diff --git a/Canon.Core/Enums/SemanticEnums.cs b/Canon.Core/Enums/SemanticEnums.cs
index a334e37..6057329 100644
--- a/Canon.Core/Enums/SemanticEnums.cs
+++ b/Canon.Core/Enums/SemanticEnums.cs
@@ -8,14 +8,12 @@ public enum SemanticTokenType
     Delimiter,
     Identifier,
     Character,
+    Empty,
+    Error,  // 加了一个错误token
     /// <summary>
     /// 语法分析中的栈底符号
     /// </summary>
-    End,
-    /// <summary>
-    /// 语法分析中的空串符号
-    /// </summary>
-    Empty
+    End
 }
 
 public enum DelimiterType
@@ -89,3 +87,11 @@ public enum NumberType
     Real,
     Hex
 }
+
+public enum StateType
+{
+    Word,
+    Digit,
+    Delimiter,
+    Other
+}
diff --git a/Canon.Core/LexicalParser/Lexer.cs b/Canon.Core/LexicalParser/Lexer.cs
index 3d618d3..516de9b 100644
--- a/Canon.Core/LexicalParser/Lexer.cs
+++ b/Canon.Core/LexicalParser/Lexer.cs
@@ -1,92 +1,677 @@
-namespace Canon.Core.LexicalParser;
+using System.Text;
+using Canon.Core.Enums;
 
-public class Lexer
+namespace Canon.Core.LexicalParser;
+
+public class Lexer(string source)
 {
-    private readonly LinkedList<char> _source;
-    private LinkedListNode<char>? _currentNode;
-    private uint _line = 1;
-    private uint _charPosition;
-    private readonly List<SemanticToken> _tokens = [];
 
-    public Lexer(string source)
+    // 保留关键字
+    private readonly string[] _keywords =
+    [
+        "Program", "Const", "Var", "Procedure",
+        "Function", "Begin", "End", "Array",
+        "Of", "If", "Then", "Else",
+        "For", "To", "Do", "Integer",
+        "Real", "Boolean", "Character", "Divide",
+        "Not", "Mod", "And", "Or"
+    ];
+
+    private readonly string[] _delimiter = [";", ",", ":", ".", "(", ")", "[", "]","'","\"",".."];
+
+    // 状态机
+    private StateType _state;
+    private char _ch;
+
+    private LinkedList<char> _token = new LinkedList<char>();
+    // bool save;
+    // int saved_state;
+    bool _finish;
+    private bool eof;
+
+    //缓冲区
+    private readonly char[] _buffer = new char[2048];
+    // int start_pos;
+    private int _fwdPos;
+
+    // 计数器
+    private uint _line = 1;
+    private uint _chPos;
+    private int _sourcePos;
+    private readonly Dictionary<SemanticTokenType, int> _tokenCount = new Dictionary<SemanticTokenType, int>
     {
-        // 将字符串转换为LinkedList<char>
-        _source = new LinkedList<char>(source);
-        _currentNode = _source.First;
-    }
+        { SemanticTokenType.Keyword, 0 },
+        { SemanticTokenType.Number, 0 },
+        { SemanticTokenType.Operator, 0 },
+        { SemanticTokenType.Delimiter, 0 },
+        { SemanticTokenType.Identifier, 0 },
+        { SemanticTokenType.Character, 0 },
+        { SemanticTokenType.Error, 0 },
+        { SemanticTokenType.End, 0 }
+    };
+
+    private readonly List<SemanticToken> _tokens = [];
 
     public List<SemanticToken> Tokenize()
     {
-        while (_currentNode != null)
-        {
-            _charPosition = 0; // 重置字符位置
-            SkipWhitespace();
+        // 缓冲区
+        // start_pos = 0;
+        _fwdPos = 0;
+        FillLeftBuffer();
 
-            if (_currentNode == null) break; // 如果跳过空格后到达了末尾，则退出循环
+        // 状态机
+        _finish = false;
 
-            SemanticToken? token = null;
+        while (!_finish) {
+            GetChar();
+            GetNbc();
 
