import org.antlr.v4.runtime.ANTLRFileStream; import org.antlr.v4.runtime.CommonTokenStream; public class TestU { public static void main(String[] args) throws Exception { ULexer t = new ULexer(new ANTLRFileStream(args[0])); CommonTokenStream tokens = new CommonTokenStream(t); UParser p = new UParser(tokens); p.setBuildParseTree(true); // ParserRuleContext r = p.s(); // System.out.println(r.toStringTree(p)); } }