at(h,attrib)

function f = at(h,attrib)
% function f = at(h,attrib)
% 
% Similar to f = @h but creates a function_handle with embedded attributes. 
% 
% h   function_handle or name of function
% f   function_handle 
%
% Example: f = at('fminbnd');
% See also str2fun, @ 

%% Allow at('@cos'), at('cos'), at('cos.m'), at(@cos), even at('@cos.m')
if ischar(h) && h(1)=='@',
    h = h(2:end);
end
if ischar(h) && length(h)>1 && strcmpi(h(end-1:end),'.m'),
    h = h(1:end-2);
end
if ischar(h),
    h = str2func(h);
end
if nargin<2,
   attrib = funattrib(h);
end
f = funlabel(h,attrib);

function attrib = funattrib(h)
% function attrib = funattrib(h)
%
% h        function_handle 
% attrib     cell array of key-value pairs describing function attributes
%
% Infer attributes of a function_handle

fmuse('/argument_passing_util','argin.m','argout.m');

secretCode = prod(double('fun')); % 1312740
attrib = {'-name',func2str(h),'-argin',argin(h),'-argout',argout(h),'-fun',secretCode,...
          '-handle',h,'-attrib',{'-name','-argin','-argout','-fun','-attrib','-handle'}};

function f = funlabel(h,labels)
%function f = funlabel(h,labels)
%
% h         function_handle  
% labels    cell array of key value pairs 
% f         function_handle
%
% Returns handle to a function f which is in every way identical to h
% unless an attribute is requested. For instance f('name')

%% Determine how many output arguments are required
[ignoreMe,locOut] = ismember('-argout',labels(1:2:end-1));
nArgOut = length(labels{2*locOut});
[ignoreMe,locIn] = ismember('-argin',labels(1:2:end-1));
nArgIn = length(labels{2*locIn});

%% Wrap
f = @(varargin) funeval(h,labels,nArgIn,nArgOut,varargin{:});

function [y1,y2,y3,y4,y5,y6,y7,y8,y9,y10,y11,y12] = funeval(h,labels,nArgIn,nArgOut,varargin)
%
% h        function_handle
% labels   cell array of key-value pairs 
% varargin parameters to be passed to f
%
% Similar to feval except when an attribute is requested

%% Short-circuit and return an attribute? 
if length(varargin)==1 && ischar(varargin{1}) && varargin{1}(1)=='-',
    m = length(labels);
    for k=1:2:m-1,
        key = labels{k};
        if strcmpi(key,varargin{1}),
            y1 = labels{k+1};
            return;
        end
    end
end

%% ... or just evaluate
% A little ugly
if length(varargin)<=nArgIn,
   switch nArgOut
       case 0, ;
       case 1, y1 = feval(h,varargin{:});
       case 2, [y1,y2] = feval(h,varargin{:});
       case 3, [y1,y2,y3] = feval(h,varargin{:});
       case 4, [y1,y2,y3,y4] = feval(h,varargin{:});
       case 5, [y1,y2,y3,y4,y5] = feval(h,varargin{:});
       case 6, [y1,y2,y3,y4,y5,y6] = feval(h,varargin{:});
       case 7, [y1,y2,y3,y4,y5,y6,y7] = feval(h,varargin{:});
       case 8, [y1,y2,y3,y4,y5,y6,y7,y8] = feval(h,varargin{:});
       case 9, [y1,y2,y3,y4,y5,y6,y7,y8,y9] = feval(h,varargin{:});
       case 10, [y1,y2,y3,y4,y5,y6,y7,y8,y9,y10] = feval(h,varargin{:});
       case 11, [y1,y2,y3,y4,y5,y6,y7,y8,y9,y10,y11] = feval(h,varargin{:});
       case 12, [y1,y2,y3,y4,y5,y6,y7,y8,y9,y10,y11,y12] = feval(h,varargin{:});
       otherwise
           error('Current implementation of funeval supports at most twelve output arguments');
   end
else
   error(['funeval:supplied too many input arguments.']); 
end