Roma P. rpominov

A lot of people mentioned other immutable JS libraries after reading my post. I thought it would be good to make a list of available ones.

There are two types of immutable libraries: simple helpers for copying JavaScript objects, and actual persistent data structure implementations. My post generally analyzed the tradeoffs between both kinds of libraries and everything applies to the below libraries in either category.

Libraries are sorted by github popularity.

Persistent Data Structures w/structural sharing

This is a proposal for a lightning talk at the Reactive 2015 conference.

NOTE: If you like this, star ⭐ the Gist - the amount of stars decides whether it makes the cut!

Rapid prototyping with Relay

Relay makes data fetching in React apps simpler, by letting you declare the data needs of your components instead of writing complex imperative code. React, Relay, GraphQL and the other complementary tools are changing how apps are built.

Pattern Matching

This is a strawman proposal for adding pattern matching to ECMAScript. Pattern matching is useful for matching a value to some structure in a similar way to destructuring. The primary difference between destructuring and pattern matching are the use cases involved - destructuring is useful for binding pieces out of larger structures whereas pattern matching is useful for mapping a value's structure to data or a set of behaviors. In practice this means that destructuring tends to allow many shapes of data and will do its best to bind something out of it, whereas pattern matching will tend to be more conservative.

Additionally, the power of pattern matching is increased substantially when values are allowed to participate in the pattern matching semantics as a matcher as well as a matchee. This proposal includes the notion of a pattern matching protocol - a symbol method that can be implemented by objects that enables developers to use those values in pattern matching. A common scenario w

Broken Promises

Technical Decision

Eliminate all promises from application.

TL;DR

The Promise API is the source of many confusing errors in our application, using node style callbacks eliminates the issue without reducing code quality.

Applied Functional Programming with Scala - Notes

1. Mastering Functions

A function is a mapping from one set, called a domain, to another set, called the codomain. A function associates every element in the domain with exactly one element in the codomain. In Scala, both domain and codomain are types.

val square : Int => Int = x => x * x

This API was removed in React 17

Interaction tracing with React

React recently introduced an experimental profiler API. After discussing this API with several teams at Facebook, one common piece of feedback was that the performance information would be more useful if it could be associated with the events that caused the application to render (e.g. button click, XHR response). Tracing these events (or "interactions") would enable more powerful tooling to be built around the timing information, capable of answering questions like "What caused this really slow commit?" or "How long does it typically take for this interaction to update the DOM?".

With version 16.4.3, React added experimental support for this tracing by way of a new NPM package, scheduler. However the public API for this package is not yet finalized and will likely change with upcoming minor releases, so it should be used with caution.

	import React from 'react'

	const provideContext = (contextKey, contextType) => (
	React.createClass({
	childContextTypes: {
	[contextKey]: contextType
	},

	getChildContext() {
	const { children, ...props } = this.props

	{
	"stage": 2,
	"loose": "all"
	}