Function EscapeC

library/cpp/yson/writer.cpp:45–89

        const size_t ESCAPE_C_BUFFER_SIZE = 4;

        inline size_t EscapeC(unsigned char c, char next, char r[ESCAPE_C_BUFFER_SIZE]) {
            // (1) Printable characters go as-is, except backslash and double quote.
            // (2) Characters \r, \n, \t and \0 ... \7 replaced by their simple escape characters (if possible).
            // (3) Otherwise, character is encoded using hexadecimal escape sequence (if possible), or octal.
            if (c == '\"') {
                r[0] = '\\';
                r[1] = '\"';
                return 2;
            } else if (c == '\\') {
                r[0] = '\\';
                r[1] = '\\';
                return 2;
            } else if (IsPrintable(c)) {
                r[0] = c;
                return 1;
            } else if (c == '\r') {
                r[0] = '\\';
                r[1] = 'r';
                return 2;
            } else if (c == '\n') {
                r[0] = '\\';
                r[1] = 'n';
                return 2;
            } else if (c == '\t') {
                r[0] = '\\';
                r[1] = 't';
                return 2;
            } else if (c < 8 && !IsOctDigit(next)) {
                r[0] = '\\';
                r[1] = OctDigit(c);
                return 2;
            } else if (!IsHexDigit(next)) {
                r[0] = '\\';
                r[1] = 'x';
                r[2] = HexDigit((c & 0xF0) >> 4);
                r[3] = HexDigit((c & 0x0F) >> 0);
                return 4;
            } else {
                r[0] = '\\';
                r[1] = OctDigit((c & 0700) >> 6);
                r[2] = OctDigit((c & 0070) >> 3);
                r[3] = OctDigit((c & 0007) >> 0);
                return 4;
            }
        }

        void EscapeC(const char* str, size_t len, IOutputStream& output) {
            char buffer[ESCAPE_C_BUFFER_SIZE];