Fix bugs and add new statement

- Add clear call stack (`ccs`) statement
- Use `\v` instead of `\r` to support escape sequences in the future

YesNt.Interpreter/Runtime/YesNtInterpreter.cs

@@ -87,7 +87,7 @@ namespace YesNt.Interpreter.Runtime
             staticStatements = staticStatements.OrderBy(s => s.Key.Priority).ToList();
 
             runtimeInfo.OnDebugOutput += (s) => OnDebugOutput?.Invoke(s);
-            runtimeInfo.OnLineExecuted += (DebugEventArgs e) => OnLineExecuted.Invoke(e);
+            runtimeInfo.OnLineExecuted += (DebugEventArgs e) => OnLineExecuted?.Invoke(e);
         }
 
         public void Execute(string path, bool isDebugMode = false)
@@ -138,6 +138,11 @@ namespace YesNt.Interpreter.Runtime
 
                 runtimeInfo.CurrentLine = runtimeInfo.Lines[runtimeInfo.LineNumber].Content.TrimEnd().Replace("\r", string.Empty);
 
+                if (string.IsNullOrWhiteSpace(runtimeInfo.CurrentLine) || runtimeInfo.CurrentLine.StartsWith('#'))
+                {
+                    continue;
+                }
+
                 DebugEventArgs debugEventArgs = new DebugEventArgs()
                 {
                     LineNumber = runtimeInfo.LineNumber + 1,
@@ -146,11 +151,6 @@ namespace YesNt.Interpreter.Runtime
                     TaskId = runtimeInfo.TaskId
                 };
 
-                if (string.IsNullOrWhiteSpace(runtimeInfo.CurrentLine) || runtimeInfo.CurrentLine.StartsWith('#'))
-                {
-                    continue;
-                }
-
                 foreach (KeyValuePair<StaticStatementAttribute, Action> staticStatement in staticStatements)
                 {
                     StaticStatementAttribute staticStatementAttribute = staticStatement.Key;

YesNt.Interpreter/Statements/FunctionStatements.cs

@@ -190,5 +190,11 @@ namespace YesNt.Interpreter.Statements
                 RuntimeInfo.Exit("No function in stack", true);
             }
         }
+
+        [Statement("ccs", SearchMode.Exact, SpaceAround.None, ConsoleColor.Red)]
+        public void ClearCallStack(string _)
+        {
+            RuntimeInfo.FunctionCallStack.Clear();
+        }
     }
 }

YesNt.Interpreter/Utilities/StringExtentions.cs

@@ -11,14 +11,14 @@ namespace YesNt.Interpreter.Utilities
             StringBuilder output = new StringBuilder();
             foreach (char c in input)
             {
-                output.Append($"\r{c}\r");
+                output.Append($"\v{c}\v");
             }
             return output.ToString();
         }
 
         public static string FromSaveString(this string input)
         {
-            return input.Replace("\r", "");
+            return input.Replace("\v", "");
         }
 
         public static bool ToStandardizedNumber(this string input, out double result)