static const int priorities[] = {50 /*Mention*/,

50 /*Hashtag*/,

50 /*BotCommand*/,

50 /*Url*/,

50 /*EmailAddress*/,

90 /*Bold*/,

91 /*Italic*/,

20 /*Code*/,

11 /*Pre*/,

10 /*PreCode*/,

49 /*TextUrl*/,

49 /*MentionName*/,

50 /*Cashtag*/,

50 /*PhoneNumber*/,

92 /*Underline*/,

93 /*Strikethrough*/,

0 /*BlockQuote*/,

50 /*BankCardNumber*/,

50 /*MediaTimestamp*/,

94 /*Spoiler*/,

99 /*CustomEmoji*/,

0 /*ExpandableBlockQuote*/};

static_assert(sizeof(priorities) / sizeof(priorities[0]) == static_cast<size_t>(MessageEntity::Type::Size), "");

return priorities[static_cast<int32>(type)];

const UserManager *user_manager) const {

switch (type) {

case MessageEntity::Type::Mention:

return make_tl_object<td_api::textEntityTypeMention>();

case MessageEntity::Type::Hashtag:

return make_tl_object<td_api::textEntityTypeHashtag>();

case MessageEntity::Type::BotCommand:

return make_tl_object<td_api::textEntityTypeBotCommand>();

case MessageEntity::Type::Url:

return make_tl_object<td_api::textEntityTypeUrl>();

case MessageEntity::Type::EmailAddress:

return make_tl_object<td_api::textEntityTypeEmailAddress>();

case MessageEntity::Type::Bold:

return make_tl_object<td_api::textEntityTypeBold>();

case MessageEntity::Type::Italic:

return make_tl_object<td_api::textEntityTypeItalic>();

case MessageEntity::Type::Underline:

return make_tl_object<td_api::textEntityTypeUnderline>();

case MessageEntity::Type::Strikethrough:

return make_tl_object<td_api::textEntityTypeStrikethrough>();

case MessageEntity::Type::BlockQuote:

return make_tl_object<td_api::textEntityTypeBlockQuote>();

case MessageEntity::Type::Code:

return make_tl_object<td_api::textEntityTypeCode>();

case MessageEntity::Type::Pre:

return make_tl_object<td_api::textEntityTypePre>();

case MessageEntity::Type::PreCode:

return make_tl_object<td_api::textEntityTypePreCode>(argument);

case MessageEntity::Type::TextUrl:

return make_tl_object<td_api::textEntityTypeTextUrl>(argument);

case MessageEntity::Type::MentionName:

return make_tl_object<td_api::textEntityTypeMentionName>(

user_manager == nullptr ? user_id.get()

: user_manager->get_user_id_object(user_id, "textEntityTypeMentionName"));

case MessageEntity::Type::Cashtag:

return make_tl_object<td_api::textEntityTypeCashtag>();

case MessageEntity::Type::PhoneNumber:

return make_tl_object<td_api::textEntityTypePhoneNumber>();

case MessageEntity::Type::BankCardNumber:

return make_tl_object<td_api::textEntityTypeBankCardNumber>();

case MessageEntity::Type::MediaTimestamp:

return make_tl_object<td_api::textEntityTypeMediaTimestamp>(media_timestamp);

case MessageEntity::Type::Spoiler:

return make_tl_object<td_api::textEntityTypeSpoiler>();

case MessageEntity::Type::CustomEmoji:

return make_tl_object<td_api::textEntityTypeCustomEmoji>(custom_emoji_id.get());

case MessageEntity::Type::ExpandableBlockQuote:

return make_tl_object<td_api::textEntityTypeExpandableBlockQuote>();

default:

UNREACHABLE();

return nullptr;

}

const vector<MessageEntity> &entities,

bool skip_bot_commands, int32 max_media_timestamp) {

vector<tl_object_ptr<td_api::textEntity>> result;

result.reserve(entities.size());

for (auto &entity : entities) {

if (skip_bot_commands && entity.type == MessageEntity::Type::BotCommand) {

continue;

