Interpreter (Chapter 25)

SOLUTION 25.1The following program will shut down all the machines that MachineLine controls, except for the unload buffer: 
package com.oozinoz.robot.interpreter;
import com.oozinoz.machine.*;
public class ShowIf
{
    public static void main(String[] args)
    {
        Context c = MachineLine.createContext();
        Variable m = new Variable("m");
        Constant ub =
            new Constant(c.lookup("UnloadBuffer1501"));
        Term t = new Equals(m, ub);
        
        IfCommand ic =
            new IfCommand(
                t,
                new NullCommand(),
                new ShutdownCommand(m));
        ForMachines fc = new ForMachines(m, ic);
        fc.execute(c);
    }
}

The fc object is an interpreter; it interprets execute() to mean shut down all machines except the unload buffer.

SOLUTION 25.2One solution is: 
 package com.oozinoz.robot.interpreter; ...

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