Fix minor issues with CSConsole delimiter logic

Author: sinai-dev

src/UI/CSConsole/CSAutoCompleter.cs

@@ -41,7 +41,7 @@ public void CheckAutocompletes()
             suggestions.Clear();
 
             int caret = Math.Max(0, Math.Min(InputField.Text.Length - 1, InputField.Component.caretPosition - 1));
-            int start = caret;
+            int startIdx = caret;
 
             // If the character at the caret index is whitespace or delimiter,
             // or if the next character (if it exists) is not whitespace,
@@ -55,17 +55,20 @@ public void CheckAutocompletes()
             }
 
             // get the current composition string (from caret back to last delimiter)
-            while (start > 0)
+            while (startIdx > 0)
             {
-                start--;
-                char c = InputField.Text[start];
+                startIdx--;
+                char c = InputField.Text[startIdx];
                 if (delimiters.Contains(c))
                 {
-                    start++;
+                    startIdx++;
+                    while (char.IsWhiteSpace(InputField.Text[startIdx]))
+                        startIdx++;
                     break;
                 }
             }
-            string input = InputField.Text.Substring(start, caret - start + 1);
+            string input = InputField.Text.Substring(startIdx, caret - startIdx + 1);
+
 
             // Get MCS completions
 

src/UI/CSConsole/Lexers/KeywordLexer.cs

@@ -41,6 +41,10 @@ public override bool TryMatchCurrent(LexerBuilder lexer)
                 while (!lexer.EndOfInput && char.IsLetter(lexer.PeekNext()))
                     sb.Append(lexer.Current);
 
+                // next must be whitespace or delimiter
+                if (!lexer.EndOfInput && !(char.IsWhiteSpace(lexer.Current) || lexer.IsDelimiter(lexer.Current)))
+                    return false;
+
                 if (keywords.Contains(sb.ToString()))
                 {
                     if (!lexer.EndOfInput)

src/UI/CSConsole/Lexers/SymbolLexer.cs

@@ -11,7 +11,7 @@ public class SymbolLexer : Lexer
         protected override Color HighlightColor => new Color(0.6f, 0.6f, 0.6f);
 
         // all symbols are delimiters
-        public override IEnumerable<char> Delimiters => symbols;
+        public override IEnumerable<char> Delimiters => symbols.Where(it => it != '.'); // '.' is not a delimiter, only a separator.
 
         public static bool IsSymbol(char c) => symbols.Contains(c);