plusnode.java

Java写的词法/语法分析器。可生成JAVA语言或者是C++的词法和语法分析器。并可产生语法分析树和对该树进行遍历

import antlr.BaseAST;
import antlr.Token;
import antlr.collections.AST;
import java.io.*;

/** A simple node to represent PLUS operation */
public class PLUSNode extends BinaryOperatorAST {
    public PLUSNode(Token tok) {
    }

    /** Compute value of subtree; this is heterogeneous part :) */
    public int value() {
	return left().value() + right().value();
    }

    public String toString() {
	return " +";
    }
    
    public void xmlSerializeRootOpen(Writer out) throws IOException {
	out.write("<PLUS>");
    }
   
    public void xmlSerializeRootClose(Writer out) throws IOException {
	out.write("</PLUS>");
    }
   
    // satisfy abstract methods from BaseAST
    public void initialize(int t, String txt) {
    }
    public void initialize(AST t) {
    }
    public void initialize(Token tok) {
    }
}