
var linq = require('lazy-linq');
var data = linq.asEnumerable([1, 2, 3]);
data.select(function(x) { return x * 2}).forEach(function(x) { console.log(x); });
// output will be:
// 2
// 4
// 6- Install with
bower
bower install lazy-linqThis would also auto install the dependency babel-polyfill.
- Include
browser-polyfill.jsand 'linq-browser.js' to yourindex.html.
<script src="../bower_components/babel-polyfill/browser-polyfill.js"></script>
<script src="../bower_components/lazy-linq/linq-browser.js"></script>- Use it in your js files
var data = linq.asEnumerable([1, 2, 3]);
data.select(function(x) { return x * 2}).forEach(function(x) { console.log(x); });
// output will be:
// 2
// 4
// 6You should use the linq code written in ES6 rather than the transpiled one and feed it to your ES6 transpiling engine along with all your other js files.
- suggest to copy the source file to 'local' location first. This could avoid many problems...
gulp.src('node_modules/lazy-linq/src/linq.js')
.pipe(gulp.dest('src/app/components/linq/'));importit in yourindex.js
// assuming index.js is in 'src/app/' folder
import * as linq from 'components/linq/linq';
// then you could attach 'linq' to global namespace for convenience:
this.linq = linq;
// or any other way suiting your code. E.g. in `angular`:
angular.module('myModule').constant('linq', linq); // make 'linq' be injectable in controller/service/etc.Using webpack and babel-loader (with runtime option)
- Simply
importthe transpiled linq.js in youindex.js
// assuming index.js is in 'src/app/' folder
import * as linq from '../../node_components/lazy-linq/linq';That's it. webpack should be able to check dependencies and pack linq.js and babel runtime together into your packed index.js.
// create a lazy range of 1 ~ 100000
var seq = linq.range(1, 100000);
// create a enumerable object which WILL but NOT YET find all even numbers in seq
var even = seq.where(function(x) { return x % 2 === 0; });
// find the first 100 even number.
var count = 0;
even.forEach(function(x) {
console.log(x);
if (++count >= 100) return;
});
// use "even" again will cause it to be evaluated from start.
// also find the first 100 even numbers and put them to an actual array.
var top100_even = even.take(100).toArray();// generate a lazy sequence of [0, ... , 9]
var seq = linq.range(0, 10);
// generate a lazy sequence of [1, 1, 1, 1, 1]
var seq = linq.repeat(1, 5);
// generate a lazy empty sequence
var seq = linq.empty();// this will install asEnumerable() for `Array` and `String`
linq.installAsEnumerable();
// then you can do this
[1, 2, 3].asEnumerable().where(....)
// if you have a custom class with iterator
class MyCollection {
[Symbol.iterator]: function* () { ... }
}
// you could also install asEnumerable() for it
linq.installAsEnumerable(MyCollection);Coming soon...