}

if (entity.type == MessageEntity::Type::MediaTimestamp && max_media_timestamp < entity.media_timestamp) {

continue;

}

auto entity_object = entity.get_text_entity_object(user_manager);

if (entity_object->type_ != nullptr) {

result.push_back(std::move(entity_object));

}

}

return result;

const FormattedText &text, bool skip_bot_commands,

int32 max_media_timestamp) {

return td_api::make_object<td_api::formattedText>(

text.text, get_text_entities_object(user_manager, text.entities, skip_bot_commands, max_media_timestamp));

switch (get_unicode_simple_category(code)) {

case UnicodeSimpleCategory::Letter:

case UnicodeSimpleCategory::DecimalNumber:

case UnicodeSimpleCategory::Number:

return true;

default:

return code == '_';

}

vector<Slice> result;

const unsigned char *begin = str.ubegin();

const unsigned char *end = str.uend();

const unsigned char *ptr = begin;

// '/(?<=\B)@([a-zA-Z0-9_]{2,32})(?=\b)/u'

while (true) {

ptr = static_cast<const unsigned char *>(std::memchr(ptr, '@', narrow_cast<int32>(end - ptr)));

if (ptr == nullptr) {

break;

}

if (ptr != begin) {

uint32 prev;

next_utf8_unsafe(prev_utf8_unsafe(ptr), &prev);

if (is_word_character(prev)) {

ptr++;

continue;

}

}

auto mention_begin = ++ptr;

while (ptr != end && is_alpha_digit_or_underscore(*ptr)) {

ptr++;

}

auto mention_end = ptr;

auto mention_size = mention_end - mention_begin;

if (mention_size < 2 || mention_size > 32) {

continue;

}

uint32 next = 0;

if (ptr != end) {

next_utf8_unsafe(ptr, &next);

}

if (is_word_character(next)) {

continue;

}

result.emplace_back(mention_begin - 1, mention_end);

}

return result;

vector<Slice> result;

const unsigned char *begin = str.ubegin();

const unsigned char *end = str.uend();

const unsigned char *ptr = begin;

// '/(?<!\b|[\/<>])\/([a-zA-Z0-9_]{1,64})(?:@([a-zA-Z0-9_]{3,32}))?(?!\B|[\/<>])/u'

while (true) {

ptr = static_cast<const unsigned char *>(std::memchr(ptr, '/', narrow_cast<int32>(end - ptr)));

if (ptr == nullptr) {

break;

}

if (ptr != begin) {

uint32 prev;

next_utf8_unsafe(prev_utf8_unsafe(ptr), &prev);

if (is_word_character(prev) || prev == '/' || prev == '<' || prev == '>') {

ptr++;

continue;

}

}

auto command_begin = ++ptr;

while (ptr != end && is_alpha_digit_or_underscore(*ptr)) {

ptr++;

}

auto command_end = ptr;

auto command_size = command_end - command_begin;

if (command_size < 1 || command_size > 64) {

continue;

}

if (ptr != end && *ptr == '@') {

auto mention_begin = ++ptr;

while (ptr != end && is_alpha_digit_or_underscore(*ptr)) {

ptr++;

}

auto mention_end = ptr;

auto mention_size = mention_end - mention_begin;

if (mention_size < 3 || mention_size > 32) {

continue;

}

command_end = ptr;

}

uint32 next = 0;

if (ptr != end) {

next_utf8_unsafe(ptr, &next);

}

if (is_word_character(next) || next == '/' || next == '<' || next == '>') {

continue;

}

result.emplace_back(command_begin - 1, command_end);

}

return result;

category = get_unicode_simple_category(c);

if (c == '_' || c == 0x200c || c == 0xb7 || (0xd80 <= c && c <= 0xdff)) {

return true;

}

switch (category) {

case UnicodeSimpleCategory::DecimalNumber:

case UnicodeSimpleCategory::Letter:

return true;

default:

return false;

}

vector<Slice> result;

const unsigned char *begin = str.ubegin();

const unsigned char *end = str.uend();

const unsigned char *ptr = begin;

