fier">phrase_parse</span></code>
          function, used, and then destroyed. This is fine for small parsers. When
          the expressions get complicated, you'd want to break the expressions into
          smaller easier-to-understand pieces, name them, and refer to them from
          other parser expressions by name.
        </p>
<p>
          A parser expression can be assigned to what is called a "rule".
          There are various ways to declare rules. The simplest form is:
        </p>
<pre class