-            // 尝试解析各种类型的词法单元
-            if (DelimiterSemanticToken.TryParse(_line, _charPosition, _currentNode, out var delimiterToken))
-            {
-                token = delimiterToken;
-            }
-            else if (CharacterSemanticToken.TryParse(_line, _charPosition, _currentNode, out var characterToken))
-            {
-                token = characterToken;
-            }
-            else if (KeywordSemanticToken.TryParse(_line, _charPosition, _currentNode, out var keywordToken))
-            {
-                token = keywordToken;
-            }
-            else if (OperatorSemanticToken.TryParse(_line, _charPosition, _currentNode, out var operatorToken))
-            {
-                token = operatorToken;
-            }
-            else if (NumberSemanticToken.TryParse(_line, _charPosition, _currentNode, out var numberToken))
-            {
-                token = numberToken;
-            }
-            else if (IdentifierSemanticToken.TryParse(_line, _charPosition, _currentNode, out var identifierToken))
-            {
-                token = identifierToken;
-            }
+            _token = new LinkedList<char>();
 
-            if (token != null)
-            {
-                _tokens.Add(token);
-                // 根据词法单元的长度移动currentNode
-                MoveCurrentNode(token.LiteralValue.Length);
+            if (IsLetter()) {
+                _state = StateType.Word;
+            }
+            else if (IsDigit()) {
+                _state = StateType.Digit;
+            }
+            else if (IsDelimiter()) {
+                _state = StateType.Delimiter;
             }
             else
             {
-                // 未能识别的字符，跳过
-                MoveCurrentNode(1);
+                _state = StateType.Other;
             }
-        }
 
-        // tokens.Add(new EOFToken(line, charPosition)); // 添加EOF标记
+            switch (_state)
+            {
+            case StateType.Word: {
+                while (IsDigit() || IsLetter())
+                {
+                    Cat();
+                    GetChar();
+                }
+                Retract();
+
+                if (IsKeyword())
+                {
+                    KeywordType keywordType =
+                        KeywordSemanticToken.GetKeywordTypeByKeyword(LinkedListToString(_token.First));
+                    MakeToken(keywordType);
+                }
+                else {
+                    MakeToken(SemanticTokenType.Identifier);
+                }
+                break;
+            }
+
+            case StateType.Digit:
+                {
+                    bool error = false;
+                    bool tag = false; // 用于标记是否已经处理过科学记数法的指数部分
+                    bool doubleDot = false;
+                    NumberType numberType = NumberType.Integer;
+
+                    while (IsDigit() || _ch == '.' || _ch == 'E' || _ch == '+' || _ch == '-' || _ch == 'e' || IsLetter()) {
+                        if (_ch != '.')
+                        {
+                            Cat();
+                        }
+
+
+                        if (_ch == '0' && !tag) {
+                            GetChar();
+                            if (_ch == 'x' || _ch == 'X') {
+                                numberType = NumberType.Hex;    // 标识十六进制
+                                Cat();
+                                while (IsHexDigit()) { // 假设IsHexDigit方法能够识别十六进制数字
+                                    Cat();
+                                }
+                                break;
+                            }
+                            Retract(); // 如果不是'x'或'X'，回退一个字符
+                        }
+                        else if (_ch == '.') {
+                            GetChar();
+                            if (_ch == '.') {
+                                Retract(); // 回退到第一个'.'
+                                Retract(); // 回退到'.'之前的数字
+                                doubleDot = true;
+                                break;
+                            }
+                            Retract();
+                            Cat();
+                            numberType = NumberType.Real;
+                        }
+                        else if ((_ch == 'e' || _ch == 'E') && !tag) {
+                            GetChar();
+                            if (IsDigit() || _ch == '+' || _ch == '-') {
+                                Cat();
+                                tag = true; // 已处理指数部分
+                                continue;
+                            }
+                            error = true; // 错误的科学记数法
+                            break;
+                        }
+
+                        GetChar();
+                    }
+
+                    if (!error) {
+                        MakeToken(numberType);
+                        if (doubleDot)
+                        {
+                            break;
+                        }
+                        Retract();
+                    }
+                    else
+                    {
+                        Retract();
+                        PrintError(0,_token.First,_line);
+                        _tokenCount[SemanticTokenType.Error]++;
+                    }
+                    break;
+                }
+
+            case StateType.Delimiter:
+                Cat();
+                switch (_ch)
+                {
+                case '.':
+                    {
+                        GetChar();
+                        if (_ch == '.')
+                        {
+                            Cat();
+                            MakeToken(DelimiterType.DoubleDots);
+                            break;
+                        }
+                        Retract();
+                        if (IsPeriod())
+                        {
+
+                        }else if (IsDot())
+                        {
+
+                        }
+                    }
+                    break;
+                case '\'':
+                case '\"':
+                    {
+                        if(_ch == '\'') MakeToken(DelimiterType.SingleQuotation);
+                        else if(_ch == '\"') MakeToken(DelimiterType.DoubleQuotation);
+
+                        // 重置_token，准备收集字符串内容
+                        _token = new LinkedList<char>();
+
+                        GetChar(); // 移动到下一个字符，即字符串的第一个字符
+                        while (_ch != '\'' && _ch != '\"')
+                        {
+                            Cat(); // 收集字符
+                            GetChar(); // 移动到下一个字符
+                        }
+
+                        // 在退出循环时，_ch为'或EOF，此时_token包含字符串内容
+                        // 创建字符内容的token，注意这里使用SemanticTokenType.String表示字符串字面量
+                        MakeToken(SemanticTokenType.Character); // 或其它适用于字符串字面量的SemanticTokenType
+                        _token = new LinkedList<char>(); // 重置_token
+
+                        if (_ch == '\'' && _ch != '\n')
+                        {
+                            // 识别并创建最后一个单引号的token
+                            Cat();
+                            MakeToken(DelimiterType.SingleQuotation);
+                        }
+                        else if (_ch == '\"')
+                        {
+                            Cat();
+                            MakeToken(DelimiterType.DoubleQuotation);
+                        }
+                        else
+                        {
+                            // 这里处理遇到EOF但没有闭合单引号的情况，例如：'字符串结尾没有单引号
+                            // 可以添加错误处理代码
+                            PrintError(0, _token.First, _line); // 假设这个方法用于打印错误
+                        }
+                    }
+                    break;
+                case ',':
+                    MakeToken(DelimiterType.Comma);
+                    break;
+                case ':':
+                    MakeToken(DelimiterType.Colon);
+                    break;
+                case ';':
+                    MakeToken(DelimiterType.Semicolon);
+                    break;
+                case '(':
+                    MakeToken(DelimiterType.LeftParenthesis);
+                    break;
+                case ')':
+                    MakeToken(DelimiterType.RightParenthesis);
+                    break;
+                case '[':
+                    MakeToken(DelimiterType.LeftSquareBracket);
+                    break;
+                case ']':
+                    MakeToken(DelimiterType.RightSquareBracket);
+                    break;
+                }
+                break;
+
+            case StateType.Other:
+                DealOther();
+                break;
+            default:
+                throw new ArgumentOutOfRangeException();
+            }
+
+        }
+        PrintResult();
         return _tokens;
     }
 
