我想在Python中使用ANTLR构建一个Java解析器
我从ANTLR存储库下载了语法:
Lexer:https://github.com/antlr/grammars-v4/blob/master/java/java/JavaLexer.g4
分析器:https://github.com/antlr/grammars-v4/blob/master/java/java/JavaParser.g4
然后,我使用script.bat生成了我需要的python代码:
java -jar antlr-4.8-complete.jar -Dlanguage=Python3 Java8Lexer.g4
java -jar antlr-4.8-complete.jar -Dlanguage=Python3 Java8Parser.g4
antlr-4.8-complete.jar
在这里下载:https://www.antlr.org/download/antlr-4.8-complete.jar
这将生成以下文件列表:
- Java8Lexer.interp
- Java8Lexer.py
- Java8Lexer.tokens
- Java8Parser.interp
- Java8Parser.py
- Java8Parser.tokens
- Java8ParserListener.py
然后我编写了以下代码来解析java文件:
import antlr4
from antlr4 import *
from java.antlr_unit2 import Java8Parser, Java8Lexer
def main():
code = open('test.txt', 'r').read()
lexer = Java8Lexer.Java8Lexer(antlr4.InputStream(code))
stream = antlr4.CommonTokenStream(lexer)
parser = Java8Parser.Java8Parser(stream)
tree = parser.expression()
print (tree)
if __name__ == '__main__':
main()
我的测试java代码test.txt
如下所示:
package org.jabref.gui.fieldeditors;
import java.util.ArrayList;
/**
* This class contains some code
*/
public class TextInputControlBehavior {
private static final boolean SHOW_HANDLES = Properties.IS_TOUCH_SUPPORTED && !OS.OS_X;
}
由于这段代码太短,下面是我要分析的代码示例:https://pastebin.com/KNxfasKQ
当我运行此代码时,我得到以下信息:
line 1:0 extraneous input 'package' expecting {'boolean', 'byte', 'char', 'double', 'float', 'int', 'long', 'new', 'short', 'super', 'this', 'void', IntegerLiteral, FloatingPointLiteral, BooleanLiteral, CharacterLiteral, StringLiteral, 'null', '(', '!', '~', '++', '--', '+', '-', Identifier, '@'}
[]
我做错什么了吗?语法不是我写的,我只是从ANTLR repo那里拿的
编辑:帕维尔·斯米尔诺夫的回答帮助了我,现在我没有得到警告。但是现在这个程序看起来很慢,我得到了一个空的树作为输出
解决了:我正在打印tree
,但我必须print(tree.toStringTree(recog=parser))
最后的代码是:
import antlr4 from antlr4 import * from java.antlr_unit2 import Java8Parser, Java8Lexer def main(): code = open('test.txt', 'r').read() lexer = Java8Lexer.Java8Lexer(antlr4.InputStream(code)) stream = antlr4.CommonTokenStream(lexer) parser = Java8Parser.Java8Parser(stream) tree = parser.compilationUnit() print(tree.toStringTree(recog=parser)) if __name__ == '__main__': main()
您的文本文件包含一个compilationUnit
,而不是您试图用其进行解析的expression
tree = parser.expression()
仔细查看解析器规则,您需要的规则是
compilationUnit
: packageDeclaration? importDeclaration* typeDeclaration* EOF
;
必须称之为
tree = parser.compilationUnit()
标签:__,Java,antlr,ANTLR,Java8Parser,Python,antlr4,java,Java8Lexer
From: https://www.cnblogs.com/hushaojun/p/16731689.html