// '/(?<=^|[^is_hashtag_letter])#([is_hashtag_letter]{1,256})(?:@([a-zA-Z0-9_]{3,32}))?(?![is_hashtag_letter]*#)/u'

// and at least one letter

UnicodeSimpleCategory category;

while (true) {

ptr = static_cast<const unsigned char *>(std::memchr(ptr, '#', narrow_cast<int32>(end - ptr)));

if (ptr == nullptr) {

break;

}

if (ptr != begin) {

uint32 prev;

next_utf8_unsafe(prev_utf8_unsafe(ptr), &prev);

if (is_hashtag_letter(prev, category)) {

ptr++;

continue;

}

}

auto hashtag_begin = ++ptr;

size_t hashtag_size = 0;

const unsigned char *hashtag_end = nullptr;

bool was_letter = false;

while (ptr != end) {

uint32 code;

auto next_ptr = next_utf8_unsafe(ptr, &code);

if (!is_hashtag_letter(code, category)) {

break;

}

ptr = next_ptr;

if (hashtag_size == 255) {

hashtag_end = ptr;

}

if (hashtag_size != 256) {

was_letter |= category == UnicodeSimpleCategory::Letter;

hashtag_size++;

}

}

if (!hashtag_end) {

hashtag_end = ptr;

}

if (hashtag_size < 1) {

continue;

}

if (hashtag_end == ptr && ptr != end && ptr[0] == '@') {

auto username_end = ptr + 1;

while (username_end != end && username_end - ptr < 33 && is_alpha_digit_or_underscore(*username_end)) {

username_end++;

}

auto length = username_end - ptr - 1;

if (length >= 3) {

ptr = username_end;

hashtag_end = username_end;

}

}

if (ptr != end && ptr[0] == '#') {

continue;

}

if (!was_letter) {

continue;

}

result.emplace_back(hashtag_begin - 1, hashtag_end);

}

return result;

vector<Slice> result;

const unsigned char *begin = str.ubegin();

const unsigned char *end = str.uend();

const unsigned char *ptr = begin;

// '/(?<=^|[^$is_hashtag_letter])\$(1INCH|[A-Z]{1,8})(?:@([a-zA-Z0-9_]{3,32}))?(?![$is_hashtag_letter])/u'

UnicodeSimpleCategory category;

while (true) {

ptr = static_cast<const unsigned char *>(std::memchr(ptr, '$', narrow_cast<int32>(end - ptr)));

if (ptr == nullptr) {

break;

}

if (ptr != begin) {

uint32 prev;

next_utf8_unsafe(prev_utf8_unsafe(ptr), &prev);

if (is_hashtag_letter(prev, category) || prev == '$') {

ptr++;

continue;

}

}

auto cashtag_begin = ++ptr;

if (end - ptr >= 5 && Slice(ptr, ptr + 5) == Slice("1INCH")) {

ptr += 5;

} else {

while (ptr != end && 'Z' >= *ptr && *ptr >= 'A') {

ptr++;

}

}

auto cashtag_end = ptr;

auto cashtag_size = cashtag_end - cashtag_begin;

if (cashtag_size < 1 || cashtag_size > 8) {

continue;

}

if (ptr != end && ptr[0] == '@') {

auto username_end = ptr + 1;

while (username_end != end && is_alpha_digit_or_underscore(*username_end)) {

username_end++;

}

auto length = username_end - ptr - 1;

if (length >= 3 && length <= 32) {

cashtag_end = username_end;

ptr = username_end;

}

}

if (cashtag_end != end) {

uint32 code;

next_utf8_unsafe(ptr, &code);

if (is_hashtag_letter(code, category) || code == '$') {

continue;

}

}

result.emplace_back(cashtag_begin - 1, cashtag_end);

}

return result;

vector<Slice> result;

const unsigned char *begin = str.ubegin();

const unsigned char *end = str.uend();

const unsigned char *ptr = begin;

while (true) {

ptr = static_cast<const unsigned char *>(std::memchr(ptr, ':', narrow_cast<int32>(end - ptr)));

if (ptr == nullptr) {

break;

