sflow - Stream Flow 🚀

sflow is a powerful and highly-extensible library designed for processing and manipulating streams of data effortlessly based on WebStream. Inspired by the functional programming paradigm, it provides a rich set of utilities for transforming streams, including chunking, filtering, mapping, reducing, among many others. It's a perfect companion for those who work extensively with streams and want to make their data processing pipelines more efficient and concise.

ONLINE DEMO avaliable here! - sflow online Examples and Use Cases

Features

• Chunking and buffering: Easily divide your stream into chunks based on different criteria such as count, intervals, custom conditions, etc.

• Transformations: Map, filter, reduce, and various other transformations to process your stream data.

• Stream utilities: Merge, throttle, debounce, and more utilities for advanced stream controls.

• Error handling: Prevent or handle errors during stream processing, ensuring robustness.

• Integration with other libraries: Seamlessly integrates with tools like web-streams-extensions, making it versatile for different streaming needs.

• TypeScript support: Fully typed for a richer developer experience and better code quality.

Get Started

Installation

Install sflow using npm or bun:

npm install sflow

# or if you are using bun

bun add sflow

Basic Usage

Here's a basic example of how to use sflow to process a stream:

import { sflow } from "sflow";

async function run() {
  let result = await sflow([1, 2, 3, 4])
    .map((n) => n * 2)
    .log() // this stage prints 2, 4, 6, 8
    .filter((n) => n > 4)
    .log() // this stage prints 6, 8
    .reduce((a, b) => a + b, 0) // first emit 0+6=6, second emit 0+6+8=14
    .log() // this stage prints 6, 14
    .toArray();

  console.log(result); // Outputs: [6, 14]
}

await run();

API Overview

Initialization

Initialize a flow from various types of data sources:

import { sflow } from "sflow";

// From an array
const flow1 = sflow([1, 2, 3, 4]);

// From a promise
const flow2 = sflow(Promise.resolve([1, 2, 3, 4]));

// From an async iterable
async function* asyncGenerator() {
  yield 1;
  yield 2;
  yield 3;
}
const flow3 = sflow(asyncGenerator());

Transformations

Transform your flow with various transformation methods:

// Mapping
flow1.map((n) => n * 2);

// Filtering
flow1.filter((n) => n % 2 === 0);

// Reducing
flow1.reduce((a, b) => a + b, 0);

Chunking, Buffering, and Grouping

sflow provides methods for chunking, buffering, and grouping data:

// Chunking by count
flow1.chunk(2); // [[1, 2], [3, 4]]

// Buffering within a time interval
flow1.chunkByInterval(1000);

// Custom chunking
flow1.chunkBy((x) => Math.floor(x / 2));

Advanced Utilities

sflow comes with a plethora of utilities to manipulate streams efficiently:

// Throttling
flow1.throttle(100);

// Debouncing
flow1.debounce(200);

// Converting to array
flow1.toArray();

// Merging multiple streams
const mergedFlow = sflow([flow1, flow2]).merge();

// Use chunkIf to split tokens by line
await sflow("a,b,c\n\n1,2,3\nd,s,f".split(""))
  .through(chunkIfs((e: string) => e.indexOf("\n") === -1))
  .map((chars) => chars.join(""))
  .toArray(); // ["a,b,c\n",'\n', "1,2,3\n", "d,s,f"]

Type-Safe Enhancements

With TypeScript, sflow ensures your transformations are type-safe:

import { sflow } from "sflow";

const typedFlow = sflow([{ a: 1, b: [1, 2, 3] }])
  .unwind("b") // Use `unwind` for objects with nested arrays
  .mapAddField("newField", (item) => item.a + item.b);

Contributing

Contributions to sflow are always welcome! If you have any ideas, suggestions, or bug reports, feel free to open an issue on GitHub or submit a pull request.

Try to create your first PR start from here! https://github.dev/snomiao/sflow

2. Join sflow Community by Post Comments here:

• Welcome to sflow Discussions! · snomiao/sflow · Discussion #2

References

• Infinite Streams with Elixir
• web-streams-extensions - npm
• $unwind (aggregation) - MongoDB Manual v7.0
• Introducing sflow: A New Era of Web Stream Processing for TypeScript/JavaScript Developers! : r/javascript

License

sflow is released under the MIT License. See the LICENSE file for more details.

sflow aims to simplify stream processing and bring functional programming paradigms to modern JavaScript and TypeScript development. Happy streaming! 🚀