Options in the sample compiler

@c+	listcode
@a+	show parser actions
@p+	show parse stack repeatedly
@t+	show tokens when recognized
@o+	turn optimized code generation on
@d+	show the semantic stack once
@s+	dump the symbol table once
@m+	show messages

In the skeleton compiler you have only c, o, s, and m.
Option o does nothing in the skeleton compiler. It generates 
different code in the sample compiler. 

(The skeleton compiler also has option r to give a report
of allocated registers. This is not available in the sample
compiler.)

These may be combined (only in sample compiler) as in 
@c+t+. In your compiler you must give @ for each option.

They are turned off using a - rather than a +

@c-t-

Therefore they may be used to document 
a portion of a program

For all listings turned in to the instructor,
you should use @c+ and only @c+. 

Note that the sample compiler runner.exe requires
the file tables to be in the same directory. It reads
from standard input and writes its listing to
standard output, so you usually run it with:
runner <test0 >list0
 