css

    while (b - a).abs() > EPSILON {
        let c = a + (a - b) * f_a / (f_b - f_a);
        let f_c = J(c);
        if f_c * f_b == 0.0 {
            a = b;
            f_a = f_b;
        } else {
            f_a /= 2.0;
        }
        b = c;
        f_b = f_c;
    }