antlr/tool/playground/TestL.java

import org.antlr.v4.runtime.*;

public class TestL {
	public static void main(String[] args) throws Exception {
		L lexer = new L(new ANTLRFileStream(args[0]));
		CommonTokenStream tokens = new CommonTokenStream(lexer);
		tokens.fill();
		System.out.println(tokens.getTokens());
	}
}