function save_except(varargin)
%SAVE_EXCEPT Save current workspace to disk except variables stated
%
% Like SAVE, this command can be called using statement syntax
%     save_except filename var1 var2 ...
%     save_except filename -option1 var1 var2 ... -option2
%
% ...or function syntax:
%     save_except('filename', 'var1', 'var2', ...)
%     save_except('filename', 'var1', 'var2', ..., '-option1', '-option2')
%
% All variables in the calling workspace *except* those specified will be saved
% to disk.
%
% Options accepted by Matlab's save can be passed in any position, except
% -regexp and -struct, which are not supported. Wildcards in the variable names
% are also not supported.
%
% If the variables to exclude don't exist, this is silently ignored.
% To force an error, pass the '-PEDANTIC' option.

% Iain Murray, March 2009

if ~all(cellfun(@isstr, varargin))
    error('All arguments must be strings');
end

% Extract and separate arguments
opts = {};
exclude_vars = {};
filename = '';
for arg_cell = varargin
    arg = arg_cell{:};
    if arg(1) == '-'
        opts{end + 1} = arg;
    else
        if filename
            if ismember('*', arg)
                error('* wildcards are not supported');
            end
            exclude_vars{end + 1} = arg;
        else
            filename = arg;
        end
    end
end

% Process options
opts = lower(opts);
if ismember('-regexp', opts)
    error('-regexp option not supported');
end
if ismember('-struct', opts)
    error('-struct option not supported');
end
pedantic = ismember('-pedantic', opts);
opts = setdiff(opts, '-pedantic');

% Work out which variables to save
ws = evalin('caller', 'whos');
all_vars = {ws.name};
if pedantic
    bad = exclude_vars(~ismember(exclude_vars, all_vars));
    if length(bad) > 0
        error(['Some variables to exclude do not exist: ', sprintf('%s, ', bad{:})]);
    end
end
vars = setdiff(all_vars, exclude_vars);

% Drive Matlab's save command
save_cmd = ['save(', argstr(filename, opts{:}, vars{:}), ')'];
if isempty(vars)
    save_empty();
else
    evalin('caller', save_cmd);
end



function str = argstr(varargin)
%ARGSTR convert string arguments into a single string for eval
str = '';
if length(varargin) > 0
    for a_cell = varargin
        str = [str 39 a_cell{:} 39 ', '];
    end
    str = str(1:end-2);
end


function save_empty()
% This function covers the corner case when all variables are excluded.
% Do the same as Matlab's save when run on an empty workspace.
eval(evalin('caller', 'save_cmd'));