add: exceptions(#7)

Reviewed-on: PostGuard/Canon#7
Co-authored-by: Lan_G <2911328695@qq.com>
Co-committed-by: Lan_G <2911328695@qq.com>

Canon.Core/Exceptions/GrammarException.cs

@@ -0,0 +1,12 @@
+namespace Canon.Core.Exceptions;
+/// <summary>
+/// 语法分析中引发的异常
+/// </summary>
+public class GrammarException : Exception
+{
+    public GrammarException()  { }
+
+    public GrammarException(string message) : base(message) { }
+
+    public GrammarException(string message, Exception innerException) : base(message, innerException) { }
+}

Canon.Core/Exceptions/LexemeException.cs

@@ -0,0 +1,25 @@
+namespace Canon.Core.Exceptions;
+/// <summary>
+/// 词法分析中引发的异常
+/// </summary>
+public class LexemeException : Exception
+{
+    public LexemeException()  { }
+
+    public LexemeException(string message) : base(message) { }
+
+    public LexemeException(string message, Exception innerException) :
+        base(message, innerException) { }
+
+    /// <param name="line">单词的行号</param>
+    /// <param name="charPosition">单词的列号</param>
+    /// <param name="message">错误信息</param>
+    public LexemeException(uint line, uint charPosition, string message) :
+        base("line:" + line + ", charPosition:" + charPosition + " :" + message) { }
+
+    public LexemeException(uint line, uint charPosition, Exception innerException) :
+        base("line:" + line + ", charPosition:" + charPosition + " : ", innerException) { }
+
+    public LexemeException(uint line, uint charPosition, string message, Exception innerException) :
+        base("line:" + line + ", charPosition:" + charPosition + " :" + message, innerException) { }
+}

Canon.Core/Exceptions/SemanticException.cs

@@ -0,0 +1,12 @@
+namespace Canon.Core.Exceptions;
+/// <summary>
+/// 语义分析中引发的异常
+/// </summary>
+public class SemanticException : Exception
+{
+    public SemanticException() : base() { }
+
+    public SemanticException(string message) : base(message) { }
+
+    public SemanticException(string message, Exception innerException) : base(message, innerException) { }
+}