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#include "./filtered_string_view.h"
namespace fsv {
// Iterator implementation.
auto filtered_string_view::begin() const noexcept -> iterator {
// Our iterator might have to be incremented so that it's pointing to
// the first valid.
auto it = iterator{this->string, this->length, this->pred, this->string};
if (not std::invoke(this->pred, *it)) {
++it;
}
return it;
}
auto filtered_string_view::end() const noexcept -> iterator {
return iterator{this->string, this->length, this->pred, this->string + this->length};
}
auto filtered_string_view::cbegin() const noexcept -> const_iterator {
return std::begin(*this);
}
auto filtered_string_view::cend() const noexcept -> const_iterator {
return std::end(*this);
}
auto filtered_string_view::rbegin() const noexcept -> reverse_iterator {
return std::reverse_iterator<iterator>(std::end(*this));
}
auto filtered_string_view::rend() const noexcept -> reverse_iterator {
return std::reverse_iterator<iterator>(std::begin(*this));
}
auto filtered_string_view::crbegin() const noexcept -> const_reverse_iterator {
return std::rbegin(*this);
}
auto filtered_string_view::crend() const noexcept -> const_reverse_iterator {
return std::rend(*this);
}
filtered_string_view::iterator::iterator(const value_type* const& str,
const std::size_t& len,
const filter& pred,
const value_type* const& i) noexcept
: string(str)
, length(&len)
, predicate(&pred)
, it(i) {}
auto filtered_string_view::iterator::operator*() const noexcept -> reference {
return *this->it;
}
auto filtered_string_view::iterator::operator->() const noexcept -> reference {
return this->operator*();
}
auto filtered_string_view::iterator::operator++() noexcept -> iterator& {
do {
++this->it;
if (not std::invoke(*this->predicate, *this->it)) {
continue;
}
break;
} while (this->it != this->string + *this->length);
return *this;
}
auto filtered_string_view::iterator::operator++(int) noexcept -> iterator {
iterator ret = *this;
++(*this);
return ret;
}
auto filtered_string_view::iterator::operator--() noexcept -> iterator& {
do {
--this->it;
if (not std::invoke(*this->predicate, *this->it)) {
continue;
}
break;
} while (this->it != this->string);
return *this;
}
auto filtered_string_view::iterator::operator--(int) noexcept -> iterator {
iterator ret = *this;
--(*this);
return ret;
}
auto operator==(const filtered_string_view::iterator& a, const filtered_string_view::iterator& b) noexcept -> bool {
return a.it == b.it;
}
auto operator!=(const filtered_string_view::iterator& a, const filtered_string_view::iterator& b) noexcept -> bool {
return not(a == b);
}
// Class methods implementation.
filtered_string_view::filtered_string_view() noexcept
: string(nullptr)
, length(0)
, pred(default_predicate) {}
filtered_string_view::filtered_string_view(const std::string& str) noexcept
: string(std::data(str))
, length(std::size(str))
, pred(default_predicate) {}
filtered_string_view::filtered_string_view(const std::string& str, filter pred) noexcept
: string(std::data(str))
, length(std::size(str))
, pred(pred) {}
filtered_string_view::filtered_string_view(const char* str) noexcept
: string(str)
, length(std::strlen(str))
, pred(default_predicate) {}
filtered_string_view::filtered_string_view(const char* str, filter pred) noexcept
: string(str)
, length(std::strlen(str))
, pred(pred) {}
filtered_string_view::filtered_string_view(const filtered_string_view& other) noexcept
: string(other.string)
, length(other.length)
, pred(other.pred) {}
filtered_string_view::filtered_string_view(filtered_string_view&& other) noexcept
: string(std::exchange(other.string, nullptr))
, length(std::exchange(other.length, 0))
, pred(std::exchange(other.pred, default_predicate)) {}
auto filtered_string_view::operator=(const filtered_string_view& other) noexcept -> filtered_string_view& {
if (&other != this) { // self-copied object should remain unchanged.
