public void CurrentTest()
        {
            Write("current.txt", "scary Variable  ");
            StreamReader stream = new StreamReader("C:\\current.txt");

            scanner = new PrologScanner(stream);
            scanner.Next();
            Assert.AreEqual(PrologToken.ATOM, scanner.Current.Kind);

            scanner.Next();
            Assert.AreEqual(PrologToken.VARIABLE, scanner.Current.Kind);

            stream.Close();
        }
        public void RParenTest()
        {
            Write("rparen.txt", "     )  ");
            StreamReader stream = new StreamReader("C:\\rparen.txt");

            scanner = new PrologScanner(stream);
            scanner.Next();
            Assert.AreEqual(PrologToken.RPAREN, scanner.Current.Kind);
            stream.Close();
        }
        public void VariableTest()
        {
            Write("var.txt", "Father  ");
            StreamReader stream = new StreamReader("C:\\var.txt");

            scanner = new PrologScanner(stream);
            scanner.Next();
            Assert.AreEqual(PrologToken.VARIABLE, scanner.Current.Kind);
            stream.Close();
        }
        public void AtomTest()
        {
            Write("atom.txt", " atom  ");
            StreamReader stream = new StreamReader("C:\\atom.txt");

            scanner = new PrologScanner(stream);
            scanner.Next();
            Assert.AreEqual(PrologToken.ATOM, scanner.Current.Kind);
            stream.Close();
        }
        public void CommaTest()
        {
            Write("comma.txt", " ,  ");
            StreamReader stream = new StreamReader("C:\\comma.txt");

            scanner = new PrologScanner(stream);
            scanner.Next();
            Assert.AreEqual(PrologToken.COMMA, scanner.Current.Kind);
            stream.Close();
        }
        public void ListSepTest()
        {
            Write("sep.txt", " |  ");
            StreamReader stream = new StreamReader("C:\\sep.txt");

            scanner = new PrologScanner(stream);
            scanner.Next();
            Assert.AreEqual(PrologToken.LIST_SEP, scanner.Current.Kind);
            stream.Close();
        }
        public void RBracketTest()
        {
            Write("rbra.txt", " ]  ");
            StreamReader stream = new StreamReader("C:\\rbra.txt");

            scanner = new PrologScanner(stream);
            scanner.Next();
            Assert.AreEqual(PrologToken.RBRACKET, scanner.Current.Kind);
            stream.Close();
        }
        public void DotTest()
        {
            Write("dot.txt", " . ");
            StreamReader stream = new StreamReader("C:\\dot.txt");

            scanner = new PrologScanner(stream);
            scanner.Next();
            Assert.AreEqual(PrologToken.DOT, scanner.Current.Kind);
            stream.Close();
        }
        public void StringTest()
        {
            Write("string.txt", " 'This is a string'  ");

            StreamReader stream = new StreamReader("C:\\string.txt");

            scanner = new PrologScanner(stream);
            scanner.Next();
            Assert.AreEqual(PrologToken.ATOM, scanner.Current.Kind);
            stream.Close();
        }
        public void FactTokensRule()
        {
            Write("fact_tokens.txt", "male(ali,hodroj,X,'Fine not really!',[A|B]).");
            StreamReader stream = new StreamReader("C:\\fact_tokens.txt");

            scanner = new PrologScanner(stream);
            // male
            scanner.Next();
            Assert.AreEqual(PrologToken.ATOM, scanner.Current.Kind);

            // (
            scanner.Next();
            Assert.AreEqual(PrologToken.LPAREN, scanner.Current.Kind);

            // ali
            scanner.Next();
            Assert.AreEqual(PrologToken.ATOM, scanner.Current.Kind);

            // ,
            scanner.Next();
            Assert.AreEqual(PrologToken.COMMA, scanner.Current.Kind);

            // hodroj
            scanner.Next();
            Assert.AreEqual(PrologToken.ATOM, scanner.Current.Kind);

            // ,
            scanner.Next();
            Assert.AreEqual(PrologToken.COMMA, scanner.Current.Kind);

            // X
            scanner.Next();
            Assert.AreEqual(PrologToken.VARIABLE, scanner.Current.Kind);

            // ,
            scanner.Next();
            Assert.AreEqual(PrologToken.COMMA, scanner.Current.Kind);

            // 'Fine Not Really!'
            scanner.Next();
            Assert.AreEqual(PrologToken.ATOM, scanner.Current.Kind);

            // ,
            scanner.Next();
            Assert.AreEqual(PrologToken.COMMA, scanner.Current.Kind);


            // [
            scanner.Next();
            Assert.AreEqual(PrologToken.LBRACKET, scanner.Current.Kind);

            // A
            scanner.Next();
            Assert.AreEqual(PrologToken.VARIABLE, scanner.Current.Kind);

            // |
            scanner.Next();
            Assert.AreEqual(PrologToken.LIST_SEP, scanner.Current.Kind);

            // B
            scanner.Next();
            Assert.AreEqual(PrologToken.VARIABLE, scanner.Current.Kind);

            // ]
            scanner.Next();
            Assert.AreEqual(PrologToken.RBRACKET, scanner.Current.Kind);

            // )
            scanner.Next();
            Assert.AreEqual(PrologToken.RPAREN, scanner.Current.Kind);


            // .
            scanner.Next();
            Assert.AreEqual(PrologToken.DOT, scanner.Current.Kind);

            stream.Close();
        }