使用 xquery 进行字符串连接

Question

我们需要将十六进制转换为二进制。经过很好的研究，我们能够实现它，但问题是输出在每组二进制元素之间都有空格。

如何去除这些空格？

以下代码给出的输出为： 0111 0110 0010 0100

必填： 0111011000100100

---

xquery version "1.0" encoding "utf-8"
(:: OracleAnnotationVersion "1.0" ::)
declare namespace ns1="http://www.s2mpos.com/v1";
(:: import schema at "s2miso8583.xsd" ::)
declare namespace bin="http://expath.org/spec/binary";
declare variable $ReadLine as xs:string external;
declare function local:charsReturn($arg as xs:string) as xs:string*
{
  for $ch in string-to-codepoints($arg)
  return codepoints-to-string($ch)
};

declare function local:convertString($argx as xs:string) as xs:string*
{ 
  let $x := local:charsReturn($ReadLine)
       for $a in $x
       return
         string-join(
          for $b in (8,4,2,1)
          let $cv := xs:integer($a)
          let $xm := $cv mod ($b*2)
          return
            if ( $xm >= $b ) then "1" else "0"
        ,"")
};

declare function local:func($ReadLine as xs:string) as element() (:: schema-element(ns1:s2mMessages) ::) {
  <ns1:s2mMessages>
    {
      let $abc := local:convertString($ReadLine)
    } 
  </ns1:s2mMessages>
};

local:func($ReadLine)

Answer 1

我看不出您的代码是如何工作的。如果$Readline 包含十六进制数字，则$a 可以是任何十六进制数字，例如“C”，如果$a 是“C”，则xs:integer($a) 将失败并显示FORG0001。

我愿意：

string-join(
  let $hex := ('0', '1', '2', '3', ... 'E', 'F')
  let $bin := ('0001', '0010', '0011', '0100', ...., '1110', '1111')
  for $a in local:charsReturn($ReadLine)
  return $bin[index-of($hex, $a)], "")