JSFiddle - React, Tailwind, and code Playground

JavaScript

L = text.sourceText.length;
It = time - thisLayer.inPoint;
T = It * effect("Speed")("Slider");
F = Math.round(It % 1);

if (F == 1 | (T, 0)) {
  Fl = "|";
} else {
  Fl = " ";
}
substr(0, T) + Fl