UnityEngine.TextEditor.ClassifyChar C# (CSharp) Method

        private CharacterType ClassifyChar(char c)
        {
            if (char.IsWhiteSpace(c))
            {
                return CharacterType.WhiteSpace;
            }
            if (char.IsLetterOrDigit(c) || (c == '\''))
            {
                return CharacterType.LetterLike;
            }
            return CharacterType.Symbol;
        }