String userDir = System.getProperty("user.dir");
String grammarName = userDir + "\\src\\main\\antlr4\\org\\ethereum\\serpent\\Serpent.g4";
String options[] = {grammarName, "-visitor", "-package", "org.ethereum.serpent"};
Tool tool = new Tool(options);
tool.outputDirectory = userDir + "\\src\\main\\java\\org\\ethereum\\serpent\\";
tool.processGrammarsOnCommandLine();
// org.antlr.Tool.main(new String[]{userDir + "\\src\\main\\antlr4\\org\\ethereum\\serpent\\Serpent.g4"});
}