如何在基于PHP的Perl兼容正则表达式中匹配相邻的分隔符对？

I have a string which could contain multiple delimiters right next to each other, for example |||, although it could be any number of adjacent delimiters. I need to replace any place "in between" the adjacent pair with a specific character. These delimiters will only need to match if there is no character between the delimiter, not even spaces.I have a string which could contain multiple de