p:xquery 031 (AB)

The pipeline

<p:declare-step xmlns:err="http://www.w3.org/ns/xproc-error" xmlns:p="http://www.w3.org/ns/xproc" version="3.0">
   <p:output port="result"/>
   <p:xquery version="3.0" parameters="map{'var' : map{'key' : 'value'}}">
      <p:with-input port="source">
         <p:empty/>
      </p:with-input>
      <p:with-input port="query">
         <p:inline content-type="text/plain">
                  declare namespace map="http://www.w3.org/2005/xpath-functions/map";
                  declare variable $var external;
                  &lt;result&gt;{{map:get($var, 'key')}}&lt;/result&gt;
               </p:inline>
      </p:with-input>
   </p:xquery>
</p:declare-step>