gettok: a pedestrian matlab constructs decoder

recursively decodes MATLAB constructs such as numbers, strings, structures, cells, and returns
- <eval>uable MATLAB constructor syntax
- a descriptive summary of the constructor's contents
- the contents itself

and - for historical reasons
- converts strings to and from cells
- creates character ranges

the convenient GETTOK wrapper STOK creates two panels

the upper panel lists the constructor syntax and contents descriptor of each entry
- selecting line 1 will display a brief help in the lower panel
- selecting line 2 will display a version summary in the lower panel
- selecting an entry displays a summary and the contents of the constructor in the lower panel
- selecting any item in the lower panel displays the constructor syntax in the command window for copy/paste operations
- evaluating a constructor at the command prompt will return its contents

see the accompanying published M-file for an example