Java 如何显示ANTLR树GUI

如果您有这样的代码，无论是console还是swing，如何显示ASTGUI？ 我的ANTLR是版本3

CharStream stream = new ANTLRStringStream("program XLSample1 =\n" + 
            "constant one : Integer := 1;\n" + 
            "constant two : Integer := 2;\n" + 
            "var a, b,c : Integer := 42;\n" + 
            "begin\n" + 
            " x:= (12 + 6) - (7 * 41) - x mod y;\n" + 
            " y := 21;\n" + 
            "\n" + 
            "if x < 10 then\n" + 
            "  y :=2;\n" + 
            "  elseif x < 20 then\n" + 
            "  y := 20;\n" + 
            "  else\n" + 
            "  y := 30;\n" + 
            "end if; \n" + 
            "end XLSample1.");
    SampleLexer lexer  = new SampleLexer(stream);   
    TokenStream tokenStream = new CommonTokenStream(lexer);
    SampleParser parser = new SampleParser(tokenStream);
    parser.program();       
    System.out.println("OK");       
}

CharStream-stream=new-ANTLRStringStream（“程序XLSample1=\n”+
“常数一：整数：=1；\n”+
“常数二：整数：=2；\n”+
变量a、b、c:整数：=42；\n“+
“开始\n”+
“x:=（12+6）-（7*41）-x模y；\n”+
“y:=21；\n”+
“\n”+
“如果x<10，则\n”+
“y:=2；\n”+
“elseif x<20那么\n”+
“y:=20；\n”+
“else\n”+
“y:=30；\n”+
“如果结束；\n”+
“结束样本1”）；
SampleLexer lexer=新的SampleLexer（流）；
TokenStream TokenStream=新的CommonTokenStream（lexer）；
SampleParser=新的SampleParser（令牌流）；
parser.program（）；
System.out.println（“OK”）；
}

使用ANTLR V4（对于V3，请尝试找出类似的API），要显示gui AST，可以使用

org.ANTLR.V4.runtime.tree.gui.TreeViewer

您可以从中获得Hello演示。获得后，运行以下简单演示：

import java.util.Arrays;
import javax.swing.JFrame;
import javax.swing.JPanel;

import org.antlr.v4.runtime.ANTLRInputStream;
import org.antlr.v4.runtime.CharStream;
import org.antlr.v4.runtime.CommonTokenStream;
import org.antlr.v4.runtime.TokenStream;
import org.antlr.v4.runtime.tree.ParseTree;
import org.antlr.v4.runtime.tree.gui.TreeViewer;

/**
 * A simple demo to show AST GUI with ANTLR
 * @see http://www.antlr.org/api/Java/org/antlr/v4/runtime/tree/gui/TreeViewer.html
 * 
 * @author wangdq
 * 2014-5-24
 *
 */
public class HelloTestDrive {
    public static void main(String[] args) {
        //prepare token stream
        CharStream stream = new ANTLRInputStream("hello antlr");
        HelloLexer lexer  = new HelloLexer(stream);   
        TokenStream tokenStream = new CommonTokenStream(lexer);
        HelloParser parser = new HelloParser(tokenStream);
        ParseTree tree = parser.r(); 

        //show AST in console
        System.out.println(tree.toStringTree(parser));

        //show AST in GUI
        JFrame frame = new JFrame("Antlr AST");
        JPanel panel = new JPanel();
        TreeViewer viewer = new TreeViewer(Arrays.asList(
                parser.getRuleNames()),tree);
        viewer.setScale(1.5); // Scale a little
        panel.add(viewer);
        frame.add(panel);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
    }
}

然后，您将在控制台中获得AST打印，并在

JFrame

中显示。 详情请参阅

确保语法正常，然后可以修改此演示以满足您的要求

ANTLR 4的更新：

TreeViewer

已从迁移到

org.ANTLR.v4.gui.TreeViewer

包

使用

maven

时，

TreeViewer

需要以下依赖项：

<dependency>
    <groupId>org.antlr</groupId>
    <artifactId>antlr4</artifactId>
    <version>4.7.2</version>
</dependency>

org.antlr
antlr4
4.7.2

在antlr 4中使用import org.antlr.v4.runtime.tree.gui.TreeViewer…其工作原理：）

在尝试了几次自定义wangdq代码之后，我发现调用TreeViewer类的open方法可以获得一个令人愉快的（因为它已经完成了：）解析树检查器

应用于wangdq示例：

public class HelloTestDrive {
    public static void main(String[] args) {
        //prepare token stream
        CharStream stream = new ANTLRInputStream("hello antlr");
        HelloLexer lexer  = new HelloLexer(stream);   
        TokenStream tokenStream = new CommonTokenStream(lexer);
        HelloParser parser = new HelloParser(tokenStream);
        ParseTree tree = parser.r(); 

        //show AST in console
        System.out.println(tree.toStringTree(parser));

        //show AST in GUI
        TreeViewer viewr = new TreeViewer(Arrays.asList(
                parser.getRuleNames()),tree);
        viewr.open();
    }
}

---

ParseTree=parser.r（）中的
r
方法是什么返回？--我在解析器中没有看到返回
ParseTree
.ParseTree=parser.translationunit（）的方法；System.out.println（tree.toStringTree（解析器））；