我想在Python中使用ANTLR构建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
解析器: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
这将生成此文件列表:
然后我编写了这段代码来解析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
是这样的:
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;
}
当我运行此代码时,我得到了这个:
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?我没有写语法,只是从ANTLR存储库中提取的。
compilationUnit
,而不是您尝试解析的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 ;
必须称为
tree = parser.compilationUnit()