 whether or not to allow &lsquo;\&rsquo; as an escape character; and <em>balanced</em> indicates
    whether or not to handle balanced ranges like parentheses, and requires <em>s</em>
    and <em>e</em> to be different.</p>

    <p>Parameters:</p>

    <ul>
    <li><em><code>s</code></em>: String or pattern start of a range.</li>
    <li><em><code>e</code></em>: Optional string or pattern end of a range. The default value is <em>s</em>.</li>
    <li><em><code>single_line</code></em>: Optional flag indicatin