title: Use Freemarker macro call within string parameter of another macro
body: <p>I have a macro A that formats some text
  <code>&lt;#macro A text&gt;...${text}...&lt;/#macro&gt;</code>
  and another macro that has a parameter accepting text
  <code>&lt;#macro B x&gt;Another ${x} text&lt;/#macro&gt;</code></p>
  
  <p>I'd like to call B with the x paramter to be some text formatted by A, s.th. like
  <code>&lt;@B x="&lt;@A text='abc'/&gt;" /&gt;</code> returns <code>Another &lt;@A text='abc'/&gt;</code></p>
  
  <p>Is this possible somehow?</p>
  
  <p>I tried the <code>?interpret</code> as <a href="https://stackoverflow.com/a/8369688/1480587">suggested here by ddekany</a> - 
  <code>&lt;@B x="&lt;@A text='abc'/&gt;"?interpret /&gt;</code> but this fails with the error:</p>
  
  <blockquote>
    <p>Expecting a string, date or number here, Expression .... is
    instead a freemarker.core.Interpret$TemplateProcessorModel</p>
  </blockquote>
  
  <p>It seems that a macro call in FreeMarker is something different than a function call in other languages.</p>