samer@0: function u=construct(s,sizes_in)
samer@0: 
samer@0: 	nin=nargin(s.base);
samer@0: 
samer@0: 	u=construct(s.base,s.sizes_in(1:nin));
samer@0: 	u.sizes_out = [u.sizes_out]; % !!! this is wrong. need better type system
samer@0: 	u.process = mkproc(u.process,nin,nargout(s.base));
samer@0: end
samer@0: 
samer@0: function f=mkproc(g,nin,nout)
samer@0: 	empty={{}};
samer@0: 	f=@proc;
samer@0: 	if nin==1 && nout==1, f=@proc_11;
samer@0: 	elseif nin==1 && nout==0, f=@proc_10; 
samer@0: 	else, f=@proc_nn; end
samer@0: 
samer@0: 	function proc_10(x1), 
samer@0: 		if ~isempty(x1), g(x1{1}); end; 
samer@0: 	end
samer@0: 	function y1=proc_11(x1,x), if isempty(x1), y1={}; else y1={g(x1{1})}; end; end
samer@0: 
samer@0: 	function varargout=proc_nn(varargin)
samer@0: 		if any(cellfun(@isempty,varargin)), varargout=repmat(empty,1,nout);
samer@0: 		else
samer@0: 			ins=cellfun(@unbox,varargin(1:nin));
samer@0: 			[outs{1:nout}]=g(ins{:});
samer@0: 			varargout=cellfun(@box,outs);
samer@0: 		end
samer@0: 	end
samer@0: 	function x=unbox(y), x=y{1}; end
samer@0: 	function y=box(x), y={x}; end
samer@0: end
samer@0: