// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the License for the
// specific language governing permissions and limitations
// under the License.
#pragma once
#include <cassert>
#include <optional>
#include <string>
#include <string_view>
#include <type_traits>
#include <utility>
#include <vector>
#if __has_include(<charconv>)
# include <charconv>
#endif
#include "arrow/result.h"
#include "arrow/util/visibility.h"
namespace arrow {
class Status;
ARROW_EXPORT std::string HexEncode(const uint8_t* data, size_t length);
ARROW_EXPORT std::string Escape(const char* data, size_t length);
ARROW_EXPORT std::string HexEncode(const char* data, size_t length);
ARROW_EXPORT std::string HexEncode(std::string_view str);
ARROW_EXPORT std::string Escape(std::string_view str);
ARROW_EXPORT Status ParseHexValue(const char* hex_pair, uint8_t* out);
ARROW_EXPORT Status ParseHexValues(std::string_view hex_string, uint8_t* out);
namespace internal {
/// Like std::string_view::starts_with in C++20
inline bool StartsWith(std::string_view s, std::string_view prefix) {
return s.length() >= prefix.length() &&
(s.empty() || s.substr(0, prefix.length()) == prefix);
}
/// Like std::string_view::ends_with in C++20
inline bool EndsWith(std::string_view s, std::string_view suffix) {
return s.length() >= suffix.length() &&
(s.empty() || s.substr(s.length() - suffix.length()) == suffix);
}
/// \brief Split a string with a delimiter
ARROW_EXPORT
std::vector<std::string_view> SplitString(std::string_view v, char delim,
int64_t limit = 0);
/// \brief Join strings with a delimiter
ARROW_EXPORT
std::string JoinStrings(const std::vector<std::string_view>& strings,
std::string_view delimiter);
/// \brief Join strings with a delimiter
ARROW_EXPORT
std::string JoinStrings(const std::vector<std::string>& strings,
std::string_view delimiter);
/// \brief Trim whitespace from left and right sides of string
ARROW_EXPORT
std::string TrimString(std::string value);
ARROW_EXPORT
bool AsciiEqualsCaseInsensitive(std::string_view left, std::string_view right);
ARROW_EXPORT
std::string AsciiToLower(std::string_view value);
ARROW_EXPORT
std::string AsciiToUpper(std::string_view value);
/// \brief Search for the first instance of a token and replace it or return nullopt if
/// the token is not found.
ARROW_EXPORT
std::optional<std::string> Replace(std::string_view s, std::string_view token,
std::string_view replacement);
/// \brief Get boolean value from string
///
/// If "1", "true" (case-insensitive), returns true
/// If "0", "false" (case-insensitive), returns false
/// Otherwise, returns Status::Invalid
ARROW_EXPORT
arrow::Result<bool> ParseBoolean(std::string_view value);
#if __has_include(<charconv>)
namespace detail {
template <typename T, typename = void>
struct can_to_chars : public std::false_type {};
template <typename T>
struct can_to_chars<
T, std::void_t<decltype(std::to_chars(std::declval<char*>(), std::declval<char*>(),
std::declval<std::remove_reference_t<T>>()))>>
: public std::true_type {};
} // namespace detail
/// \brief Whether std::to_chars exists for the current value type.
///
/// This is useful as some C++ libraries do not implement all specified overloads
/// for std::to_chars.
template <typename T>
inline constexpr bool have_to_chars = detail::can_to_chars<T>::value;
/// \brief An ergonomic wrapper around std::to_chars, returning a std::string
///
/// For most inputs, the std::string result will not incur any heap allocation
/// thanks to small string optimization.
///
/// Compared to std::to_string, this function gives locale-agnostic results
/// and might also be faster.
template <typename T, typename... Args>
std::string ToChars(T value, Args&&... args) {
if constexpr (!have_to_chars<T>) {
// Some C++ standard libraries do not yet implement std::to_chars for all types,
// in which case we have to fallback to std::string.
return std::to_string(value);
} else {
// According to various sources, the GNU libstdc++ and Microsoft's C++ STL
// allow up to 15 bytes of small string optimization, while clang's libc++
// goes up to 22 bytes. Choose the pessimistic value.
std::string out(15, 0);
auto res = std::to_chars(&out.front(), &out.back(), value, args...);
while (res.ec != std::errc{}) {
assert(res.ec == std::errc::value_too_large);
out.resize(out.capacity() * 2);
res = std::to_chars(&out.front(), &out.back(), value, args...);
}
const auto length = res.ptr - out.data();
assert(length <= static_cast<int64_t>(out.length()));
out.resize(length);
return out;
}
}
#else // !__has_include(<charconv>)
template <typename T>
inline constexpr bool have_to_chars = false;
template <typename T, typename... Args>
std::string ToChars(T value, Args&&... args) {
return std::to_string(value);
}
#endif
} // namespace internal
} // namespace arrow