this->string = other.string;
this->length = other.length;
this->pred = other.pred;
}
return *this;
}
auto filtered_string_view::operator=(filtered_string_view&& other) noexcept -> filtered_string_view& {
if (&other != this) { // self-copied object should remain unchanged.
this->string = std::exchange(other.string, nullptr);
this->length = std::exchange(other.length, 0);
this->pred = std::exchange(other.pred, default_predicate);
}
return *this;
}
auto filtered_string_view::operator[](const std::size_t& n) const noexcept -> const char& {
return *std::next(std::begin(*this), n);
}
auto filtered_string_view::operator[](const int& n) const noexcept -> const char& {
return (*this)[static_cast<std::size_t>(n)];
}
filtered_string_view::operator std::string() const {
auto result = std::string{};
std::copy(std::begin(*this), std::end(*this), std::back_inserter(result));
return result;
}
auto filtered_string_view::at(const int index) const -> const char& {
const auto throw_index = [&]() {
throw std::domain_error("filtered_string_view::at(" + std::to_string(index) + "): invalid index");
};
if (index < 0) {
throw_index();
}
auto it = std::begin(*this);
for (auto i = 0; i < index; ++i) {
++it;
if (it == std::end(*this)) {
throw_index();
}
}
return *it;
}
auto filtered_string_view::size() const noexcept -> std::size_t {
return std::distance(std::begin(*this), std::end(*this));
}
auto filtered_string_view::empty() const noexcept -> bool {
return std::size(*this) == 0;
}
auto filtered_string_view::data() const noexcept -> const char* {
return this->string;
}
auto filtered_string_view::predicate() const noexcept -> const filter& {
return this->pred;
}
auto operator==(const filtered_string_view& a, const filtered_string_view& b) -> bool {
return std::string{a} == std::string{b};
}
auto operator<=>(const filtered_string_view& a, const filtered_string_view& b) -> std::strong_ordering {
return std::string{a} <=> std::string{b};
}
auto operator<<(std::ostream& os, const filtered_string_view& fsv) -> std::ostream& {
os << std::string{fsv};
return os;
}
auto filtered_string_view::default_predicate(const char&) noexcept -> bool {
return true;
}
auto compose(const filtered_string_view& fsv, const std::vector<filter>& filts) -> filtered_string_view {
return filtered_string_view{std::data(fsv), [&](const auto& c) {
return std::all_of(std::begin(filts), std::end(filts), [&](const auto& func) {
return std::invoke(func, c);
});
}};
}
auto split(const filtered_string_view& fsv, const filtered_string_view& tok) -> std::vector<filtered_string_view> {
std::vector<filtered_string_view> result{};
const auto origin = std::string{fsv};
const auto target = std::string{tok};
const auto skip = std::size(target);
for (auto a = 0ul, b = origin.find(target, a); a != std::string::npos; a = b + skip, b = origin.find(target, a))
{
if (b == std::string::npos) {
result.push_back(fsv::substr(fsv, static_cast<int>(a)));
break;
}
if (a == b) {
result.push_back("");
continue;
}
result.push_back(fsv::substr(fsv, static_cast<int>(a), static_cast<int>(b - a)));
}
return result;
}
auto substr(const filtered_string_view& fsv, const int pos, const int count) -> filtered_string_view {
const auto predicate = fsv.predicate();
const auto rcount = count <= 0 ? static_cast<int>(std::size(fsv)) - pos : count;
if (rcount == 0 or std::begin(fsv) == std::end(fsv)) {
return filtered_string_view{};
}
const auto start =
std::next(std::begin(fsv), static_cast<fsv::filtered_string_view::iterator::difference_type>(pos));
if (start == std::end(fsv)) {
return filtered_string_view{};
}
const auto end = std::next(start, static_cast<fsv::filtered_string_view::iterator::difference_type>(rcount - 1));
return filtered_string_view{std::data(fsv), [=](const auto& c) {
if (not std::invoke(predicate, c)) {
return false;
}
return &c >= &*start and &c <= &*end;
}};
} // namespace fsv
} // namespace fsv
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