ttokutake / js-kasen

The library of collection methods

Kasen

Kasen is the library of collection methods which is inspired by Lodash, Immutable, Rambda, Scala and Elixir.

Note that Kasen is experimental state. APIs can be changed in the future.

What does Kasen mean?

"Kasen" means "underscore" in Japanese 😛

Installation

npm install kasen

Import

• ES Modules: import Kasen from "kasen";
• CommonJS: const Kasen = require("kasen");

Example

const result1 = Kasen.map({ a: 1, b: 2, c: 3 }, v => v + 1);
console.log(result1); // => { a: 2, b: 3, c: 4 }

const result2 = Kasen([1, 2, 3])
  .filter(v => v % 2 === 1)
  .map(v => v + 1)
  .toJS();
console.log(result2); // => [2, 4]

Feature

1. Immutability: Methods do not mutate an input collection.

   const input = [1, 2, 3];
   const result = Kasen.push(input, 4);
   console.log(input); // => [1, 2, 3]
   console.log(result); // => [1, 2, 3, 4]

2. Lazy Evaluation: Method chaining does not process unnecessary calculations.

   const result = Kasen([1, 2, 3])
     .map(v => {
       console.log(v);
       return v + 1;
     })
     .every(v => v % 2 === 0);
   // => 1
   // => 2
   console.log(result); // => false

3. Great Selection of Methods: Kasen will have a lot of collection methods.

   • 96 methods for Array.
   • 57 methods for Object.

4. Light Weight: Kasen will be light weight library.

   • Kasen is 68 KB now.

APIs

Note that documentation is under construction.

• APIs for Array
• APIs for Object

Contribution

TBD

License

Kasen is MIT-licensed.

js-kasen's Issues

Prepare .d.ts files

Absorb standard methods and Ramda methods

Divide a job in CircleCI

Use npm-run-all?

• build sources before tests
• should use NODE_ENV in webpack.config.js

Use service like Greenkeeper

• Greenkeeper
• David

Do not create function in constructor

Enable Map and Set

Introduce Codecov

(vs Coveralls)

Implement Iterator

Use AppVeyor instead of CircleCI

memoize()

• memoize() at Ramda
• cacheResult() at Immutable

Remove useless super methods

• Collection.filter()
• Collection.update()
• etc.

なんか余分そうなパッケージを消したい

Babel 7でJestを使うために入れたパッケージが気に入らないのだ
https://jestjs.io/docs/en/getting-started#using-babel

• babel-jest
• babel-core@^7.0.0-bridge.0

Create methods "for" version

Enable to call constructor without "new" like Immutable.js

• Search "js call class constructor without new"
  https://stackoverflow.com/questions/30689817/es6-call-class-constructor-without-new-keyword
• Build of Immutable.js
  https://github.com/facebook/immutable-js/blob/master/resources/rollup-config.js

Implement pull streaming way instead of triple "for" loop

What does "kasen" mean ?

Hi, I'm really interested in your awesome library!! 🎉
I would like to know the "kasen" mean. Would you update README.md, and write down the origin of it and your elegant thoughts ?

"if" methods accept function

Example

Kasen([1, 2, 3]).mapIf(array => array.length, v => v + 1).toJs()

Formatter for JSON and YAML

Should require Kasen without "default" in CommonJS

Allow to throw Errors in Collection

its stack trace is easy to see.
summarize errors and reduce message typo.

Do not use clone()

concat()

[].concat([1, 2, 3], 4) // => [1, 2, 3, 4]

Add links to other library's API to API docs

Performance test

Type check for each method

Create "for" version methods

Test for main browsers

• Chrome
• FireFox
• Safari
• Edge, IE (if needed)

Use TypeScript and webpack

https://ics.media/entry/16329

Use Iterator

なんかめっちゃ勘違いしていたが、Map用のIteratorとかメソッド毎に用意してやる感じだったのを思い出した...
他のライブラリー参考にして実装してみる。