Stacks and compilers - Data Structures and Problem Solving Using Java - page 455

1 // main routine for balanced symbol checker.
2 // If no command line parameters, standard output is used.
3 // Otherwise, files in command line are used.
4 public static void main( String [ ] args )
5 {
6 Balance p;
7
8 if( args.length == 0 )
9 {
10
11 p = new Balance( new InputStreamReader( System.in ) );
12 if( p.checkBalance( ) == 0 )
13 System.out.println( "No errors!" );
14 return;
15 }
16
17 for( int i = 0; i < args.length; i++ )
18 {
19 FileReader f = null;
20 try
21 {
22 f = new FileReader( args[ i ] );
23
24 System.out.println( args[ i ] + ": " );
25 p = new Balance( f );
26 if( p.checkBalance( ) == 0 )
27 System.out.println( " ...no errors!" );
28 }
29 catch( IOException e )
30 { System.err.println( e + args[ i ] ); }
31 finally
32 {
33 try
34 { if( f != null ) f.close( ); }
35 catch( IOException e )
36 { }
37 }
38 }
39 }

figure 11.10
The main routine with
command-line
arguments

1 - 2 - 4 ^ 5 * 3 * 6 / 7 ^ 2 ^ 2

would be quite challenging.
If the calculations are performed in integer math (i.e., rounding down on
division), the answer is -8 . To show this result, we insert parentheses to clarify
ordering of the calculations:

( 1 - 2 ) - ( ( ( ( 4 ^ 5 ) * 3 ) * 6 ) / ( 7 ^ ( 2 ^ 2 ) ) )