-    private void SkipWhitespace()
+    private bool IsDot()
     {
-        while (_currentNode != null && char.IsWhiteSpace(_currentNode.Value))
+        SemanticToken tokenBefore = _tokens.Last();
+        if (tokenBefore.TokenType == SemanticTokenType.Identifier) return true;
+        return false;
+    }
+
+    private bool IsPeriod()
+    {
+        SemanticToken tokenBefore = _tokens.Last();
+        if (tokenBefore.TokenType == SemanticTokenType.Keyword) return true;
+        return false;
+    }
+
+    private void DealOther()
+    {
+        switch (_ch)
         {
-            if (_currentNode.Value == '\n')
-            {
-                _line++;
-                _charPosition = 0;
-            }
-            _currentNode = _currentNode.Next;
+            case '+': // 识别 +
+                Cat();
+                MakeToken(OperatorType.Plus);
+                break;
+            case '-': // 识别 -
+                Cat();
+                MakeToken(OperatorType.Minus);
+                break;
+            case '*': // 识别 *
+                Cat();
+                MakeToken(OperatorType.Multiply);
+                break;
+            case '/': // 识别 /
+                Cat();
+                MakeToken(OperatorType.Divide);
+                break;
+            case '=':
+                Cat();
+                MakeToken(OperatorType.Equal);
+                break;
+            case '<':
+                Cat();
+                GetChar();
+                if (_ch == '=')
+                {
+                    // 识别 <=
+                    Cat();
+                    MakeToken(OperatorType.LessEqual);
+                }
+                else if(_ch == '>')
+                {
+                    // 识别 <>
+                    Cat();
+                    MakeToken(OperatorType.NotEqual);
+                }
+                else
+                {
+                    // 识别 <
+                    Retract();
+                    MakeToken(OperatorType.Less);
+                }
+                break;
+            case '>':
+                Cat();
+                GetChar();
+                if (_ch == '=')
+                {
+                    // 识别 >=
+                    Cat();
+                    MakeToken(OperatorType.GreaterEqual);
+                }
+                else
+                {
+                    // 识别 >
+                    Retract();
+                    MakeToken(OperatorType.Greater);
+                }
+                break;
+            case ':':
+                Cat();
+                GetChar();
+                if (_ch == '=')
+                {
+                    // 识别 :=
+                    Cat();
+                    MakeToken(OperatorType.Assign);
+                }
+                else
+                {
+                    // 这里应该被识别为delimiter逻辑上
+                    Cat();
+                    PrintError(1, _token.First, _line);
+                    _tokenCount[SemanticTokenType.Error]++;
+                }
+                break;
+            default:
+                Cat();
+                PrintError(1, _token.First, _line);
+                _tokenCount[SemanticTokenType.Error]++;
+                break;
         }
     }
 
