xpath删除元素串联中的多余空格

在xpath中,我将处理如下所示的源XML,在这里我要连接每个源XML的子元素 editor 使用空格分隔符创建全名,然后依次用逗号连接生成的全名:

<biblStruct type="book" xml:id="Biller_2011a">
     <monogr>
        <title>Inquisitors and Heretics in Thirteenth-Century Languedoc: Edition and Translation
           of Toulouse Inquisition Depositions, 1273-1282</title>
        <editor>
           <forename>Peter</forename><surname>Biller</surname>
        </editor>
        <editor>
           <forename>Caterina</forename><surname>Bruschi</surname>
        </editor>
        <editor>
           <forename>Shelagh</forename><surname>Sneddon</surname>
        </editor>
        <imprint>
           <pubPlace>
              <settlement>Leiden</settlement>
              <country>NL</country>
           </pubPlace>
           <publisher>Brill</publisher>
           <date type="pub_date">2011</date>
        </imprint>
     </monogr>
  </biblStruct>

当前,使用xpath的xpath(在xquery中)代码如下所示 map 引入分隔符:

let $bibref := $bib//tei:biblStruct[@xml:id="Biller_2011a"]
return   <editors>{
            (for $auth in $bibref//tei:editor
            return normalize-space(string-join($auth//child::text()," ")))!(if (position() > 1) then ', ' else (), .) 
        }</editors>

但这会在逗号前后输出额外的空间:

<editors>Peter Biller ,  Caterina Bruschi ,  Shelagh Sneddon</editors>

相反,我想输出:

<editors>Peter Biller, Caterina Bruschi, Shelagh Sneddon</editors>  

事先谢谢。