Potential Filter Pattern for RXQ

filter.xqy

xquery version "1.0-ml";

import module namespace functx = "http://www.functx.com" at
  "/MarkLogic/functx/functx-1.0-nodoc-2007-01.xqy";

declare option xdmp:mapping "false";

declare variable $filters-sequence as function(*)* :=
  fn:function-lookup(xs:QName("local:upper-case"), 1),
  fn:function-lookup(xs:QName("local:reverse"), 1),
  fn:function-lookup(xs:QName("local:add-english-northerner"), 1);

declare function local:apply-filters($content, $filters as function(*)*)
{
  if(fn:exists($filters)) then
    local:apply-filters(
      $filters[1]($content),
      $filters[2 to fn:last()]
    )
  else $content
};

declare function local:upper-case($content) {
  fn:upper-case($content)
};

declare function local:reverse($content) {
  functx:reverse-string($content)
};

declare function local:add-english-northerner($content) {
  "eyy oop " || $content
};



local:apply-filters("John Smith", $filters-sequence)