string parseString() {
                auto str = appender!string();
        Next:

                switch(peekChar()) {
                case '"':
                        getChar();
                        break;
                case '\\':
                        getChar();
                        auto c = getChar();
                        switch(c) {
                        case '"':       str.put('"');   break;
                        case '\\':      str.put('\\');  break;
                        case '/':       str.put('/');   break;
                        case 'b':       str.put('\b');  break;
                        case 'f':       str.put('\f');  break;
                        case 'n':       str.put('\n');  break;
                        case 'r':       str.put('\r');  break;
                        case 't':       str.put('\t');  break;
                        case 'u':
                                dchar val = 0;
                                foreach_reverse(i; 0 .. 4) {
                                        auto hex = toupper(getChar());
                                        if(!isxdigit(hex)) error("Expecting hex character");
                                        val += (isdigit(hex) ? hex - '0' : hex - 'A') << (4 * i);
                                }
                                char[4] buf = void;
                                str.put(toUTF8(buf, val)); // *****error here
                                break;
                        default:
                                error(text("Invalid escape sequence '\\", c, "'."));
                        }
                        goto Next;
                default:
                        auto c = getChar();
                        appendJSONChar(&str, c, &error);
                        goto Next;
                }
                return str.data;
        }