import org.antlr.v4.runtime.CharStream;
import org.antlr.v4.runtime.CommonTokenFactory;
import org.antlr.v4.runtime.CommonTokenStream;
import org.antlr.v4.runtime.DiagnosticErrorListener;
import org.antlr.v4.runtime.ParserRuleContext;
import org.antlr.v4.runtime.UnbufferedCharStream;

import java.io.FileInputStream;
import java.io.InputStream;

public class TestT {
	public static void main(String[] args) throws Exception {
		String inputFile = null;
		if ( args.length>0 ) inputFile = args[0];
		InputStream is = System.in;
		if ( inputFile!=null ) {
			is = new FileInputStream(inputFile);
		}
		CharStream input = new UnbufferedCharStream(is);

		TLexer lex = new TLexer(input);
		lex.setTokenFactory(new CommonTokenFactory(true));

		CommonTokenStream tokens = new CommonTokenStream(lex);
		TParser parser = new TParser(tokens);

		parser.addErrorListener(new DiagnosticErrorListener());

		parser.getInterpreter().setSLL(true);
		parser.setTrace(true);

		ParserRuleContext tree = parser.s();
		System.out.println(tree.toStringTree(parser));
//		tree.save(parser, "/tmp/t.ps");
	}
}

@@ -885,24 +885,26 @@
 stener());%0A%0A
+//
 %09%09parser.get
@@ -931,16 +931,18 @@
 (true);%0A
+//
 %09%09parser

tweak test