def gen_range_str(min, max):
    """
    Generates a string that shows a minimum and maximum value, as well as the range.

    Example:
    ``<min> |-- <range> --| <max>``

    Parameters
    ----------
        min : float
            Minimum value.
        max : float
            Maximum value.

    Returns
    -------
        :obj:`str`

    """

    return '{:<.3} |-- {:^8.3} --| {:<9.3}'.format(min, max - min, max)