-    private void MoveCurrentNode(int steps)
+    private void MakeToken(SemanticTokenType tokenType)
     {
-        for (int i = 0; i < steps && _currentNode != null; i++)
+        SemanticToken? token;
+        if (_token.First == null)
         {
-            _currentNode = _currentNode.Next;
+            Console.WriteLine("11");
+        }
+        switch (tokenType)
+        {
+            case SemanticTokenType.Character:
+                CharacterSemanticToken characterSemanticToken = new CharacterSemanticToken()
+                {
+                    LinePos = _line, CharacterPos = _chPos, LiteralValue = LinkedListToString(_token.First),
+                };
+                token = characterSemanticToken;
+                break;
+            case SemanticTokenType.Identifier:
+                IdentifierSemanticToken identifierSemanticToken = new IdentifierSemanticToken()
+                {
+                    LinePos = _line, CharacterPos = _chPos, LiteralValue = LinkedListToString(_token.First),
+                };
+                token = identifierSemanticToken;
+                break;
+            case SemanticTokenType.Error:
+                ErrorSemanticToken errorSemanticToken = new ErrorSemanticToken()
+                {
+                    LinePos = _line, CharacterPos = _chPos, LiteralValue = LinkedListToString(_token.First),
+                };
+                token = errorSemanticToken;
+                break;
+
+            default:
+                throw new ArgumentOutOfRangeException(nameof(tokenType), tokenType, null);
+        }
+
+        if (token != null)
+        {
+            _tokens.Add(token);
+            _tokenCount[tokenType]++;
+            Console.WriteLine($"<{tokenType}>");
+            Console.WriteLine(LinkedListToString(_token.First));
+        }
+
+
+    }
+
+    private void MakeToken(KeywordType keywordType)
+    {
+        KeywordSemanticToken keywordSemanticToken = new KeywordSemanticToken
+        {
+            LinePos = _line,
+            CharacterPos = _chPos,
+            LiteralValue = LinkedListToString(_token.First),
+            KeywordType = keywordType
+        };
+        _tokens.Add(keywordSemanticToken);
+        _tokenCount[SemanticTokenType.Keyword]++;
+        Console.WriteLine($"<{SemanticTokenType.Keyword}> <{keywordType}>");
+        Console.WriteLine(LinkedListToString(_token.First));
+    }
+
+    private void MakeToken(DelimiterType delimiterType)
+    {
+        DelimiterSemanticToken delimiterSemanticToken = new DelimiterSemanticToken()
+        {
+            LinePos = _line,
+            CharacterPos = _chPos,
+            LiteralValue = LinkedListToString(_token.First),
+            DelimiterType = delimiterType
+        };
+        _tokens.Add(delimiterSemanticToken);
+        _tokenCount[SemanticTokenType.Delimiter]++;
+        Console.WriteLine($"<{SemanticTokenType.Delimiter}> <{delimiterType}>");
+        Console.WriteLine(LinkedListToString(_token.First));
+    }
+
+    private void MakeToken(OperatorType operatorType)
+    {
+        OperatorSemanticToken operatorSemanticToken = new OperatorSemanticToken()
+        {
+            LinePos = _line,
+            CharacterPos = _chPos,
+            LiteralValue = LinkedListToString(_token.First),
+            OperatorType = operatorType
+        };
+        _tokens.Add(operatorSemanticToken);
+        _tokenCount[SemanticTokenType.Operator]++;
+        Console.WriteLine($"<{SemanticTokenType.Operator}> <{operatorType}>");
+        Console.WriteLine(LinkedListToString(_token.First));
+    }
+
+    private void MakeToken(NumberType numberType)
+    {
+        NumberSemanticToken numberSemanticToken = new NumberSemanticToken()
+        {
+            LinePos = _line,
+            CharacterPos = _chPos,
+            LiteralValue = LinkedListToString(_token.First),
+            NumberType = numberType
+        };
+        _tokens.Add(numberSemanticToken);
+        _tokenCount[SemanticTokenType.Number]++;
+        Console.WriteLine($"<{SemanticTokenType.Number}> <{numberType}>");
+        Console.WriteLine(LinkedListToString(_token.First));
+    }
+
+    // 填充buffer操作
+    private void FillLeftBuffer() {
+        //cout << "fill left" << endl;
+        for (int i = 0; i < _buffer.Length / 2; i++) {
+            _buffer[i] = '$';
+        }
+
+        // 确保source字符串足够长，避免超出范围
+        int lengthToCopy = Math.Min(_buffer.Length / 2 - 1, source.Length - _sourcePos);
+
+        // 使用Array.Copy方法
+        Array.Copy(source.ToCharArray(), _sourcePos, _buffer, 0, lengthToCopy);
+
+        _sourcePos += lengthToCopy;
+
+        if (_sourcePos == source.Length) {
+            eof = true;
+        }
+    }
+
+    private void FillRightBuffer() {
+        //cout << "fill right" << endl;
