update_object_depth Subroutine

  subroutine update_object_depth(line, object_depth)
    !! Update a nested object depth counter from one JSON line.
    implicit none

    ! Arguments
    character(*), intent(in) :: line
    !! Current JSON line
    integer, intent(inout) :: object_depth
    !! Mutable object depth counter

    ! Local variables
    integer :: i
    !! Character index while scanning braces

    do i = 1, len_trim(line)
       if(line(i:i) .eq. '{') object_depth = object_depth + 1
       if(line(i:i) .eq. '}') object_depth = object_depth - 1
    end do

  end subroutine update_object_depth