/** * @file cpptoml.h * @author Chase Geigle * @date May 2013 */ #ifndef _CPPTOML_H_ #define _CPPTOML_H_ #include #include #include #include #include #include #include #include #include #include #include #include #include #if __cplusplus > 201103L #define CPPTOML_DEPRECATED(reason) [[deprecated(reason)]] #elif defined(__clang__) #define CPPTOML_DEPRECATED(reason) __attribute__((deprecated(reason))) #elif defined(__GNUG__) #define CPPTOML_DEPRECATED(reason) __attribute__((deprecated)) #elif defined(_MSC_VER) #if _MSC_VER < 1910 #define CPPTOML_DEPRECATED(reason) __declspec(deprecated) #else #define CPPTOML_DEPRECATED(reason) [[deprecated(reason)]] #endif #endif namespace cpptoml { class writer; // forward declaration class base; // forward declaration #if defined(CPPTOML_USE_MAP) // a std::map will ensure that entries a sorted, albeit at a slight // performance penalty relative to the (default) unordered_map using string_to_base_map = std::map>; #else // by default an unordered_map is used for best performance as the // toml specification does not require entries to be sorted using string_to_base_map = std::unordered_map>; #endif template class option { public: option() : empty_{true} { // nothing } option(T value) : empty_{false}, value_{std::move(value)} { // nothing } explicit operator bool() const { return !empty_; } const T& operator*() const { return value_; } const T* operator->() const { return &value_; } const T& value_or(const T& alternative) const { if (!empty_) return value_; return alternative; } private: bool empty_; T value_; }; struct local_date { int year = 0; int month = 0; int day = 0; }; struct local_time { int hour = 0; int minute = 0; int second = 0; int microsecond = 0; }; struct zone_offset { int hour_offset = 0; int minute_offset = 0; }; struct local_datetime : local_date, local_time { }; struct offset_datetime : local_datetime, zone_offset { static inline struct offset_datetime from_zoned(const struct tm& t) { offset_datetime dt; dt.year = t.tm_year + 1900; dt.month = t.tm_mon + 1; dt.day = t.tm_mday; dt.hour = t.tm_hour; dt.minute = t.tm_min; dt.second = t.tm_sec; char buf[16]; strftime(buf, 16, "%z", &t); int offset = std::stoi(buf); dt.hour_offset = offset / 100; dt.minute_offset = offset % 100; return dt; } CPPTOML_DEPRECATED("from_local has been renamed to from_zoned") static inline struct offset_datetime from_local(const struct tm& t) { return from_zoned(t); } static inline struct offset_datetime from_utc(const struct tm& t) { offset_datetime dt; dt.year = t.tm_year + 1900; dt.month = t.tm_mon + 1; dt.day = t.tm_mday; dt.hour = t.tm_hour; dt.minute = t.tm_min; dt.second = t.tm_sec; return dt; } }; CPPTOML_DEPRECATED("datetime has been renamed to offset_datetime") typedef offset_datetime datetime; class fill_guard { public: fill_guard(std::ostream& os) : os_(os), fill_{os.fill()} { // nothing } ~fill_guard() { os_.fill(fill_); } private: std::ostream& os_; std::ostream::char_type fill_; }; inline std::ostream& operator<<(std::ostream& os, const local_date& dt) { fill_guard g{os}; os.fill('0'); using std::setw; os << setw(4) << dt.year << "-" << setw(2) << dt.month << "-" << setw(2) << dt.day; return os; } inline std::ostream& operator<<(std::ostream& os, const local_time& ltime) { fill_guard g{os}; os.fill('0'); using std::setw; os << setw(2) << ltime.hour << ":" << setw(2) << ltime.minute << ":" << setw(2) << ltime.second; if (ltime.microsecond > 0) { os << "."; int power = 100000; for (int curr_us = ltime.microsecond; curr_us; power /= 10) { auto num = curr_us / power; os << num; curr_us -= num * power; } } return os; } inline std::ostream& operator<<(std::ostream& os, const zone_offset& zo) { fill_guard g{os}; os.fill('0'); using std::setw; if (zo.hour_offset != 0 || zo.minute_offset != 0) { if (zo.hour_offset > 0) { os << "+"; } else { os << "-"; } os << setw(2) << std::abs(zo.hour_offset) << ":" << setw(2) << std::abs(zo.minute_offset); } else { os << "Z"; } return os; } inline std::ostream& operator<<(std::ostream& os, const local_datetime& dt) { return os << static_cast(dt) << "T" << static_cast(dt); } inline std::ostream& operator<<(std::ostream& os, const offset_datetime& dt) { return os << static_cast(dt) << static_cast(dt); } template struct is_one_of; template struct is_one_of : std::is_same { }; template struct is_one_of { const static bool value = std::is_same::value || is_one_of::value; }; template class value; template struct valid_value : is_one_of { }; template struct value_traits; template struct valid_value_or_string_convertible { const static bool value = valid_value::type>::value || std::is_convertible::value; }; template struct