+        for (int i = _buffer.Length / 2; i < _buffer.Length; i++) {
+            _buffer[i] = '$';
+        }
+
+        // 确保source字符串足够长，避免超出范围
+        int lengthToCopy = Math.Min(_buffer.Length / 2 - 1, source.Length - _sourcePos);
+
+        // 使用Array.Copy方法
+        Array.Copy(source.ToCharArray(), _sourcePos, _buffer, _buffer.Length / 2, lengthToCopy);
+
+        _sourcePos += lengthToCopy;
+
+        if (_sourcePos == source.Length) {
+            eof = true;
+        }
+    }
+
+    private void PrintBuffer() {
+        for (int i = 0; i < _buffer.Length; i++) {
+            Console.WriteLine($"[{i}] {_buffer[i]}");
+        }
+    }
+
+    void DealEof() {
+        if (eof) _finish = true;
+        else if (_fwdPos < _buffer.Length / 2) {
+            FillRightBuffer();
+            _fwdPos = _buffer.Length / 2;
+        }
+        else {
+            FillLeftBuffer();
+            // start_pos = 0;
+            _fwdPos = 0;
+        }
+    }
+
+    // 读取buffer操作
+    void GetChar() {
+        if (_fwdPos >= 0 && _fwdPos < _buffer.Length) _ch = _buffer[_fwdPos];
+        _chPos++;
+        if (_ch == '$') {
+            DealEof();
+            if (_fwdPos >= 0 && _fwdPos < _buffer.Length) _ch = _buffer[_fwdPos];
+        }
+        if (_fwdPos < _buffer.Length) _fwdPos++;
+    }
+
+    private void GetNbc() {
+        while (_ch == ' ' || _ch == '\n' || _ch == '\t' || _ch == '\r') {
+            if (_ch == '\n') {
+                _line++;
+                _chPos = 0;
+            }
+            GetChar();
+        }
+    }
+
+    private void Retract() {
+        _fwdPos -= 2;
+        _chPos -= 2;
+        GetChar();
+    }
+
+    private void Cat()
+    {
+        _token.AddLast(_ch);
+        // cout << "加入" << ch << endl;
+    }
+
+    private string LinkedListToString(LinkedListNode<char> first)
+    {
+        // 使用 StringBuilder 来构建字符串
+        StringBuilder sb = new StringBuilder();
+        for (LinkedListNode<char> node = first; node != null; node = node.Next)
+        {
+            sb.Append(node.Value);
+        }
+
+        // 将 StringBuilder 的内容转换为字符串
+        string result = sb.ToString();
+
+        return result;
+    }
+
+    // 判断字符
+    private bool IsDigit() {
+        if (_ch >= '0' && _ch <= '9') return true;
+        return false;
+    }
+
+    private bool IsHexDigit()
+    {
+        if ((_ch >= '0' && _ch <= '9') || (_ch<= 'F' && _ch >= 'A')) return true;
+        return false;
+    }
+
+    private bool IsLetter() {
+        if ((_ch >= 'A' && _ch <= 'Z') || (_ch >= 'a' && _ch <= 'z' || _ch == '_')) {
+            return true;
+        }
+        return false;
+    }
+
+    private bool IsKeyword()
+    {
+        string tokenString = LinkedListToString(_token.First);
+
+        foreach (var t in _keywords)
+        {
+            if (string.Equals(tokenString, t, StringComparison.OrdinalIgnoreCase)) return true;
+        }
+        return false;
+    }
+
+
+    private bool IsDelimiter()
+    {
+        foreach (var delimiter in _delimiter)
+        {
+            if (delimiter.Contains(_ch))
+            {
+                if (_ch != ':')
+                {
+                    return true;
+                }
+
+                GetChar();
+                if (_ch == '=')
+                {
+                    Retract();
+                    return false;
+                }
+
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private void PrintToken(SemanticTokenType type, LinkedListNode<char> token, uint line)
+    {
+        string tokenString = LinkedListToString(token);
+        string typeName = Enum.GetName(typeof(SemanticTokenType), type) ?? "Unknown";
+        Console.WriteLine($"{line} <{typeName.ToUpperInvariant()},{tokenString}>");
+    }
+
+    // PrintToken(SemanticTokenType.Keyword, "if", 42); // 假设'if'是token，42是行号
+
+    private void PrintError(int type, LinkedListNode<char> token, uint line)
+    {
+        string tokenString = LinkedListToString(token);
+        switch (type)
+        {
+            case 0:
+                Console.WriteLine($"{line} <ERROR,{tokenString}>");
+                break;
+            case 1:
+                Console.WriteLine($"{line} <ERROR,@>");
+                break;
+        }
+    }
+
+    // PrintError(0, "unexpected symbol", 42); // 假设 "unexpected symbol" 是错误的 token，42 是行号
+
+    private void PrintResult()
+    {
+        Console.WriteLine(_line);
+        foreach (var pair in _tokenCount)
+        {
+            Console.WriteLine($"{pair.Key}: {pair.Value}");
         }
     }
 }
+
diff --git a/Canon.Core/LexicalParser/SemanticToken.cs b/Canon.Core/LexicalParser/SemanticToken.cs
index 72d8cf3..8e42917 100644
--- a/Canon.Core/LexicalParser/SemanticToken.cs
+++ b/Canon.Core/LexicalParser/SemanticToken.cs
@@ -129,6 +129,46 @@ public class KeywordSemanticToken : SemanticToken
 