}

auto media_timestamp_begin = ptr;

while (media_timestamp_begin != begin &&

(media_timestamp_begin[-1] == ':' || is_digit(media_timestamp_begin[-1]))) {

media_timestamp_begin--;

}

auto media_timestamp_end = ptr;

while (media_timestamp_end + 1 != end && (media_timestamp_end[1] == ':' || is_digit(media_timestamp_end[1]))) {

media_timestamp_end++;

}

media_timestamp_end++;

if (media_timestamp_begin != ptr && media_timestamp_end != ptr + 1 && is_digit(ptr[1])) {

ptr = media_timestamp_end;

if (media_timestamp_begin != begin) {

uint32 prev;

next_utf8_unsafe(prev_utf8_unsafe(media_timestamp_begin), &prev);

if (is_word_character(prev)) {

continue;

}

}

if (media_timestamp_end != end) {

uint32 next;

next_utf8_unsafe(media_timestamp_end, &next);

if (is_word_character(next)) {

continue;

}

}

result.emplace_back(media_timestamp_begin, media_timestamp_end);

} else {

ptr = media_timestamp_end;

}

}

return result;

vector<Slice> result;

const unsigned char *begin = str.ubegin();

const unsigned char *end = str.uend();

const unsigned char *ptr = begin;

// '/(?<=^|[^+_\pL\d-.,])[\d -]{13,}([^_\pL\d-]|$)/'

while (true) {

while (ptr != end && !is_digit(*ptr)) {

ptr++;

}

if (ptr == end) {

break;

}

if (ptr != begin) {

uint32 prev;

next_utf8_unsafe(prev_utf8_unsafe(ptr), &prev);

if (prev == '.' || prev == ',' || prev == '+' || prev == '-' || prev == '_' ||

get_unicode_simple_category(prev) == UnicodeSimpleCategory::Letter) {

while (ptr != end && (is_digit(*ptr) || *ptr == ' ' || *ptr == '-')) {

ptr++;

}

continue;

}

}

auto card_number_begin = ptr;

size_t digit_count = 0;

while (ptr != end && (is_digit(*ptr) || *ptr == ' ' || *ptr == '-')) {

if (*ptr == ' ' && digit_count >= 16 && digit_count <= 19 &&

digit_count == static_cast<size_t>(ptr - card_number_begin)) {

// continuous card number

break;

}

digit_count += static_cast<size_t>(is_digit(*ptr));

ptr++;

}

if (digit_count < 13 || digit_count > 19) {

continue;

}

auto card_number_end = ptr;

while (!is_digit(card_number_end[-1])) {

card_number_end--;

}

auto card_number_size = static_cast<size_t>(card_number_end - card_number_begin);

if (card_number_size > 2 * digit_count - 1) {

continue;

}

if (card_number_end != end) {

uint32 next;

next_utf8_unsafe(card_number_end, &next);

if (next == '-' || next == '_' || get_unicode_simple_category(next) == UnicodeSimpleCategory::Letter) {

continue;

}

}

result.emplace_back(card_number_begin, card_number_end);

}

return result;

if (0x2000 <= c && c <= 0x206f) { // General Punctuation

// Zero Width Non-Joiner/Joiner and various dashes

return c == 0x200c || c == 0x200d || (0x2010 <= c && c <= 0x2015);

}

return get_unicode_simple_category(c) != UnicodeSimpleCategory::Separator;

switch (c) {

case '\n':

case '<':

case '>':

case '"':

case 0xab: // «

case 0xbb: // »

return false;

default:

return is_url_unicode_symbol(c);

}

vector<Slice> result;

const unsigned char *begin = str.ubegin();

const unsigned char *end = str.uend();

const unsigned char *ptr = begin;

// '(tg|ton|tonsite)://[a-z0-9_-]{1,253}([/?#][^\s\x{2000}-\x{200b}\x{200e}-\x{200f}\x{2016}-\x{206f}<>«»"]*)?'

