samer@0: function u=construct(s,sizes_in)
samer@0: 	nin=nargin(s.base);
samer@0: 	nout=nargout(s.base);
samer@0: 
samer@0: 	running=0;
samer@0: 	current_arrow = s.base;
samer@0: 	current_unit  = construct(current_arrow,sizes_in(1:nin));
samer@0: 	current_proc  = current_unit.process;
samer@0: 
samer@0: 	u=mkunit(s);
samer@0: 	u.sizes_out = current_unit.sizes_out;
samer@0: 	u.starting = @starting;
samer@0: 	u.stopping = @stopping;
samer@0: 	u.dispose  = @dispose;
samer@0: 	u.get_state = @get_state;
samer@0: 	u.set_state = @set_state;
samer@0: 
samer@0: 	if     nin==1 && nout==1, u.process=@proc_11;
samer@0: 	elseif nin==1 && nout==0, u.process=@proc_10; 
samer@0: 	elseif nin==0 && nout==1, u.process=@proc_01; 
samer@0: 	else,  u.process=@proc_nn; end
samer@0: 
samer@0: 	function starting, current_unit.starting(); running=1; end
samer@0: 	function stopping, current_unit.stopping(); running=0; end
samer@0: 	function dispose,  current_unit.dispose(); end
samer@0: 
samer@0: 	function s=get_state,  s={current_arrow, current_unit.get_state()}; end
samer@0: 	function set_state(s), replace_running_unit(s{1},s{2}); end
samer@0: 		
samer@0: 	function y1=proc_11(x1,x), 
samer@0: 		if ~isempty(x), replace_running_unit(x{1}); end
samer@0: 		y1=current_proc(x1); 
samer@0: 	end
samer@0: 
samer@0: 	function x=proc_10(x1,x), 
samer@0: 		if ~isempty(x), replace_running_unit(x{1}); end
samer@0: 		current_proc(x1); 
samer@0: 	end
samer@0: 	function y1=proc_01(x),
samer@0: 		if ~isempty(x), replace_running_unit(x{1}); end
samer@0: 		y1=current_proc(); 
samer@0: 	end
samer@0: 
samer@0: 	function varargout=proc_nn(varargin)
samer@0: 		x=varargin{end};
samer@0: 		if ~isempty(x), replace_running_unit(x{1}); end
samer@0: 		[varargout{1:nout}]=current_proc(varargin{1:nin});
samer@0: 	end
samer@0: 
samer@0: 	function replace_running_unit(a,state)
samer@0: 		if running 
samer@0: 			current_unit.stopping(); 
samer@0: 			current_unit.dispose(); 
samer@0: 		end
samer@0: 		current_arrow=a;
samer@0: 		current_unit=construct(a,sizes_in(1:nin));
samer@0: 		current_proc=current_unit.process;
samer@0: 		if nargin>1, current_unit.set_state(state); end
samer@0: 		if running, current_unit.starting(); end
samer@0: 	end
samer@0: end
samer@0: 
samer@0: