utf8_split Subroutine

    subroutine utf8_split(utf8, sep, list)
        class(utf8_string), intent(in), target :: utf8
        character(len=*, kind=c_char), intent(in) :: sep
        type(utf8_string), dimension(:), allocatable, intent(out) :: list
        character(len=:, kind=c_char), pointer :: ptr
        integer :: nsep, l
        integer :: i, e

        nsep = utf8_count(utf8, sep)
        allocate(list(nsep+1))

        if (nsep == 0) then
            allocate(list(1)%str, source=utf8%str)
        else
            l = len(sep)
            e = 1
            ptr => utf8%str(:)
            do i = 1, nsep
                e = index(ptr, sep)
                allocate(list(i)%str, source=ptr(:e-1))
                ptr => ptr(e+l:)
            end do
            allocate(list(nsep+1)%str, source=ptr(:))
        end if

    end subroutine utf8_split