xquery version "1.0";

module namespace functx = "http://www.functx.com"; 

declare function functx:substring-before-last( $arg as xs:string?, $delim as xs:string ) as xs:string {
  if (matches($arg, functx:escape-for-regex($delim)))
  then replace($arg,
           concat('^(.*)', functx:escape-for-regex($delim),'.*'),
           '$1')
  else ''
};

declare function functx:substring-after-last( $arg as xs:string?, $delim as xs:string ) as xs:string {
  replace ($arg,concat('^.*',functx:escape-for-regex($delim)),'')
};

declare function functx:escape-for-regex( $arg as xs:string? ) as xs:string {
  replace($arg,
           '(\.|\[|\]|\\|\||\-|\^|\$|\?|\*|\+|\{|\}|\(|\))','\\$1')
};