Slice bad_path_end_chars(".:;,('?!`");

while (end - ptr > 5) {

ptr = static_cast<const unsigned char *>(std::memchr(ptr, ':', narrow_cast<int32>(end - ptr)));

if (ptr == nullptr) {

break;

}

const unsigned char *url_begin = nullptr;

if (end - ptr >= 3 && ptr[1] == '/' && ptr[2] == '/') {

if (ptr - begin >= 2 && to_lower(ptr[-2]) == 't' && to_lower(ptr[-1]) == 'g') {

url_begin = ptr - 2;

} else if (ptr - begin >= 3 && to_lower(ptr[-3]) == 't' && to_lower(ptr[-2]) == 'o' && to_lower(ptr[-1]) == 'n') {

url_begin = ptr - 3;

} else if (ptr - begin >= 7 && to_lower(ptr[-7]) == 't' && to_lower(ptr[-6]) == 'o' && to_lower(ptr[-5]) == 'n' &&

to_lower(ptr[-4]) == 's' && to_lower(ptr[-3]) == 'i' && to_lower(ptr[-2]) == 't' &&

to_lower(ptr[-1]) == 'e') {

url_begin = ptr - 3;

}

}

if (url_begin == nullptr) {

++ptr;

continue;

}

ptr += 3;

auto domain_begin = ptr;

while (ptr != end && ptr - domain_begin != 253 && is_alpha_digit_or_underscore_or_minus(*ptr)) {

ptr++;

}

if (ptr == domain_begin) {

continue;

}

if (ptr != end && (*ptr == '/' || *ptr == '?' || *ptr == '#')) {

auto path_end_ptr = ptr + 1;

while (path_end_ptr != end) {

uint32 code = 0;

auto next_ptr = next_utf8_unsafe(path_end_ptr, &code);

if (!is_url_path_symbol(code)) {

break;

}

path_end_ptr = next_ptr;

}

while (path_end_ptr > ptr + 1 && bad_path_end_chars.find(path_end_ptr[-1]) < bad_path_end_chars.size()) {

path_end_ptr--;

}

if (ptr[0] == '/' || path_end_ptr > ptr + 1) {

ptr = path_end_ptr;

}

}

result.emplace_back(url_begin, ptr);

}

return result;

vector<Slice> result;

const unsigned char *begin = str.ubegin();

const unsigned char *end = str.uend();

const auto &is_protocol_symbol = [](uint32 c) {

if (c < 0x80) {

// do not allow dots in the protocol

return is_alpha_digit(c) || c == '+' || c == '-';

}

// add unicode letters and digits to later discard protocol as invalid

return get_unicode_simple_category(c) != UnicodeSimpleCategory::Separator;

};

const auto &is_user_data_symbol = [](uint32 c) {

switch (c) {

case '\n':

case '/':

case '[':

case ']':

case '{':

case '}':

case '(':

case ')':

case '\'':

case '`':

case '<':

case '>':

case '"':

case '@':

case 0xab: // «

case 0xbb: // »

return false;

default:

return is_url_unicode_symbol(c);

}

};

const auto &is_domain_symbol = [](uint32 c) {

if (c < 0xc0) {

return c == '.' || is_alpha_digit_or_underscore_or_minus(c) || c == '~';

}

return is_url_unicode_symbol(c);

};

Slice bad_path_end_chars(".:;,('?!`");

while (true) {

auto dot_pos = str.find('.');

if (dot_pos > str.size() || dot_pos + 1 == str.size()) {

break;

}

if (str[dot_pos + 1] == ' ') {

// fast path

str = str.substr(dot_pos + 2);

begin = str.ubegin();

continue;

}

const unsigned char *domain_begin_ptr = begin + dot_pos;

while (domain_begin_ptr != begin) {

domain_begin_ptr = prev_utf8_unsafe(domain_begin_ptr);

uint32 code = 0;

auto next_ptr = next_utf8_unsafe(domain_begin_ptr, &code);

if (!is_domain_symbol(code)) {

domain_begin_ptr = next_ptr;

break;

