Function parseUnitToken

src/compute-engine/numerics/unit-data.ts:514–524

* Parse a unit token like `"s^2"` into a MathJSON expression. * A plain unit (no `^`) stays as a string; `"s^2"` becomes * `["Power", "s", 2]`.

(token: string)

    }
    return result;
  }

  if (op === 'Divide') {
    if (expr.length !== 3) return null;
    const sa = getExpressionScale(expr[1]);
    const sb = getExpressionScale(expr[2]);
    if (sa === null || sb === null || sb === 0) return null;
    return sa / sb;
  }

  if (op === 'Power') {
    if (expr.length !== 3) return null;
    const s = getExpressionScale(expr[1]);
    const exp = expr[2];