AjErl.Compiler.Lexer.NextToken C# (CSharp) Метод

        public Token NextToken()
        {
            if (this.tokens.Count > 0)
                return this.tokens.Pop();

            int ich = this.NextCharSkippingWhiteSpaces();

            if (ich == -1)
                return null;

            char ch = (char)ich;

            if (operators2.Any(op => op[0] == ch))
            {
                int ich2 = this.NextChar();

                if (ich2 >= 0)
                {
                    string op2 = ch.ToString() + ((char)ich2).ToString();

                    int ich3 = this.NextChar();

                    if (ich3 >= 0)
                    {
                        string op3 = op2 + ((char)ich3).ToString();

                        if (operators3.Contains(op3))
                            return new Token(op3, TokenType.Operator);

                        this.PushChar(ich3);
                    }

                    if (operators2.Contains(op2))
                        return new Token(op2, TokenType.Operator);

                    this.PushChar(ich2);
                }
            }

            if (separators2.Any(op => op[0] == ch))
            {
                int ich2 = this.NextChar();

                if (ich2 >= 0)
                {
                    string sep2 = ch.ToString() + ((char)ich2).ToString();

                    if (separators2.Contains(sep2))
                        return new Token(sep2, TokenType.Separator);

                    this.PushChar(ich2);
                }
            }

            if (operators.Contains(ch))
                return new Token(ch.ToString(), TokenType.Operator);
            if (separators.Contains(ch))
                return new Token(ch.ToString(), TokenType.Separator);

            if (char.IsDigit(ch))
                return this.NextInteger(ch);

            if (ch == '"')
                return this.NextString();

            if (IsNameChar(ch))
                return this.NextName(ch);

            throw new ParserException(string.Format("Unexpected '{0}'", ch));
        }

        public void GetArithmeticOperators()
        {
            Lexer lexer = new Lexer("+-*/");

            Token token = lexer.NextToken();

            Assert.IsNotNull(token);
            Assert.AreEqual(TokenType.Operator, token.Type);
            Assert.AreEqual("+", token.Value);

            token = lexer.NextToken();

            Assert.IsNotNull(token);
            Assert.AreEqual(TokenType.Operator, token.Type);
            Assert.AreEqual("-", token.Value);

            token = lexer.NextToken();

            Assert.IsNotNull(token);
            Assert.AreEqual(TokenType.Operator, token.Type);
            Assert.AreEqual("*", token.Value);

            token = lexer.NextToken();

            Assert.IsNotNull(token);
            Assert.AreEqual(TokenType.Operator, token.Type);
            Assert.AreEqual("/", token.Value);

            Assert.IsNull(lexer.NextToken());
        }