MongoDB.Bson.IO.JsonScanner.GetUnquotedStringToken C# (CSharp) Метод

        private static JsonToken GetUnquotedStringToken(JsonBuffer buffer)
        {
            // opening letter or $ has already been read
            var start = buffer.Position - 1;
            var c = buffer.Read();
            while (c == '$' || c == '_' || char.IsLetterOrDigit((char)c))
            {
                c = buffer.Read();
            }
            buffer.UnRead(c);
            var lexeme = buffer.Substring(start, buffer.Position - start);
            return new StringJsonToken(JsonTokenType.UnquotedString, lexeme, lexeme);
        }