}

}

const unsigned char *last_at_ptr = nullptr;

const unsigned char *domain_end_ptr = begin + dot_pos;

while (domain_end_ptr != end) {

uint32 code = 0;

auto next_ptr = next_utf8_unsafe(domain_end_ptr, &code);

if (code == '@') {

last_at_ptr = domain_end_ptr;

} else if (!is_domain_symbol(code)) {

break;

}

domain_end_ptr = next_ptr;

}

if (last_at_ptr != nullptr) {

while (domain_begin_ptr != begin) {

domain_begin_ptr = prev_utf8_unsafe(domain_begin_ptr);

uint32 code = 0;

auto next_ptr = next_utf8_unsafe(domain_begin_ptr, &code);

if (!is_user_data_symbol(code)) {

domain_begin_ptr = next_ptr;

break;

}

}

}

// LOG(ERROR) << "Domain: " << Slice(domain_begin_ptr, domain_end_ptr);

const unsigned char *url_end_ptr = domain_end_ptr;

if (url_end_ptr != end && url_end_ptr[0] == ':') {

auto port_end_ptr = url_end_ptr + 1;

while (port_end_ptr != end && is_digit(port_end_ptr[0])) {

port_end_ptr++;

}

auto port_begin_ptr = url_end_ptr + 1;

while (port_begin_ptr != port_end_ptr && *port_begin_ptr == '0') {

port_begin_ptr++;

}

if (port_begin_ptr != port_end_ptr && narrow_cast<int>(port_end_ptr - port_begin_ptr) <= 5 &&

to_integer<uint32>(Slice(port_begin_ptr, port_end_ptr)) <= 65535) {

url_end_ptr = port_end_ptr;

}

}

// LOG(ERROR) << "Domain_port: " << Slice(domain_begin_ptr, url_end_ptr);

if (url_end_ptr != end && (url_end_ptr[0] == '/' || url_end_ptr[0] == '?' || url_end_ptr[0] == '#')) {

auto path_end_ptr = url_end_ptr + 1;

while (path_end_ptr != end) {

uint32 code = 0;

auto next_ptr = next_utf8_unsafe(path_end_ptr, &code);

if (!is_url_path_symbol(code)) {

break;

}

path_end_ptr = next_ptr;

}

while (path_end_ptr > url_end_ptr + 1 && bad_path_end_chars.find(path_end_ptr[-1]) < bad_path_end_chars.size()) {

path_end_ptr--;

}

if (url_end_ptr[0] == '/' || path_end_ptr > url_end_ptr + 1) {

url_end_ptr = path_end_ptr;

}

}

while (url_end_ptr > begin + dot_pos + 1 && url_end_ptr[-1] == '.') {

url_end_ptr--;

}

// LOG(ERROR) << "Domain_port_path: " << Slice(domain_begin_ptr, url_end_ptr);

bool is_bad = false;

const unsigned char *url_begin_ptr = domain_begin_ptr;

if (url_begin_ptr != begin && url_begin_ptr[-1] == '@') {

if (last_at_ptr != nullptr) {

is_bad = true;

}

auto user_data_begin_ptr = url_begin_ptr - 1;

while (user_data_begin_ptr != begin) {

user_data_begin_ptr = prev_utf8_unsafe(user_data_begin_ptr);

uint32 code = 0;

auto next_ptr = next_utf8_unsafe(user_data_begin_ptr, &code);

if (!is_user_data_symbol(code)) {

user_data_begin_ptr = next_ptr;

break;

}

}

if (user_data_begin_ptr == url_begin_ptr - 1) {

is_bad = true;

}

url_begin_ptr = user_data_begin_ptr;

}

// LOG(ERROR) << "User_data_port_path: " << Slice(url_begin_ptr, url_end_ptr);

if (url_begin_ptr != begin) {

Slice prefix(begin, url_begin_ptr);

if (prefix.size() >= 6 && ends_with(prefix, "://")) {

auto protocol_begin_ptr = url_begin_ptr - 3;

while (protocol_begin_ptr != begin) {

protocol_begin_ptr = prev_utf8_unsafe(protocol_begin_ptr);

uint32 code = 0;

auto next_ptr = next_utf8_unsafe(protocol_begin_ptr, &code);

if (!is_protocol_symbol(code)) {

protocol_begin_ptr = next_ptr;

break;

