add interpreter DP

Liu Yuning · Liu Yuning · commit 7dd62b2d2317 · 2017-05-21T23:11:01.000+08:00
diff --git a/src/designpattern/interpreter/AbstractExpression.java b/src/designpattern/interpreter/AbstractExpression.java
@@ -0,0 +1,12 @@
+package designpattern.interpreter;
+
+/**
+ * 声明一个抽象的解释操作，这个接口为抽象语法树中所有的节点所共享
+ * 
+ * @author liu yuning
+ *
+ */
+public abstract class AbstractExpression {
+
+    public abstract void interpret(Context context);
+}
diff --git a/src/designpattern/interpreter/Context.java b/src/designpattern/interpreter/Context.java
@@ -0,0 +1,30 @@
+package designpattern.interpreter;
+
+/**
+ * 包含解释器之外的一些全局信息
+ * 
+ * @author liu yuning
+ *
+ */
+public class Context {
+
+    private String input;
+    private String output;
+
+    public String getInput() {
+	return input;
+    }
+
+    public void setInput(String input) {
+	this.input = input;
+    }
+
+    public String getOutput() {
+	return output;
+    }
+
+    public void setOutput(String output) {
+	this.output = output;
+    }
+
+}
diff --git a/src/designpattern/interpreter/InterpreterClient.java b/src/designpattern/interpreter/InterpreterClient.java
@@ -0,0 +1,28 @@
+package designpattern.interpreter;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * 构建表示该文法定义的语言中一个特定的句子的抽象语法树，调用解释操作
+ * 
+ * @author liu yuning
+ *
+ */
+public class InterpreterClient {
+    public static void main(String[] args) {
+	Context context = new Context();
+	List<AbstractExpression> list = new ArrayList<AbstractExpression>();
+
+	list.add(new TerminalExpression());
+	list.add(new NonTerminalExpression());
+	list.add(new TerminalExpression());
+	list.add(new TerminalExpression());
+
+	for (AbstractExpression expression : list) {
+	    expression.interpret(context);
+	}
+
+    }
+
+}
diff --git a/src/designpattern/interpreter/NonTerminalExpression.java b/src/designpattern/interpreter/NonTerminalExpression.java
@@ -0,0 +1,16 @@
+package designpattern.interpreter;
+
+/**
+ * 非终结符表达式，为文法中的非终结符实现解释操作。对文法中每一条规则R1、R2 ... ... Rn都需要一个具体的非终结符表达式类。
+ * 
+ * @author liu yuning
+ *
+ */
+public class NonTerminalExpression extends AbstractExpression {
+
+    @Override
+    public void interpret(Context context) {
+	System.out.println("非终端解释器");
+    }
+
+}
diff --git a/src/designpattern/interpreter/TerminalExpression.java b/src/designpattern/interpreter/TerminalExpression.java
@@ -0,0 +1,17 @@
+package designpattern.interpreter;
+
+/**
+ * 实现与文法中的终结符相关联的解释操作，文法中每一个终结符都有一个具体终结表达式与之相对应
+ * 
+ * @author liu yuning
+ *
+ */
+public class TerminalExpression extends AbstractExpression {
+
+    @Override
+    public void interpret(Context context) {
+	System.out.println("终端解释器");
+
+    }
+
+}
