C-style relational operators

Added support for C-style relational operators: == , !=, >=, <=.
Fixed save as to cpd for cpdz files.
Fixed input fields counting in code.
Fixed resetting input fields to zero after editing the source code.
Html select input is replaced with text in output only if class "post" is added.

Calcpad.Wpf/HighLighter.cs

@@ -275,18 +275,17 @@ internal void Parse(Paragraph p, bool isComplex, int line)
             if (p is null)
                 return;
 
+            if (p.Tag is Queue<string> queue)
+                _values = queue;
+            else
+                GetValues(p);
+
             var text = InitParagraph(p);
             InitState(p, text, line);
             _tagHelper = new();
             LocalVariables.Clear();
             _hasTargetUnitsDelimiter = false;
             _allowUnaryMinus = true;
-
-            if (_state.Paragraph.Tag is Queue<string> queue)
-                _values = queue;
-            else
-                GetValues(_state.Paragraph);
-
             _builder.Clear();
             for (int i = 0, len = text.Length; i < len; ++i)
             {
@@ -748,8 +747,25 @@ private void Append(Types t)
                 return;
 
             var s = _builder.ToString();
-            string sourceCode = string.Empty;
             _builder.Clear();
+            var count = _state.Paragraph.Inlines.Count;
+            if (s == "=" && count > 0)
+            {
+                Run r = (Run)_state.Paragraph.Inlines.LastInline;
+                var runText = r.Text;
+                if (runText == " = " || runText == "!" || runText == " > " || runText == " < ")
+                {
+                    r.Text = runText switch
+                    {
+                        " = " => " ≡ ",
+                        "!" => " ≠ ",
+                        " > " => " ≥ ",
+                        _ => " ≤ "
+                    };
+                    return;
+                }
+            }
+            string sourceCode = string.Empty;
             if (t == Types.Include)
             {
                 var sourceFlieName = s.Trim();

Calcpad.Wpf/MainWindow.xaml.cs

@@ -735,15 +735,16 @@ private void RecentFileList_Click(object sender, RoutedEventArgs e)
             if (File.Exists(fileName))
                 FileOpen(fileName);
         }
-
+        
         private void Command_SaveAs(object sender, ExecutedRoutedEventArgs e) => FileSaveAs();
 
         private void FileSaveAs()
         {
             string s;
-            if (string.IsNullOrWhiteSpace(CurrentFileName))
+            var count = CountInputFields(InputText);
+            if (!string.IsNullOrWhiteSpace(CurrentFileName))
                 s = Path.GetExtension(CurrentFileName);
-            else if (InputText.Contains('?', StringComparison.Ordinal))
+            else if (count > 0)
                 s = ".cpd";
             else
                 s = ".txt";
@@ -2128,8 +2129,7 @@ private void RichTextBox_SelectionChanged(object sender, RoutedEventArgs e)
                 return;
 
             var p = tps.Paragraph;
-            if (p is null)
-                p = tpe.Paragraph;
+            p ??= tpe.Paragraph;
 
             if (!ReferenceEquals(_currentParagraph, tps.Paragraph) &&
                 !ReferenceEquals(_currentParagraph, tpe.Paragraph))
@@ -2576,8 +2576,7 @@ private void HighLightPastedText()
             RichTextBox.BeginChange();
             var p = _pasteEnd.Paragraph;
             _currentParagraph = RichTextBox.Selection.Start.Paragraph;
-            if (p is null)
-                p = (Paragraph)_document.Blocks.FirstBlock;
+            p ??= (Paragraph)_document.Blocks.FirstBlock;
 
             var lineNumber = GetLineNumber(p);
             while (p != _currentParagraph)
@@ -2765,8 +2764,7 @@ private void Include_Click(object sender, MouseButtonEventArgs e)
                     if (tt is not null)
                         tt.Visibility = Visibility.Hidden;
                     var process = RunExternalApp("NOTEPAD++", fileName);
-                    if (process is null)
-                        process = RunExternalApp("NOTEPAD", fileName);
+                    process ??= RunExternalApp("NOTEPAD", fileName);
                     if (tt is not null)
                         tt.Visibility = Visibility.Visible;
                     if (process is not null)
@@ -2847,7 +2845,9 @@ private static int CountInputFields(string s)
             char commentChar = nullChar;
             foreach (var c in s)
             {
-                if (c == '\'' || c == '"')
+                if (c == '\n')
+                    commentChar = nullChar;
+                else if (c == '\'' || c == '"')
                 {
                     if (commentChar == nullChar)
                         commentChar = c;