行为型设计模式之解释器模式(Interpreter)

 1 using System;
 2     using System.Collections;
 3 
 4     class Context 
 5     {
 6         
 7     }
 8 
 9     abstract class AbstractExpression 
10     {
11         abstract public void Interpret(Context c);
12     }
13 
14     // class for terminal symbol
15     class TerminalExpression : AbstractExpression
16     {
17         override public void Interpret(Context c)    
18         {
19             
20         }
21     }
22 
23     // class for grammar rule (one per rule needed)
24     class NonterminalExpression : AbstractExpression
25     {
26         override public void Interpret(Context c)    
27         {
28             
29         }    
30     }
31     // to extend grammar, just add other NonterminalExpression classes
32 
33     /// <summary>
34     ///    Summary description for Client.
35     /// </summary>
36     public class Client
37     {
38         public static int Main(string[] args)
39         {
40             Context c = new Context();
41             ArrayList l = new ArrayList(); //really need a tree here!
42 
43             // build up context information 
44             // . . .
45 
46             // Populate abstract syntax tree with data
47             l.Add(new TerminalExpression());
48             l.Add(new NonterminalExpression());
49 
50             // interpret
51             foreach (AbstractExpression exp in l)
52             {
53                 exp.Interpret(c);
54             }
55                     
56             return 0;
57         }
58     }