xer_quickstart1.html#spirit.lex.tutorials.lexer_quickstart1.defining_tokens">Defining
          Tokens</a>
        </h6>
<p>
          The most important step while creating a lexer using <span class="emphasis"><em>Spirit.Lex</em></span>
          is to define the tokens to be recognized in the input sequence. This is
          normally done by defining the regular expressions describing the matching
          character sequences, and optionally their corresponding token ids. Additionally
          the defi