m{
    \A    # anchor to start
    (\W)  # open text
    (?: (?!\1) . )*  # anything that isn't the closer
    \1    # close text
    (\W)  # separator
  }xs

##</code><code>##

  m{
    \A    # anchor to start
    (\W)  # open text
    .*?   # anything contained, up to the ...
    \1    # ... close text
    (\W)  # separator
  }xs