let draw =
  () {
    case Dom.Canvas.fromDomElement(canvas) {
      Maybe::Just(el) =>
        {
          // Quadratic Bézier curve
          el
          |> Canvas.beginPath
          |> Canvas.moveTo(50, 20)
          |> Canvas.quadraticCurveTo(230, 30, 50, 100)
          |> Canvas.stroke
          // Start and end points
          el
          |> Canvas.setFillStyle(CanvasFillStyle::String("blue"))
          |> Canvas.beginPath
          |> Canvas.arc(50, 20, 5, 0, 2 * `Math.PI`)
          |> Canvas.arc(50, 100, 5, 0, 2 * `Math.PI`)
          |> Canvas.fill
          // Control point
          el
          |> Canvas.setFillStyle(CanvasFillStyle::String("red"))
          |> Canvas.beginPath
          |> Canvas.arc(230, 30, 5, 0, 2 * `Math.PI`)
          |> Canvas.fill
          ""
        }
      Maybe::Nothing =>
        ""
    }
  }
{
  await Timer.timeout(0)
  draw()
}
<canvas as canvas/>