value_traits:: value>::type> { using value_type = typename std:: conditional::type>::value, typename std::decay::type, std::string>::type; using type = value; static value_type construct(T&& val) { return value_type(val); } }; template struct value_traits::value && std::is_floating_point< typename std::decay::type>::value>:: type> { using value_type = typename std::decay::type; using type = value; static value_type construct(T&& val) { return value_type(val); } }; template struct value_traits::value && std::is_signed:: type>::value>::type> { using value_type = int64_t; using type = value; static value_type construct(T&& val) { if (val < std::numeric_limits::min()) throw std::underflow_error{"constructed value cannot be " "represented by a 64-bit signed " "integer"}; if (val > std::numeric_limits::max()) throw std::overflow_error{"constructed value cannot be represented " "by a 64-bit signed integer"}; return static_cast(val); } }; template struct value_traits::value && std::is_unsigned:: type>::value>::type> { using value_type = int64_t; using type = value; static value_type construct(T&& val) { if (val > static_cast(std::numeric_limits::max())) throw std::overflow_error{"constructed value cannot be represented " "by a 64-bit signed integer"}; return static_cast(val); } }; class array; class table; class table_array; template struct array_of_trait { using return_type = option>; }; template <> struct array_of_trait { using return_type = option>>; }; template inline std::shared_ptr::type> make_value(T&& val); inline std::shared_ptr make_array(); template inline std::shared_ptr make_element(); inline std::shared_ptr make_table(); inline std::shared_ptr make_table_array(); /** * A generic base TOML value used for type erasure. */ class base : public std::enable_shared_from_this { public: virtual ~base() = default; virtual std::shared_ptr clone() const = 0; /** * Determines if the given TOML element is a value. */ virtual bool is_value() const { return false; } /** * Determines if the given TOML element is a table. */ virtual bool is_table() const { return false; } /** * Converts the TOML element into a table. */ std::shared_ptr
as_table() { if (is_table()) return std::static_pointer_cast
(shared_from_this()); return nullptr; } /** * Determines if the TOML element is an array of "leaf" elements. */ virtual bool is_array() const { return false; } /** * Converts the TOML element to an array. */ std::shared_ptr as_array() { if (is_array()) return std::static_pointer_cast(shared_from_this()); return nullptr; } /** * Determines if the given TOML element is an array of tables. */ virtual bool is_table_array() const { return false; } /** * Converts the TOML element into a table array. */ std::shared_ptr as_table_array() { if (is_table_array()) return std::static_pointer_cast(shared_from_this()); return nullptr; } /** * Attempts to coerce the TOML element into a concrete TOML value * of type T. */ template std::shared_ptr> as(); template std::shared_ptr> as() const; template void accept(Visitor&& visitor, Args&&... args) const; protected: base() { // nothing } }; /** * A concrete TOML value representing the "leaves" of the "tree". */ template class value : public base { struct make_shared_enabler { // nothing; this is a private key accessible only to friends }; template friend std::shared_ptr::type> cpptoml::make_value(U&& val); public: static_assert(valid_value::value, "invalid value type"); std::shared_ptr clone() const override; value(const make_shared_enabler&, const T& val) : value(val) { // nothing; note that users cannot actually invoke this function // because they lack access to the make_shared_enabler. } bool is_value() const override { return true; } /** * Gets the data associated with this value. */ T& get() { return data_; } /** * Gets the data associated with this value. Const version. */ const T& get() const { return data_; } private: T data_; /** * Constructs a value from the given data. */ value(const T& val) : data_(val) { } value(const value& val) = delete; value& operator=(const value& val) = delete; }; template std::shared_ptr::type> make_value(T&& val) { using value_type = typename value_traits::type; using enabler = typename value_type::make_shared_enabler; return std::make_shared( enabler{}, value_traits::construct(std::forward(val))); } template inline std::shared_ptr> base::as() { return std::dynamic_pointer_cast>(shared_from_this()); } // special case value to allow getting an integer parameter as a // double value template <> inline std::shared_ptr> base::as() { if (auto v = std::dynamic_pointer_cast>(shared_from_this())) return v; if (auto v = std::dynamic_pointer_cast>(shared_from_this())) return make_value(static_cast(v->get())); return nullptr; } template inline std::shared_ptr> base::as() const { return std::dynamic_pointer_cast>(shared_from_this()); } // special case value to allow getting an integer parameter as a // double value template <> inline std::shared_ptr> base::as() const { if (auto v = std::dynamic_pointer_cast>(shared_from_this())) return v; if (auto v = as()) { // the below has to be a non-const value due to a bug in // libc++: https://llvm.org/bugs/show_bug.cgi?id=18843 return make_value(static_cast(v->get())); } return nullptr; } /** * Exception class for array insertion errors. */ class array_exception : public std::runtime_error { public: array_exception(const std::string& err) : std::runtime_error{err} { } }; class array : public base { public: friend std::shared_ptr make_array(); std::shared_ptr clone() const override; virtual bool is_array() const override { return true; } using size_type = std::size_t; /** * arrays can be iterated over */ using iterator = std::vector>::iterator; /** * arrays can be iterated over. Const version. */ using const_iterator = std::vector>::const_iterator; iterator begin() { return values_.begin(); } const_iterator begin() const { return values_.begin(); } iterator end() { return values_.end(); } const_iterator end() const { return values_.end(); } /** * Obtains the array (vector) of base values. */ std::vector>& get() { return values_; } /** * Obtains the array (vector) of base values. Const version. */ const std::vector>& get() const { return values_; } std::shared_ptr at(size_t idx) const { return values_.at(idx); } /** * Obtains an array of values. Note that elements may be * nullptr if they cannot be converted to a value. */ template std::vector>> array_of() const { std::vector>> result(values_.size()); std::transform(values_.begin(), values_.end(), result.begin(), [&](std::shared_ptr v) { return v->as(); }); return result; } /** * Obtains a option>. The option will be empty if the array * contains values that are not of type T. */ template inline typename array_of_trait::return_type get_array_of() const { std::vector result; result.reserve(values_.size()); for (const auto& val : values_) { if (auto v = val->as()) result.push_back(v->get()); else return {}; } return {std::move(result)}; } /** * Obtains an array of arrays. Note that elements may be nullptr * if they cannot be converted to a array. */ std::vector> nested_array() const { std::vector> result(values_.size()); std::transform(values_.begin(), values_.end(), result.begin(), [&](std::shared_ptr v) -> std::shared_ptr { if (v->is_array()) return std::static_pointer_cast(v); return std::shared_ptr{}; }); return result; } /** * Add a value to the end of the array */ template void push_back(const std::shared_ptr>& val) { if (values_.empty() || values_[0]->as()) { values_.push_back(val); } else { throw array_exception{"Arrays must be homogenous."}; } } /** * Add an array to the end of the array */ void push_back(const std::shared_ptr& val) { if (values_.empty() || values_[0]->is_array()) { values_.push_back(val); } else { throw array_exception{"Arrays must be homogenous."}; } } /** * Convenience function for adding a simple element to the end * of the array. */ template void push_back(T&& val, typename value_traits::type* = 0) { push_back(make_value(std::forward(val))); } /** * Insert a value into the array */ template iterator insert(iterator position, const std::shared_ptr>& value) { if (values_.empty() || values_[0]->as()) { return values_.insert(position, value); } else { throw array_exception{"Arrays must be homogenous."}; } } /** * Insert an array into the array */ iterator insert(iterator position, const std::shared_ptr& value) { if (values_.empty() || values_[0]->is_array()) { return values_.insert(position, value); } else { throw array_exception{"Arrays must be homogenous."}; } } /** * Convenience function for inserting a simple element in the array */ template iterator insert(iterator position, T&& val, typename value_traits::type* = 0) { return insert(position, make_value(std::forward(val))); } /** * Erase an element from the array */ iterator erase(iterator position) { return values_.erase(position); } /** * Clear the array */ void clear() { values_.clear(); } /** * Reserve space for n values. */ void reserve(size_type n) { values_.reserve(n); } private: array() = default; template array(InputIterator begin, InputIterator end) : values_{begin, end} { // nothing } array(const array& obj) = delete; array& operator=(const array& obj) = delete; std::vector> values_; }; inline std::shared_ptr make_array() { struct make_shared_enabler : public array { make_shared_enabler() { // nothing } }; return std::make_shared(); } template <> inline std::shared_ptr make_element() { return make_array(); } /** * Obtains a option>. The option will be empty if the array * contains values that are not of type T. */ template <> inline typename array_of_trait::return_type array::get_array_of() const { std::vector> result; result.reserve(values_.size()); for (const auto& val : values_) { if (auto v = val->as_array()) result.push_back(v); else return {}; } return {std::move(result)}; } class table; class table_array : public base { friend class table; friend std::shared_ptr make_table_array(); public: std::shared_ptr clone() const override; using size_type = std::size_t; /** * arrays can be iterated over */ using iterator = std::vector>::iterator; /** * arrays can be iterated over. Const version. */ using const_iterator = std::vector>::const_iterator; iterator begin() { return array_.begin(); } const_iterator begin() const { return array_.begin(); } iterator end() { return array_.end(); } const_iterator end() const { return array_.end(); } virtual bool is_table_array() const override { return true; } std::vector>& get() { return array_; } const std::vector>& get() const { return array_; } /** * Add a table to the end of the array */ void push_back(const std::shared_ptr
& val) { array_.push_back(val); } /** * Insert a table into the array */ iterator insert(iterator position, const std::shared_ptr
& value) { return array_.insert(position, value); } /** * Erase an element from the array */ iterator erase(iterator position) { return array_.erase(position); } /** * Clear the array */ void clear() { array_.clear(); } /** * Reserve space for n tables. */ void reserve(size_type n) { array_.reserve(n); } private: table_array() { // nothing } table_array(const table_array& obj) = delete; table_array& operator=(const table_array& rhs) = delete; std::vector> array_; }; inline std::shared_ptr make_table_array() { struct make_shared_enabler : public table_array { make_shared_enabler() { // nothing } }; return std::make_shared(); } template <> inline std::shared_ptr make_element() { return make_table_array(); } // The below are overloads for fetching specific value types out of a value // where special casting behavior (like bounds checking) is desired template typename std::enable_if::value && std::is_signed::value, option>::type get_impl(const std::shared_ptr& elem) { if (auto v = elem->as()) { if (v->get() < std::numeric_limits::min()) throw std::underflow_error{ "T cannot represent the value requested in get"}; if (v->get() > std::numeric_limits::max()) throw std::overflow_error{ "T cannot represent the value requested in get"}; return {static_cast(v->get())}; } else { return {}; } } template typename std::enable_if::value && std::is_unsigned::value, option>::type get_impl(const std::shared_ptr& elem) { if (auto v = elem->as()) { if (v->get() < 0) throw std::underflow_error{"T cannot store negative value in get"}; if (static_cast(v->get()) > std::numeric_limits::max()) throw std::overflow_error{ "T cannot represent the value requested in get"}; return {static_cast(v->get())}; } else { return {}; } } template typename std::enable_if::value || std::is_same::value, option>::type get_impl(const std::shared_ptr& elem) { if (auto v = elem->as()) { return {v->get()}; } else { return {}; } } /** * Represents a TOML keytable. */ class table : public base { public: friend class table_array; friend std::shared_ptr
make_table(); std::shared_ptr clone() const override; /** * tables can be iterated over. */ using iterator = string_to_base_map::iterator; /** * tables can be iterated over. Const version. */ using const_iterator = string_to_base_map::const_iterator; iterator begin() { return map_.begin(); } const_iterator begin() const { return map_.begin(); } iterator end() { return map_.end(); } const_iterator end() const { return map_.end(); } bool is_table() const override { return true; } bool empty() const { return map_.empty(); } /** * Determines if this key table contains the given key. */ bool contains(const std::string& key) const { return map_.find(key) != map_.end(); } /** * Determines if this key table contains the given key. Will * resolve "qualified keys". Qualified keys are the full access * path separated with dots like "grandparent.parent.child". */ bool contains_qualified(const std::string& key) const { return resolve_qualified(key); } /** * Obtains the base for a given key. * @throw std::out_of_range if the key does not exist */ std::shared_ptr get(const std::string& key) const { return map_.at(key); } /** * Obtains the base for a given key. Will resolve "qualified * keys". Qualified keys are the full access path separated with * dots like "grandparent.parent.child". * * @throw std::out_of_range if the key does not exist */ std::shared_ptr get_qualified(const std::string& key) const { std::shared_ptr p; resolve_qualified(key, &p); return p; } /** * Obtains a table for a given key, if possible. */ std::shared_ptr
