samer@0: % sink - Base class for sink
samer@0: %
samer@0: % sink :: sink(C:natural,R:nonneg).
samer@0: %
samer@0: % The sink(C,R) type denotes the type of a sink with C
samer@0: % channels and a sampling rate of R. 
samer@0: %
samer@0: % The base sink class cannot be used without subclassing since
samer@0: % any attempt to instantiate the live sink will throw
samer@0: % an exception.
samer@0: %
samer@0: % METHODS
samer@0: %    channels :: sink(C,R) -> natural.
samer@0: %    rate     :: sink(C,R) -> nonneg. 
samer@0: %    construct:: sink(C,R) -> livesink(C,_).
samer@0: %    capacity :: sink(C,R) -> natural.
samer@0: %
samer@0: % livesink(C,Z) :== struct {
samer@0: %    start   :: void->void;
samer@0: %    stop    :: void->void;
samer@0: %    dispose :: void->Z;
samer@0: %    writer  :: N:natural -> ([[C,N]] -> natural);
samer@0: % }
samer@0: 
samer@0: classdef sink
samer@0: 	methods
samer@0: 		function o=sink, end
samer@0: 		function s=and(s1,s2), s=sinkcat(s1,s2); end
samer@0: 		function r=rate(s), error('sampling rate undefined'); end
samer@0: 		function c=channels(s), error('number of channels undefined'); end
samer@0: 		function s=construct(sig), error('Cannot construct base sink class'); end
samer@0: 
samer@0: 		function display(a)
samer@0: 			disp(sprintf('    %s :: sink(%s,%s)',tostring(a),fmt(channels(a)),fmt(rate(a))));
samer@0: 			function s=fmt(x), if isnan(x), s='_'; else s=num2str(x); end; end
samer@0: 		end
samer@0: 
samer@0: 		function y=map(f,chf,x), y=sinkmap(f,chf,x); end
samer@0: 		function y=drop(n,x), y=sinkdrop(n,x); end
samer@0: 		function y=take(n,x), y=sinktake(n,x); end
samer@0: 		function y=dropt(t,x), 
samer@0: 			if isnan(rate(x)), error('Cannot dropt without definite sampling rate'); end
samer@0: 			y=sinkdropt(round(t*rate(x)),x);
samer@0: 		end
samer@0: 
samer@0: 		function y=taket(t,x), 
samer@0: 			if isnan(rate(x)), error('Cannot taket without definite sampling rate'); end
samer@0: 			y=sinktake(round(t*rate(x)),x);
samer@0: 		end
samer@0: 	end
samer@0: end