Run results for: Discriminated Union vs InstanceOf

Run details:

User agent: Mozilla/5.0 (Linux; Android 10; POCO M2 Pro) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/95.0.4638.74 Mobile Safari/537.36

Browser: Chrome Mobile 95

Operating system: Android

Device Platform: Mobile

Date tested: 3 years ago

Test name	Executions per second
Classes	7023.5 Ops/sec
Union	6517.6 Ops/sec

Script Preparation code:

function Shape() {}
function Circle() {}
Circle.prototype = new Shape();

function Square() {}
Square.prototype = new Shape()

function Rectangle () {}
Rectangle.prototype = new Square();

function circle() {
  return { kind: 0 };
}

function isCircle(t) {
  return t.kind === 0;
}

function square() {
  return { kind: 1 }
}

function isSquare(t) {
  return t.kind === 1;
}

function rectangle() {
  return { kind: 2 }
}

function isRectangle(t) {
  return t.kind === 2;
}

Tests:

Classes
const c = new Circle(); const s = new Square(); const r = new Rectangle(); console.log(c instanceof Circle); console.log(c instanceof Square); console.log(s instanceof Circle); console.log(s instanceof Square); console.log(r instanceof Rectangle);
Union
const c = circle(); const s = square(); const r = rectangle(); console.log(isCircle(c)); console.log(isSquare(c)); console.log(isCircle(s)); console.log(isSquare(s)); console.log(isRectangle(r));

Run results for: Discriminated Union vs InstanceOf

Classes

Union