let draw =
  () {
    case Dom.Canvas.fromDomElement(canvas) {
      Maybe::Just(el) =>
        {
          let x =
            175
          el
          |> Canvas.beginPath()
          |> Canvas.moveTo(x, 0)
          |> Canvas.lineTo(x, 150)
          |> Canvas.stroke()
          el
          |> Canvas.setFont("30px serif")
          el
          |> Canvas.setTextAlign(CanvasTextAlign::Left)
          |> Canvas.fillText("left-aligned", x, 40)
          el
          |> Canvas.setTextAlign(CanvasTextAlign::Center)
          |> Canvas.fillText("center-aligned", x, 85)
          el
          |> Canvas.setTextAlign(CanvasTextAlign::Right)
          |> Canvas.fillText("right-aligned", x, 130)
          ""
        }
      Maybe::Nothing =>
        ""
    }
  }
{
  await Timer.timeout(0)
  draw()
}
<canvas as canvas width="350"/>