title: Unclosed GSP expression: Grails GSP engine does not resolve nested GSP expression
body: <p>I need to create a custom gsp whose domain model is designed as follows</p>
  
  <pre><code>class Question {
  
      SortedSet&lt;Choice&gt; choiceCollection;
  
      static hasMany = [choiceCollection:Choice]
      static mappping = {
          choiceCollection(joinTable:false)
      }
  
  }
  </code></pre>
  
  <p>Each Question object has five Choices. So, i create the following snippet of code</p>
  
  <p><strong>create.gsp</strong></p>
  
  <pre><code>&lt;g:each var="i" in="${(1..5)}"&gt;
      &lt;div class="fieldcontain  required"&gt;
      &lt;label for="description"&gt;
              Option ${i}.
              &lt;span class="required-indicator"&gt;*&lt;/span&gt;
          &lt;/label&gt;
          &lt;g:textArea name="choiceCollection[${i}].description" cols="40" rows="5" maxlength="2000" value="${questionInstance?.choiceCollection[${i}]?.description}"/&gt;
      &lt;/div&gt;
  &lt;/g:each&gt;
  </code></pre>
  
  <p>Although Grails GSP engine complains <em>Unclosed GSP expression</em> which is not true - g:textArea is closed as you can see above -, i believe the real problem is the expression</p>
  
  <pre><code>${questionInstance?.choiceCollection[${i}]?.description}
  </code></pre>
  
  <p>which involves nested GSP expressions. </p>
  
  <p>Question: am i missing some feature ? If so, what should i do to overcome my obstacle ?</p>
  
  <p>Grails version: 2.1.1</p>