get_table(const std::string& key) const { if (contains(key) && get(key)->is_table()) return std::static_pointer_cast
(get(key)); return nullptr; } /** * Obtains a table for a given key, if possible. Will resolve * "qualified keys". */ std::shared_ptr
get_table_qualified(const std::string& key) const { if (contains_qualified(key) && get_qualified(key)->is_table()) return std::static_pointer_cast
(get_qualified(key)); return nullptr; } /** * Obtains an array for a given key. */ std::shared_ptr get_array(const std::string& key) const { if (!contains(key)) return nullptr; return get(key)->as_array(); } /** * Obtains an array for a given key. Will resolve "qualified keys". */ std::shared_ptr get_array_qualified(const std::string& key) const { if (!contains_qualified(key)) return nullptr; return get_qualified(key)->as_array(); } /** * Obtains a table_array for a given key, if possible. */ std::shared_ptr get_table_array(const std::string& key) const { if (!contains(key)) return nullptr; return get(key)->as_table_array(); } /** * Obtains a table_array for a given key, if possible. Will resolve * "qualified keys". */ std::shared_ptr get_table_array_qualified(const std::string& key) const { if (!contains_qualified(key)) return nullptr; return get_qualified(key)->as_table_array(); } /** * Helper function that attempts to get a value corresponding * to the template parameter from a given key. */ template option get_as(const std::string& key) const { try { return get_impl(get(key)); } catch (const std::out_of_range&) { return {}; } } /** * Helper function that attempts to get a value corresponding * to the template parameter from a given key. Will resolve "qualified * keys". */ template option get_qualified_as(const std::string& key) const { try { return get_impl(get_qualified(key)); } catch (const std::out_of_range&) { return {}; } } /** * Helper function that attempts to get an array of values of a given * type corresponding to the template parameter for a given key. * * If the key doesn't exist, doesn't exist as an array type, or one or * more keys inside the array type are not of type T, an empty option * is returned. Otherwise, an option containing a vector of the values * is returned. */ template inline typename array_of_trait::return_type get_array_of(const std::string& key) const { if (auto v = get_array(key)) { std::vector result; result.reserve(v->get().size()); for (const auto& b : v->get()) { if (auto val = b->as()) result.push_back(val->get()); else return {}; } return {std::move(result)}; } return {}; } /** * Helper function that attempts to get an array of values of a given * type corresponding to the template parameter for a given key. Will * resolve "qualified keys". * * If the key doesn't exist, doesn't exist as an array type, or one or * more keys inside the array type are not of type T, an empty option * is returned. Otherwise, an option containing a vector of the values * is returned. */ template inline typename array_of_trait::return_type get_qualified_array_of(const std::string& key) const { if (auto v = get_array_qualified(key)) { std::vector result; result.reserve(v->get().size()); for (const auto& b : v->get()) { if (auto val = b->as()) result.push_back(val->get()); else return {}; } return {std::move(result)}; } return {}; } /** * Adds an element to the keytable. */ void insert(const std::string& key, const std::shared_ptr& value) { map_[key] = value; } /** * Convenience shorthand for adding a simple element to the * keytable. */ template void insert(const std::string& key, T&& val, typename value_traits::type* = 0) { insert(key, make_value(std::forward(val))); } /** * Removes an element from the table. */ void erase(const std::string& key) { map_.erase(key); } private: table() { // nothing } table(const table& obj) = delete; table& operator=(const table& rhs) = delete; std::vector split(const std::string& value, char separator) const { std::vector result; std::string::size_type p = 0; std::string::size_type q; while ((q = value.find(separator, p)) != std::string::npos) { result.emplace_back(value, p, q - p); p = q + 1; } result.emplace_back(value, p); return result; } // If output parameter p is specified, fill it with the pointer to the // specified entry and throw std::out_of_range