You are to write a Scheme version of the ExpressionCalculator class that will produce, as closely as possible, the same runtime behavior as the Java code([url removed, login to view] is included for translation). Note that the output of the Scheme code won't look exactly the same, since the standard Scheme output function display uses a slightly different algorithm than the standard Java output function System.out.print.
In the situation of the calculator, a continuation is needed to return to the commands procedure after an error has occurred. Thus, the continuation needs to be a parameter to every parsing procedure, to the match procedure, and to the error procedure [url removed, login to view] name of this continuation is exitproc. Note also how the command procedure becomes the parameter to call-with-current-continuation. Finally, when the continuation procedure exitproc is called, just pass it the empty list as the value it should return, since we don't really care what this value is.
So, as you see, you don't have to write any continuation code yourself, just use the supplied code, making sure to pass exitproc along to every parsing procedure.
As before, the [url removed, login to view] code that you submit should run the scanner and driver code. You may, if you wish, change the skeleton code, as long as your expressionparser continues to run with the scanner and driver. I would reccommend, though, that you the original code intact.
Document all code for easier understanding.
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Scheme programming language, but must know Java to translate.