nfa_graph__mark_epsilon_transition Subroutine

   pure recursive subroutine nfa_graph__mark_epsilon_transition(self, state_set, idx)
      use :: forgex_segment_m, only: operator(==)
      implicit none
      class(nfa_graph_t), intent(in) :: self
      type(nfa_state_set_t), intent(inout) :: state_set
      integer, intent(in) :: idx

      integer :: j, dst

      call add_nfa_state(state_set, idx)

      if (.not. allocated(self%graph(idx)%forward)) return

      do j = 1, self%graph(idx)%forward_top

         dst = self%graph(idx)%forward(j)%dst

         if (dst == NFA_NULL_TRANSITION) cycle

         if (self%graph(idx)%forward(j)%c%is_flagged_epsilon() .and. &
            .not. check_nfa_state(state_set, dst)) then

            if (dst /= NFA_NULL_TRANSITION) then
                call self%mark_epsilon_transition(state_set, dst)
            end if
            
         end if
      end do

   end subroutine nfa_graph__mark_epsilon_transition