private bool IsTriggerChar(char currentChar, char previousChar, bool isVisible)
        {
            bool result = false;

            if ((char.IsLetter(currentChar) || (isVisible && char.IsLetterOrDigit(currentChar))) || languageService.CanTriggerIntellisense(currentChar, previousChar))
            {
                result = true;
            }

            return(result);
        }