nfa__add_transition Subroutine

   pure subroutine nfa__add_transition (self, src, dst, seg)
      implicit none
      class(nfa_state_node_t), intent(inout) :: self
      integer(int32), intent(in) :: src, dst
      type(segment_t), intent(in) :: seg(:)

      integer :: j, k

      j = NFA_NULL_TRANSITION
      if (allocated(self%forward)) then
         do k = 1, self%forward_top
            if (dst == self%forward(k)%dst) then
               j = k
            end if
         end do
      end if
      
      if (j == NFA_NULL_TRANSITION) then
         j = self%forward_top
      end if

      if (.not. allocated(self%forward)) then
         call self%realloc_forward()
      end if

      if (any(seg == SEG_EPSILON)) then
         call self%forward(j)%c%flag_epsilon()
      else
         call self%forward(j)%c%add(seg)
      end if

      self%forward(j)%dst = dst
      self%forward(j)%is_registered = .true.

      if (j == self%forward_top) self%forward_top = self%forward_top + 1

   end subroutine nfa__add_transition