StringOp.hh

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#ifndef STRINGOP_HH
#define STRINGOP_HH
 
#include "IterableBitSet.hh"
#include "likely.hh"
#include "stringsp.hh"
#include <algorithm>
#include <charconv>
#include <cstdint>
#include <iomanip>
#include <limits>
#include <optional>
#include <sstream>
#include <string>
#include <string_view>
#include <type_traits>
#include <utility>
#if defined(__APPLE__)
#include <CoreFoundation/CoreFoundation.h>
#endif
 
namespace StringOp
{
        template<typename T> [[nodiscard]] std::optional<T> stringTo(std::string_view s);
 
        template<int BASE, typename T> [[nodiscard]] std::optional<T> stringToBase(std::string_view s);
 
        [[nodiscard]] bool stringToBool(std::string_view str);
 
        //[[nodiscard]] std::string toLower(std::string_view str);
 
        void trimRight(std::string& str, const char* chars);
        void trimRight(std::string& str, char chars);
        void trimRight(std::string_view& str, std::string_view chars);
        void trimRight(std::string_view& str, char chars);
        void trimLeft (std::string& str, const char* chars);
        void trimLeft (std::string& str, char chars);
        void trimLeft (std::string_view& str, std::string_view chars);
        void trimLeft (std::string_view& str, char chars);
        void trim     (std::string_view& str, std::string_view chars);
        void trim     (std::string_view& str, char chars);
 
        [[nodiscard]] std::pair<std::string_view, std::string_view> splitOnFirst(
                std::string_view str, std::string_view chars);
        [[nodiscard]] std::pair<std::string_view, std::string_view> splitOnFirst(
                std::string_view str, char chars);
        [[nodiscard]] std::pair<std::string_view, std::string_view> splitOnLast(
                std::string_view str, std::string_view chars);
        [[nodiscard]] std::pair<std::string_view, std::string_view> splitOnLast(
                std::string_view str, char chars);
        [[nodiscard]] IterableBitSet<64> parseRange(std::string_view str,
                                                    unsigned min, unsigned max);
 
        //[[nodiscard]] std::vector<std::string_view> split(std::string_view str, char chars);
 
        [[nodiscard]] inline auto split_view(std::string_view str, char c) {
                struct Sentinel {};
 
                struct Iterator {
                        std::string_view str;
                        std::string_view::size_type p;
                        const char c;
 
                        Iterator(std::string_view str_, char c_)
                                : str(str_), c(c_) {
                                next_p();
                        }
 
                        [[nodiscard]] std::string_view operator*() const {
                                return std::string_view(str.data(), p);
                        }
 
                        Iterator& operator++() {
                                if (p < str.size()) {
                                        str.remove_prefix(p + 1);
                                        next_p();
                                } else {
                                        str = "";
                                }
                                return *this;
                        }
 
                        [[nodiscard]] bool operator==(Sentinel) const { return  str.empty(); }
                        [[nodiscard]] bool operator!=(Sentinel) const { return !str.empty(); }
 
                        void next_p() {
                                p = 0;
                                while ((p < str.size()) && (str[p] != c)) ++p;
                        }
                };
 
                struct Splitter {
                        std::string_view str;
                        char c;
 
                        [[nodiscard]] auto begin() const { return Iterator{str, c}; }
                        [[nodiscard]] auto end()   const { return Sentinel{}; }
                };
 
                return Splitter{str, c};
        }
 
        // case insensitive less-than operator
        struct caseless {
                [[nodiscard]] bool operator()(std::string_view s1, std::string_view s2) const {
                        auto m = std::min(s1.size(), s2.size());
                        int r = strncasecmp(s1.data(), s2.data(), m);
                        return (r != 0) ? (r < 0) : (s1.size() < s2.size());
                }
        };
        struct casecmp {
                [[nodiscard]] bool operator()(std::string_view s1, std::string_view s2) const {
                        if (s1.size() != s2.size()) return false;
                        return strncasecmp(s1.data(), s2.data(), s1.size()) == 0;
                }
        };
 
#if defined(__APPLE__)
        [[nodiscard]] std::string fromCFString(CFStringRef str);
#endif
 
        template<int BASE, typename T>
        [[nodiscard]] std::optional<T> stringToBase(std::string_view s)
        {
                T result;
                auto b = s.data();
                auto e = s.data() + s.size();
                if (auto [p, ec] = std::from_chars(b, e, result, BASE);
                    (ec == std::errc()) && (p == e)) {
                        return result;
                }
                return std::nullopt;
        }
 
        template<typename T>
        [[nodiscard]] std::optional<T> stringTo(std::string_view s)
        {
                if (unlikely(s.empty())) return {};
                if constexpr (std::is_signed_v<T>) {
                        bool negate = false;
                        if (unlikely(s[0] == '-')) {
                                negate = true;
                                s.remove_prefix(1);
                        }
 
                        using U = std::make_unsigned_t<T>;
                        auto tmp = stringTo<U>(s);
                        if (unlikely(!tmp)) return {};
 
                        U max = U(std::numeric_limits<T>::max()) + 1; // 0x8000
                        if (unlikely(negate)) {
                                if (unlikely(*tmp > max)) return {}; // 0x8000
                                return T(~*tmp + 1);
                        } else {
                                if (unlikely(*tmp >= max)) return {}; // 0x7fff
                                return T(*tmp);
                        }
                } else {
                        if (likely(s[0] != '0')) {
                                return stringToBase<10, T>(s);
                        } else {
                                if (s.size() == 1) return T(0);
                                if (likely((s[1] == 'x') || (s[1] == 'X'))) {
                                        s.remove_prefix(2);
                                        return stringToBase<16, T>(s);
                                } else if ((s[1] == 'b') || (s[1] == 'B')) {
                                        s.remove_prefix(2);
                                        return stringToBase<2, T>(s);
                                } else {
                                        return stringToBase<10, T>(s);
                                }
                        }
                }
        }
}
 
#endif