Antlr.Runtime.BufferedTokenStream.ToString C# (CSharp) Method

        public override string ToString()
        {
            if (_p == -1)
                Setup();

            Fill();
            return ToString(0, _tokens.Count - 1);
        }

        public void TestCompleteBuffer()
        {
            Grammar g = new Grammar(
                "lexer grammar t;\n" +
                "ID : 'a'..'z'+;\n" +
                "INT : '0'..'9'+;\n" +
                "SEMI : ';';\n" +
                "ASSIGN : '=';\n" +
                "PLUS : '+';\n" +
                "MULT : '*';\n" +
                "WS : ' '+;\n");
            // Tokens: 012345678901234567
            // Input:  x = 3 * 0 + 2 * 0;
            ICharStream input = new ANTLRStringStream("x = 3 * 0 + 2 * 0;");
            Interpreter lexEngine = new Interpreter(g, input);
            BufferedTokenStream tokens = new BufferedTokenStream(lexEngine);

            int i = 1;
            IToken t = tokens.LT(i);
            while (t.Type != CharStreamConstants.EndOfFile)
            {
                i++;
                t = tokens.LT(i);
            }
            tokens.LT(i++); // push it past end
            tokens.LT(i++);

            string result = tokens.ToString();
            string expecting = "x = 3 * 0 + 2 * 0;";
            Assert.AreEqual(expecting, result);
        }