on ?tag)</code> </td> <td> Captures the current index into the text and advances no input. </td></tr>
    <tr><td><code class="mendoza-code">($ ?tag)</code> </td> <td> Alias for <code class="mendoza-code">(position ?tag)</code>. </td></tr>
    <tr><td><code class="mendoza-code">(accumulate patt ?tag)</code> </td> <td> Capture a string that is the concatenation of all captures in patt. This will try to be efficient and not create intermediate strings if possible. </td></tr>
    <tr><td><code class="mendoza-c