exer</code> module API functions</h2>

    <p><a id="lexer.add_fold_point"></a></p>

    <h3><code>lexer.add_fold_point</code>(lexer, token_name, start_symbol, end_symbol)</h3>

    <p>Adds to lexer <em>lexer</em> a fold point whose beginning and end tokens are string
    <em>token_name</em> tokens with string content <em>start_symbol</em> and <em>end_symbol</em>,
    respectively.
    In the event that <em>start_symbol</em> may or may not be a fold point depending on
    context, and that additional proces