let draw =
  () {
    case Dom.Canvas.fromDomElement(canvas) {
      Maybe::Just(el) =>
        {
          let isInStroke =
            el
            |> Canvas.rect(10, 10, 100, 100)
            |> Canvas.stroke()
            |> Canvas.isPointInStroke(50, 10)
          el
          |> Canvas.fillText("(50, 10) is in stroke: #{Bool.toString(isInStroke)}", 150, 50)
          ""
        }
      Maybe::Nothing =>
        ""
    }
  }
{
  await Timer.timeout(0)
  draw()
}
<canvas as canvas/>