 high level
        overview of how the <span class="emphasis"><em>Spirit.Lex</em></span> library might be used
        in an application. <span class="emphasis"><em>Spirit.Lex</em></span> allows to create lexical
        analyzers based on patterns. These patterns are regular expression based
        rules used to define the different tokens to be recognized in the character
        input sequence. The input sequence is expected to be provided to the lexical
        analyzer as an arbitrary standard forwar