Functx 模块和以字符结尾的长字符串

Question

我遇到了 functx 模块处理带有行尾字符的字符串的问题。以下代码应该有效 (?)

declare %unit:test function test:substring-before-last() {

  let $title := 'Something
blah other'

  let $expected-title := 'Something
blah'

  return unit:assert-equals(functx:substring-before-last($title, ' other'),
    $expected-title)
};

但是它失败了

"Something
blah" expected, "Something
blah other" returned.

删除换行符使测试正常进行。我不明白什么？ :)

BR

Answer 1

我认为问题出在 functx 函数的定义或实现上 http://www.xqueryfunctions.com/xq/functx_substring-before-last.html:

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),'.*'),
            '')
   else ''
 } ;

和正则表达式点.匹配和replace默认“如果输入字符串不包含与正则表达式匹配的子字符串，函数的结果是与输入字符串。";如果您添加标志 m 参数

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),'.*'),
            '', 'm')
   else ''
 } ;

你得到了正确的匹配、替换和比较。

Functx 模块和以字符结尾的长字符串

Functx module and long strings with end of chars

xquery

basex

xquery-3.1