Behavior or Re.Pcre.split when only separators are found

[elboulangero]

I observe this behavior (Debian Sid, re 1.11.0):

utop # let whitespace_re = Re.Pcre.regexp "\\s+";;
val whitespace_re : Re.re = <abstr>

utop # Re.Pcre.split ~rex:whitespace_re ("");;
- : string list = []

utop # Re.Pcre.split ~rex:whitespace_re (" ");;
- : string list = [""]

Is it the expected behavior? In the second case I would have expected [] instead of [""].

For comparison, here's what I get with the pcre library:

utop # Pcre.split ("");;
- : string list = []

utop # Pcre.split ("  ");;
- : string list = []

Thanks