not perform 
any semantic actions &amp;emdash; it will only indicate success or failure of a parse.
To calculate and print values of each expression, we must embed Java
code within the parser to carry out actions at various points.  In CUP,
actions are contained in <i>code strings</i> which are surrounded by delimiters 
of the form <tt>{:</tt> and <tt>:}</tt> (we can see examples of this in the 
<tt>init with</tt> and <tt>scan with</tt> clauses above).  In general, the 
system records all characters within 