client.java

《Java与模式》一书的源代码

package com.javapatterns.interpreter;

public class Client
{
    private static Context ctx;
    private static Expression exp;

    public static void main(String[] args)
    {
        ctx = new Context();

        Variable x = new Variable("x");
        Variable y = new Variable("y");
        Constant c = new Constant(true);

        ctx.assign(x, false);
        ctx.assign(y, true);

        exp = new Or(new And(c, x), new And(y, new Not(x)));
        System.out.println("x = " + x.interpret(ctx));
        System.out.println("y = " + y.interpret(ctx));
        System.out.println(exp.toString() + " = " + exp.interpret(ctx));
    }
}