samer@27: % thunk(B@typelist(M)) ~ a thunk is something that eventually yields M outputs
samer@4: classdef thunk
samer@4: 	properties (GetAccess=private, SetAccess=immutable)
samer@27: 		head %  ::  (A@typelist(N) -> B | thunk(B))
samer@27: 		args %  ::  A@typelist(N)
samer@4: 	end
samer@4: 	methods
samer@4: 		% thunk - create delayed evaluation
samer@4: 		function f=thunk(h,varargin), f.head=h; f.args=varargin; end
samer@4: 		function s=tostring(f), s=sprintf('%s(%s)',tostring(f.head),commalist(map(@tostring,f.args))); end
samer@4: 		function display(f), display([tostring(f),' :: thunk']); end
samer@4: 
samer@4: 		% fforce - Completely force a thunk, if keep evaluating till not a thunk
samer@4: 		function f=fforce(f), while isa(f,'thunk'), f=force(f); end; end
samer@4: 
samer@4: 		function varargout=force(f), [varargout{1:nargout}] = feval(f.head,f.args{:}); end
samer@4: 
samer@4: 		% SUBSREF - Subscript referencing for FUNC objects
samer@4: 		function varargout=subsref(f,S)
samer@4: 			s=S(1);
samer@4: 			switch s.type
samer@4: 				case '()', [varargout{1:nargout}] = feval(f.head,f.args{:});
samer@4: 			end
samer@4: 		end
samer@4: 	end
samer@4: end
samer@4: 
samer@4: function s=commalist(a)
samer@4: 	if isempty(a), s='';
samer@4: 	elseif length(a)==1, s=a{1};
samer@4: 	else s=[a{1},',',commalist(a(2:end))];
samer@4: 	end
samer@4: end