nfa_graph__reallocate Subroutine

   pure subroutine nfa_graph__reallocate(self)
      implicit none
      class(nfa_graph_t), intent(inout) :: self
      type(nfa_state_node_t), allocatable :: tmp(:)
      integer :: n

      n = ubound(self%graph, dim=1)
      call move_alloc(self%graph, tmp)

      allocate(self%graph(NFA_STATE_BASE:n*2))
      
      self%graph(NFA_STATE_BASE:n) = tmp(NFA_STATE_BASE:n)

      self%graph(n+1:n*2)%forward_top = 1
   end subroutine nfa_graph__reallocate