nyinyithann / SeqJS

Pipeline Operations for working with values of type Seq.

This Project is only for educational purpose.

  SeqJS: Pipeline Operations for working with values of type Seq

SeqJS contains operations for working with values of type Seq which is a container of a series of elements. Types of a seq's elements are not fixed. Individual seq elements are computed only as required. Seq conforms iterable and iterator protocols of JavaScript.

GitHub CI Status

Usage

A seq instance can be constructed as follows:

// An empty sequence
let seq = new Seq();
console.log([...seq]);
// => [];

// A sequence wrapped an array
let seq = new Seq([1, 2, 3]);
console.log([...seq]);
// => [1, 2, 3]

// A sequence wrapped a generator function
let seq = new Seq(function * () {
    yield 1;
    yield 2;
    yield 3;
});
console.log([...seq]);
// => [1, 2, 3]

// A sequence wrapped an iterator
const iterator = {
    i: 1,
    [Symbol.iterator] () {
        return this;
    },
    next () {
        if (this.i <= 3) {
            return { value: this.i++, done: false };
        }
        return { done: true };
    },
};
let seq = new Seq(iterator);
console.log([...seq]);
// => [1, 2, 3]

Seq is multi-iterable.

let seq = new Seq([1, 2, 3]);
for (const item of seq) {}
for (const item of seq) {}
console.log([...seq]);        
console.log([...seq]);  
// => [1, 2, 3]
// => [1, 2, 3]

Seq is closable.

let seq = new Seq([1, 2, 3, 4, 5]);
for (const item of seq) {
    if (item == 2) break;
}
console.log([...seq]);
// => [1, 2, 3, 4, 5]

API Document

Please read the API Docs for full details.

Author

Nyi Nyi Than - @nyinyithann

Credit

• Exploring ES6 By Dr. Axel Rauschmayer
• Understanding ECMAScript 6 By Nicholas C. Zakas
• Collection Pipeline by Martin Fowler
• javascript.info
• Iteration protocols
• F# Seq Module

License

MIT