isrealvarname.m

function retval = isrealvarname(testname)
% isrealvarname  - true for valid variable name
%
% FORMAT:       rv = isrealvarname(testname)
%
% Input fields:
%
%       testname    string tested for being a variable name
%
% Output fields:
%
%       rv          flag whether testname is a suitable var name
%
% Note: revised, since older Windows versions falsely return true

% Version:  v0.9a
% Build:    10051716
% Date:     May-17 2010, 10:48 AM EST
% Author:   Jochen Weber, SCAN Unit, Columbia University, NYC, NY, USA
% URL/Info: http://neuroelf.net/

% Copyright (c) 2010, Jochen Weber
% All rights reserved.
%
% Redistribution and use in source and binary forms, with or without
% modification, are permitted provided that the following conditions are met:
%     * Redistributions of source code must retain the above copyright
%       notice, this list of conditions and the following disclaimer.
%     * Redistributions in binary form must reproduce the above copyright
%       notice, this list of conditions and the following disclaimer in the
%       documentation and/or other materials provided with the distribution.
%     * Neither the name of Columbia University nor the
%       names of its contributors may be used to endorse or promote products
%       derived from this software without specific prior written permission.
%
% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
% ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
% WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
% DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
% DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
% (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
% LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
% ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
% (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
% SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

% argument check
if nargin < 1
    error( ...
        'neuroelf:TooFewArguments',...
        'Too few arguments.'...
    );
end

% test only valid char inputs
if ischar(testname) && ...
   ~isempty(testname) && ...
    numel(testname) == size(testname, 2) && ...
    all(double(testname) < 123 & double(testname) > 47) && ...
    testname(1) > 64 && ...
   (testname(1) < 91 || ...
    testname(1) > 96) && ...
   ~any(any(double(testname(ones(12, 1), :)) == (([58:64, 91:94, 96])' * ones(1, numel(testname)))))
    retval = true;
else
    retval = false;
end