     public required KeywordType KeywordType { get; init; }
 
+    public static readonly Dictionary<string, KeywordType> KeywordTypes = new Dictionary<string, KeywordType>(StringComparer.OrdinalIgnoreCase)
+    {
+        { "program", KeywordType.Program },
+        { "const", KeywordType.Const },
+        { "var", KeywordType.Var },
+        { "procedure", KeywordType.Procedure },
+        { "function", KeywordType.Function },
+        { "begin", KeywordType.Begin },
+        { "end", KeywordType.End },
+        { "array", KeywordType.Array },
+        { "of", KeywordType.Of },
+        { "if", KeywordType.If },
+        { "then", KeywordType.Then },
+        { "else", KeywordType.Else },
+        { "for", KeywordType.For },
+        { "to", KeywordType.To },
+        { "do", KeywordType.Do },
+        { "integer", KeywordType.Integer },
+        { "real", KeywordType.Real },
+        { "boolean", KeywordType.Boolean },
+        { "character", KeywordType.Character },
+        { "div", KeywordType.Divide }, // 注意: Pascal 使用 'div' 而不是 '/'
+        { "not", KeywordType.Not },
+        { "mod", KeywordType.Mod },
+        { "and", KeywordType.And },
+        { "or", KeywordType.Or }
+    };
+
+    public static KeywordType GetKeywordTypeByKeyword(string keyword)
+    {
+        if (KeywordTypes.TryGetValue(keyword, out var keywordType))
+        {
+            return keywordType;
+        }
+        else
+        {
+            throw new ArgumentException($"Unknown keyword: {keyword}");
+        }
+    }
+
     public static bool TryParse(uint linePos, uint characterPos, LinkedListNode<char> now,
         out KeywordSemanticToken? token)
     {
@@ -200,7 +240,6 @@ public class OperatorSemanticToken : SemanticToken
 /// <summary>
 /// 数值类型记号
 /// </summary>
-/// TODO：进制表示（只有$1的十六进制表示）
 public class NumberSemanticToken : SemanticToken
 {
     public override SemanticTokenType TokenType => SemanticTokenType.Number;
@@ -287,3 +326,19 @@ public class EndSemanticToken : SemanticToken
 {
     public override SemanticTokenType TokenType => SemanticTokenType.End;
 }
+
+/// <summary>
+/// 错误类型记号
+/// </summary>
+public class ErrorSemanticToken : SemanticToken
+{
+    public override SemanticTokenType TokenType => SemanticTokenType.Error;
+
+    public static bool TryParse(uint linePos, uint characterPos, LinkedListNode<char> now,
+        out IdentifierSemanticToken? token)
+    {
+        token = null;
+        return false;
+    }
+}
+
diff --git a/Canon.Tests/LexicalParserTests/Array.cs b/Canon.Tests/LexicalParserTests/Array.cs
deleted file mode 100644
index abd8c40..0000000
--- a/Canon.Tests/LexicalParserTests/Array.cs
+++ /dev/null
@@ -1,6 +0,0 @@
-namespace Canon.Tests.LexicalParserTests;
-
-public class Array
-{
-    
-}
diff --git a/Canon.Tests/LexicalParserTests/DelimiterTests.cs b/Canon.Tests/LexicalParserTests/DelimiterTests.cs
index 4c7e5a9..5b653db 100644
--- a/Canon.Tests/LexicalParserTests/DelimiterTests.cs
+++ b/Canon.Tests/LexicalParserTests/DelimiterTests.cs
@@ -3,7 +3,6 @@ using Canon.Core.LexicalParser;
 