}

}

auto protocol = to_lower(Slice(protocol_begin_ptr, url_begin_ptr - 3));

if (ends_with(protocol, "http") && protocol != "shttp") {

url_begin_ptr = url_begin_ptr - 7;

} else if (ends_with(protocol, "https")) {

url_begin_ptr = url_begin_ptr - 8;

} else if (ends_with(protocol, "ftp") && protocol != "tftp" && protocol != "sftp") {

url_begin_ptr = url_begin_ptr - 6;

} else if (ends_with(protocol, "tonsite")) {

url_begin_ptr = url_begin_ptr - 10;

} else {

is_bad = true;

}

} else {

auto prefix_end = prefix.uend();

auto prefix_back = prev_utf8_unsafe(prefix_end);

uint32 code = 0;

next_utf8_unsafe(prefix_back, &code);

if (is_word_character(code) || code == '/' || code == '#' || code == '@') {

is_bad = true;

}

}

}

// LOG(ERROR) << "Full: " << Slice(url_begin_ptr, url_end_ptr) << " " << is_bad;

if (!is_bad) {

if (url_end_ptr > begin + dot_pos + 1) {

result.emplace_back(url_begin_ptr, url_end_ptr);

}

while (url_end_ptr != end && url_end_ptr[0] == '.') {

url_end_ptr++;

}

} else {

while (url_end_ptr[-1] != '.') {

url_end_ptr--;

}

}

if (url_end_ptr <= begin + dot_pos) {

url_end_ptr = begin + dot_pos + 1;

}

str = str.substr(url_end_ptr - begin);

begin = url_end_ptr;

}

return result;

const size_t MIN_CARD_LENGTH = 13;

const size_t MAX_CARD_LENGTH = 19;

char digits[MAX_CARD_LENGTH];

size_t digit_count = 0;

for (auto c : str) {

if (is_digit(c)) {

CHECK(digit_count < MAX_CARD_LENGTH);

digits[digit_count++] = c;

}

}

CHECK(digit_count >= MIN_CARD_LENGTH);

// Luhn algorithm

int32 sum = 0;

for (size_t i = digit_count; i > 0; i--) {

int32 digit = digits[i - 1] - '0';

if ((digit_count - i) % 2 == 0) {

sum += digit;

} else {

sum += (digit < 5 ? 2 * digit : 2 * digit - 9);

}

}

if (sum % 10 != 0) {

return false;

}

int32 prefix1 = (digits[0] - '0');

int32 prefix2 = prefix1 * 10 + (digits[1] - '0');

int32 prefix3 = prefix2 * 10 + (digits[2] - '0');

int32 prefix4 = prefix3 * 10 + (digits[3] - '0');

if (prefix1 == 4) {

// Visa

return digit_count == 13 || digit_count == 16 || digit_count == 18 || digit_count == 19;

}

if ((51 <= prefix2 && prefix2 <= 55) || (2221 <= prefix4 && prefix4 <= 2720)) {

// mastercard

return digit_count == 16;

}

if (prefix2 == 34 || prefix2 == 37) {

// American Express

return digit_count == 15;

}

if (prefix2 == 62 || prefix2 == 81) {

// UnionPay

return digit_count >= 16;

}

if (2200 <= prefix4 && prefix4 <= 2204) {

// MIR

return digit_count == 16;

}

return true; // skip length check

// /^([a-z0-9_-]{0,26}[.+]){0,10}[a-z0-9_-]{1,35}@(([a-z0-9][a-z0-9_-]{0,28})?[a-z0-9][.]){1,6}[a-z]{2,8}$/i

Slice userdata;

Slice domain;

std::tie(userdata, domain) = split(str, '@');

if (domain.empty()) {

return false;

}

size_t prev = 0;

size_t userdata_part_count = 0;

for (size_t i = 0; i < userdata.size(); i++) {

if (userdata[i] == '.' || userdata[i] == '+') {