Function gbnf_escape_char_class

common/peg-parser.cpp:1460–1508

}

static std::string gbnf_escape_char_class(uint32_t c) {
    if (c == '-' || c == ']' || c == '[' || c == '\\') {
        return "\\" + std::string(1, (char) c);
    }
    // Escape whitespace control characters
    if (c == '\n') {
        return "\\n";
    }
    if (c == '\t') {
        return "\\t";
    }
    if (c == '\r') {
        return "\\r";
    }

    // Printable ASCII
    if (c >= 0x20 && c <= 0x7E) {
        return std::string(1, (char) c);
    }

    // Hex escape
    char         buf[16];
    const char * hex = "0123456789ABCDEF";

    if (c <= 0xFF) {
        buf[0] = '\\';
        buf[1] = 'x';
        buf[2] = hex[(c >> 4) & 0xF];
        buf[3] = hex[c & 0xF];
        buf[4] = '\0';
    } else if (c <= 0xFFFF) {
        buf[0] = '\\';
        buf[1] = 'u';
        buf[2] = hex[(c >> 12) & 0xF];
        buf[3] = hex[(c >> 8) & 0xF];
        buf[4] = hex[(c >> 4) & 0xF];
        buf[5] = hex[c & 0xF];
        buf[6] = '\0';
    } else {
        buf[0] = '\\';
        buf[1] = 'U';
        for (int i = 0; i < 8; i++) {
            buf[2 + i] = hex[(c >> ((7 - i) * 4)) & 0xF];
        }
        buf[10] = '\0';
    }

    return std::string(buf);
}

static std::string gbnf_excluding_pattern(const std::vector<std::string> & strings) {
    trie matcher(strings);