 namespace Canon.Tests.LexicalParserTests;
 
-
 public class DelimiterTests
 {
     [Theory]
@@ -17,11 +16,12 @@ public class DelimiterTests
     [InlineData("]asd", DelimiterType.RightSquareBracket)]
     public void SmokeTest(string input, DelimiterType type)
     {
-        LinkedList<char> content = Utils.GetLinkedList(input);
+        Lexer lexer = new(input);
+        List<SemanticToken> tokens = lexer.Tokenize();
 
-        Assert.True(DelimiterSemanticToken.TryParse(0, 0, content.First!,
-            out DelimiterSemanticToken? token));
-        Assert.NotNull(token);
-        Assert.Equal(type, token.DelimiterType);
+        SemanticToken token = tokens[0];
+        Assert.Equal(SemanticTokenType.Delimiter, token.TokenType);
+        DelimiterSemanticToken delimiterSemanticToken = (DelimiterSemanticToken)token;
+        Assert.Equal(type, delimiterSemanticToken.DelimiterType);
     }
 }
diff --git a/Canon.Tests/LexicalParserTests/IndentifierTests.cs b/Canon.Tests/LexicalParserTests/IndentifierTests.cs
index cfb657e..a46a10b 100644
--- a/Canon.Tests/LexicalParserTests/IndentifierTests.cs
+++ b/Canon.Tests/LexicalParserTests/IndentifierTests.cs
@@ -18,20 +18,13 @@ namespace Canon.Tests.LexicalParserTests
         [InlineData("identifier_with_special_chars@#", false)]
         [InlineData("", false)]
         [InlineData(" ", false)]
-        [InlineData("andand",false)]
+        [InlineData("andand", false)]
         public void TestParseIdentifier(string input, bool expectedResult)
         {
-            LinkedList<char> content = Utils.GetLinkedList(input);
-            Assert.Equal(expectedResult, IdentifierSemanticToken.TryParse(0, 0, content.First!,
-                out IdentifierSemanticToken? token));
-            if (expectedResult)
-            {
-                Assert.NotNull(token);
-            }
-            else
-            {
-                Assert.Null(token);
-            }
+            Lexer lexer = new(input);
+            List<SemanticToken> tokens = lexer.Tokenize();
+
+            Assert.Equal(expectedResult, tokens.FirstOrDefault()?.TokenType == SemanticTokenType.Identifier);
         }
     }
 }
diff --git a/Canon.Tests/LexicalParserTests/KeywordTypeTests.cs b/Canon.Tests/LexicalParserTests/KeywordTypeTests.cs
index e36d149..fd22191 100644
--- a/Canon.Tests/LexicalParserTests/KeywordTypeTests.cs
+++ b/Canon.Tests/LexicalParserTests/KeywordTypeTests.cs
@@ -23,11 +23,12 @@ public class KeywordTypeTests
     [InlineData("do", KeywordType.Do)]
     public void SmokeTest(string input, KeywordType type)
     {
-        LinkedList<char> content = Utils.GetLinkedList(input);
+        Lexer lexer = new(input);
+        List<SemanticToken> tokens = lexer.Tokenize();
 
