解释器模式 InterpretePattern

文法树抽象

using System; public abstract class Interpretor { private string _Expression; public Interpretor(string expression) { _Expression = expression; } public string Expression { get { return _Expression; } } public abstract string Transfer(); }

文法树实例A

using System; public class FruitInterpretor : Interpretor { public FruitInterpretor(string expression):base(expression) { } public override string Transfer() { string result; switch (Expression) { case "fo": result = "橘子"; break; case "fa": result = "苹果"; break; case "fb": result = "香蕉"; break; default: result = "未知的水果"; break; } return result; } }

解释内容

using System; public class InterpreteContext { private string _InputContext; private string _OutputContext; public InterpreteContext(string context) { _InputContext = context; } public string InputContext { get { return _InputContext; } } public string OutputContext { get { return _OutputContext; } set { _OutputContext = value; } } }

调用代码

using System; using System.Collections.Specialized; using System.Collections.Generic; using System.Text; namespace InterpretePattern { class Program { static void Main(string[] args) { //使用堆栈来做 int offset=0; Stack<string> words=new Stack<string>(); InterpreteContext context = new InterpreteContext("i like fo fb and fa "); FruitInterpretor interpetor; for (int i = 0; i < context.InputContext.Length; i++) { switch (context.InputContext[i]) { case ' ': words.Push(context.InputContext.Substring(offset,i-offset)); offset=i+1; break; default: break; } } foreach (string express in words) { if (express.Length == 2 && express.StartsWith("f")) { interpetor = new FruitInterpretor(express); context.OutputContext = interpetor.Transfer() + " " + context.OutputContext; } else context.OutputContext = express + " " + context.OutputContext; } //string result = words.ToString(); Console.WriteLine(context.OutputContext); Console.ReadKey(); } } }

执行结果：

i like 橘子 香蕉 and 苹果