hashtbl_obj_Init Subroutine

    pure subroutine hashtbl_obj_Init(this,tbl_len)
      !> Initializes the hashtable.
      implicit none
      class(hashtbl_obj),    intent(inout) :: this                             !! Hashtable object
      integer,               intent(in)    :: tbl_len                          !! Hashtable vector length

      if (allocated(this%vec)) deallocate(this%vec)
      allocate(this%vec(tbl_len))
      this%vec_len = tbl_len

      return
    end subroutine hashtbl_obj_Init