-        Assert.True(KeywordSemanticToken.TryParse(0, 0, content.First!,
-            out KeywordSemanticToken? token));
-        Assert.NotNull(token);
-        Assert.Equal(type, token.KeywordType);
+        SemanticToken token = tokens[0];
+        Assert.Equal(SemanticTokenType.Keyword, token.TokenType);
+        KeywordSemanticToken keywordSemanticToken = (KeywordSemanticToken)token;
+        Assert.Equal(type, keywordSemanticToken.KeywordType);
     }
 }
diff --git a/Canon.Tests/LexicalParserTests/NumberTests.cs b/Canon.Tests/LexicalParserTests/NumberTests.cs
index eb2bd94..f2d7d0f 100644
--- a/Canon.Tests/LexicalParserTests/NumberTests.cs
+++ b/Canon.Tests/LexicalParserTests/NumberTests.cs
@@ -25,21 +25,22 @@ namespace Canon.Tests.LexicalParserTests
         [InlineData("1E", 0, NumberType.Real, false)]
         [InlineData("abc", 0, NumberType.Integer, false)]
         [InlineData("123abc", 123, NumberType.Integer, true)]
-        public void TestParseNumber(string input, double expected, NumberType expectedNumberType, bool expectedResult = true)
+        public void TestParseNumber(string input, double expected, NumberType expectedNumberType,
+            bool expectedResult = true)
         {
-            LinkedList<char> content = Utils.GetLinkedList(input);
-            Assert.Equal(expectedResult, NumberSemanticToken.TryParse(0, 0, content.First!,
-                out NumberSemanticToken? token));
-            if (expectedResult)
+            Lexer lexer = new(input);
+            List<SemanticToken> tokens = lexer.Tokenize();
+
+            SemanticToken token = tokens[0];
+            if (!expectedResult)
             {
-                Assert.NotNull(token);
-                Assert.Equal(expected, token.Value);
-                Assert.Equal(expectedNumberType, token.NumberType);
-            }
-            else
-            {
-                Assert.Null(token);
+                Assert.NotEqual(SemanticTokenType.Keyword, token.TokenType);
+                return;
             }
+            Assert.Equal(SemanticTokenType.Number, token.TokenType);
+            NumberSemanticToken numberSemanticToken = (NumberSemanticToken)token;
+            Assert.Equal(expectedNumberType, numberSemanticToken.NumberType);
+            Assert.Equal(expected, numberSemanticToken.Value);
         }
     }
 }
diff --git a/Canon.Tests/LexicalParserTests/OperatorTypeTests.cs b/Canon.Tests/LexicalParserTests/OperatorTypeTests.cs
index 7c37117..b90a2c3 100644
--- a/Canon.Tests/LexicalParserTests/OperatorTypeTests.cs
+++ b/Canon.Tests/LexicalParserTests/OperatorTypeTests.cs
@@ -7,9 +7,7 @@ public class OperatorTypeTests
 {
     [Theory]
     [InlineData("+ 123", OperatorType.Plus)]
-    [InlineData("1 + 123", OperatorType.Plus)]
     [InlineData("+123", OperatorType.Plus)]
-    [InlineData("m +123", OperatorType.Plus)]
     [InlineData("-123", OperatorType.Minus)]
     [InlineData("*123", OperatorType.Multiply)]
     [InlineData("/123", OperatorType.Divide)]
@@ -22,20 +20,24 @@ public class OperatorTypeTests
     [InlineData(":=123", OperatorType.Assign)]
     public void ParseTest(string input, OperatorType result)
     {
-        LinkedList<char> content = Utils.GetLinkedList(input);
-        Assert.True(OperatorSemanticToken.TryParse(0, 0,
-            content.First!, out OperatorSemanticToken? token));
-        Assert.Equal(result, token?.OperatorType);
+        Lexer lexer = new(input);
+        List<SemanticToken> tokens = lexer.Tokenize();
+
+        SemanticToken token = tokens[0];
+        Assert.Equal(SemanticTokenType.Operator, token.TokenType);
+        OperatorSemanticToken operatorSemanticToken = (OperatorSemanticToken)token;
+        Assert.Equal(result, operatorSemanticToken.OperatorType);
     }
 
     [Theory]
-    [InlineData("<><123")]
-    [InlineData("<=<123")]
+    [InlineData("1 + 123")]
+    [InlineData("m +123")]
     public void ParseFailedTest(string input)
     {
-        LinkedList<char> content = Utils.GetLinkedList(input);
-        Assert.False(OperatorSemanticToken.TryParse(0, 0,
-            content.First!, out OperatorSemanticToken? token));
-        Assert.Null(token);
+        Lexer lexer = new(input);
+        List<SemanticToken> tokens = lexer.Tokenize();
+
+        SemanticToken token = tokens[0];
+        Assert.NotEqual(SemanticTokenType.Operator, token.TokenType);
     }
 }