Edouard isthatcentered

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

	export interface None {
	readonly _tag: "None"
	}

	export interface Some<A> {
	readonly _tag: "Some"
	readonly value: A
	}

	export type Option<A> = None \| Some<A>


	// We model the call stack using a linked list of Generators
	// Each Generator has a _return field pointing back to its parent

	function stepGen(gen, arg) {
	const {done, value} = gen.next(arg)
	if(done) {
	if(gen._return) {
	stepGen(gen._return, value)
	}