https://github.com/biggyspender/blinq
TypeScript implementation of Microsoft dotnet's LINQ to Objects using ES6 iterables
https://github.com/biggyspender/blinq
iterable iterator javascript linq linq-to-objects typescript-library
Last synced: about 1 month ago
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TypeScript implementation of Microsoft dotnet's LINQ to Objects using ES6 iterables
- Host: GitHub
- URL: https://github.com/biggyspender/blinq
- Owner: biggyspender
- License: mit
- Created: 2018-10-21T13:20:34.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2022-12-08T19:28:21.000Z (over 2 years ago)
- Last Synced: 2025-04-10T09:22:03.665Z (about 1 month ago)
- Topics: iterable, iterator, javascript, linq, linq-to-objects, typescript-library
- Language: TypeScript
- Homepage: https://biggyspender.github.io/blinq/
- Size: 1.19 MB
- Stars: 13
- Watchers: 2
- Forks: 0
- Open Issues: 21
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
## A strongly-typed TypeScript implementation of Microsoft dotnet's LINQ to Objects using ES6 iterables.
With the advent of javascript iterators and generators, its possible to pipe sequences through a bunch of transformations without materializing collections (arrays) for the intermediate steps. This library attempts to recreate the dotnet linq-to-objects api to provide a number of standard operations on iterable sequences.
The following operations are available, and the user can optionally supply their own `EqualityComparer` (implementing `equals` and `getHashCode`) when using the set-based operations.
```aggregate, all, any, append, average, concat, count, defaultIfEmpty, distinctBy, distinct, elementAt, except, firstOrDefault, first, flatten, forEach, fullOuterGroupJoin, fullOuterJoin, groupAdjacent, groupBy, groupJoin, intersect, isSubsetOf, isSupersetOf, join, lastOrDefault, last, leftOuterJoin, maxBy, max, minBy, min, orderBy / orderByDescending / thenBy / thenByDescending, preprend, reverse, selectMany, select, sequenceEqual, singleOrDefault, single, skip, skipWhile, sum, take, takeWhile, toArray, toLookup, toMap, toSet, union, where, zipAll, zip```
[](https://travis-ci.org/biggyspender/blinq)
[](https://coveralls.io/github/biggyspender/blinq?branch=master)
NPM package can be downloaded [here](https://www.npmjs.com/package/blinq).
### documentation
Generated documentation can be found at [https://biggyspender.github.io/blinq/](https://biggyspender.github.io/blinq/)
### How?
Import blinq ES6 style:
import {
blinq,
range,
empty,
fromGenerator,
fromSingleValue,
repeatGenerate,
repeat,
EqualityComparer,
hashString
} from "blinq";
or nodejs style:
const {
blinq,
range,
empty,
fromGenerator,
fromSingleValue,
repeatGenerate,
repeat,
EqualityComparer,
hashString
} = require("blinq")
Now, just wrap your iterable with a call to `blinq(myIterable)`, and start transforming your data:
const someNumbers = [1, 2, 3, 4];
const squares = blinq(someNumbers).select(n => n * n);
for(let v of squares){
console.log(v);
}
...or if you'd like an array of your results, you can materialize a blinq query with the `.toArray()` method:
const someNumbers = range(1, 4);
const squaresBelowTen = someNumbers.select(n => n * n).where(n => n < 10);
const arr = squaresBelowTen.toArray();
console.log(arr);
or even spread your results into an array:
const arr2 = [...squaresBelowTen]
### A case-insensitive set, using EqualityComparer
const names = ["zebra", "antelope", "ardvaark", "tortoise", "turtle", "dog", "frog"]
const comparer: EqualityComparer = {
equals: (a, b) => a.toLowerCase() === b.toLowerCase(),
getHashCode: (x) => hashString(x.toLowerCase())
}
const set = blinq(names).toSet(comparer)
expect(set.has("DOg")).toBeTruthy()
#### More examples:
Let's make a collection of cars:
const cars = [{
manufacturer:"Ford",
model:"Escort"
},{
manufacturer:"Ford",
model:"Cortina"
},{
manufacturer:"Renault",
model:"Clio"
},{
manufacturer:"Vauxhall",
model:"Corsa"
},{
manufacturer:"Ford",
model:"Fiesta"
},{
manufacturer:"Fiat",
model:"500"
}
];
...and sort them by manufacturer, and then by model:
const orderedCars = blinq(cars).orderBy(c => c.manufacturer).thenBy(c => c.model);
console.log(orderedCars.toArray());
Or we could count the number of cars for each manufacturer:
const carsPerManufacturer = blinq(cars)
.groupBy(c => c.manufacturer)
.select(g => ({
manufacturer:g.key,
count:g.count()
}))
.orderBy(c => c.manufacturer);
for(var c of carsPerManufacturer){
console.log(`${c.manufacturer} : ${c.count}`);
}
### What next?
The [tests](https://github.com/biggyspender/blinq/tree/master/test) for this project are kept up to date and are the best place to look for other examples.
### acknowledgements
Created using the wonderful [https://github.com/alexjoverm/typescript-library-starter](https://github.com/alexjoverm/typescript-library-starter).