title: What kind of Ruby / Erb is allowed inside HAML's :javascript filter?
body: <p>It seems that inside of HAML's <code>:javascript</code> filter, no Ruby code is
  allowed, not even a comment.</p>
  
  <p>So this is NOT allowed:</p>
  
  <pre><code>:javascript
    - 1.upto(10) do |i|
  
  :javascript
    -# just a comment not to show to public
  </code></pre>
  
  <p>(somebody said there is not way to hide comment like that inside a
  <code>:javascript</code> filter.  Is that true?</p>
  
  <p>but it seems the only thing allowed is</p>
  
  <pre><code>:javascript
    $('#aDiv').html('#{a_ruby_variable}');
  </code></pre>
  
  <p>only this #{ } is allowed.  Nothing else that is Ruby is allowed?</p>