if it couldn't be found. // // Otherwise, just return true if the entry could be found or false // otherwise and do not throw. bool resolve_qualified(const std::string& key, std::shared_ptr* p = nullptr) const { auto parts = split(key, '.'); auto last_key = parts.back(); parts.pop_back(); auto table = this; for (const auto& part : parts) { table = table->get_table(part).get(); if (!table) { if (!p) return false; throw std::out_of_range{key + " is not a valid key"}; } } if (!p) return table->map_.count(last_key) != 0; *p = table->map_.at(last_key); return true; } string_to_base_map map_; }; /** * Helper function that attempts to get an array of arrays for a given * key. * * If the key doesn't exist, doesn't exist as an array type, or one or * more keys inside the array type are not of type T, an empty option * is returned. Otherwise, an option containing a vector of the values * is returned. */ template <> inline typename array_of_trait::return_type table::get_array_of(const std::string& key) const { if (auto v = get_array(key)) { std::vector> result; result.reserve(v->get().size()); for (const auto& b : v->get()) { if (auto val = b->as_array()) result.push_back(val); else return {}; } return {std::move(result)}; } return {}; } /** * Helper function that attempts to get an array of arrays for a given * key. Will resolve "qualified keys". * * If the key doesn't exist, doesn't exist as an array type, or one or * more keys inside the array type are not of type T, an empty option * is returned. Otherwise, an option containing a vector of the values * is returned. */ template <> inline typename array_of_trait::return_type table::get_qualified_array_of(const std::string& key) const { if (auto v = get_array_qualified(key)) { std::vector> result; result.reserve(v->get().size()); for (const auto& b : v->get()) { if (auto val = b->as_array()) result.push_back(val); else return {}; } return {std::move(result)}; } return {}; } std::shared_ptr
make_table() { struct make_shared_enabler : public table { make_shared_enabler() { // nothing } }; return std::make_shared(); } template <> inline std::shared_ptr
make_element
() { return make_table(); } template std::shared_ptr value::clone() const { return make_value(data_); } inline std::shared_ptr array::clone() const { auto result = make_array(); result->reserve(values_.size()); for (const auto& ptr : values_) result->values_.push_back(ptr->clone()); return result; } inline std::shared_ptr table_array::clone() const { auto result = make_table_array(); result->reserve(array_.size()); for (const auto& ptr : array_) result->array_.push_back(ptr->clone()->as_table()); return result; } inline std::shared_ptr table::clone() const { auto result = make_table(); for (const auto& pr : map_) result->insert(pr.first, pr.second->clone()); return result; } /** * Exception class for all TOML parsing errors. */ class parse_exception : public std::runtime_error { public: parse_exception(const std::string& err) : std::runtime_error{err} { } parse_exception(const std::string& err, std::size_t line_number) : std::runtime_error{err + " at line " + std::to_string(line_number)} { } }; inline bool is_number(char c) { return c >= '0' && c <= '9'; } /** * Helper object for consuming expected characters. */ template class consumer { public: consumer(std::string::iterator& it, const std::string::iterator& end, OnError&& on_error) : it_(it), end_(end), on_error_(std::forward(on_error)) { // nothing } void operator()(char c) { if (it_ == end_ || *it_ != c) on_error_(); ++it_; } template void operator()(const char (&str)[N]) { std::for_each(std::begin(str), std::end(str) - 1, [&](char c) { (*this)(c); }); } int eat_digits(int len) { int val = 0; for (int i = 0; i < len; ++i) { if (!is_number(*it_) || it_ == end_) on_error_(); val = 10 * val + (*it_++ - '0'); } return val; } void error() { on_error_(); } private: std::string::iterator& it_; const std::string::iterator& end_; OnError on_error_; }; template consumer make_consumer(std::string::iterator& it, const std::string::iterator& end, OnError&& on_error) { return consumer(it, end, std::forward(on_error)); } // replacement for std::getline to handle incorrectly line-ended files // https://stackoverflow.com/questions/6089231/getting-std-ifstream-to-handle-lf-cr-and-crlf namespace detail { inline std::istream& getline(std::istream& input, std::string& line) { line.clear(); std::istream::sentry sentry{input, true}; auto sb = input.rdbuf(); while (true) { auto c = sb->sbumpc(); if (c == '\r') { if (sb->sgetc() == '\n') c = sb->sbumpc(); } if (c == '\n') return input; if (c == std::istream::traits_type::eof()) { if (line.empty()) input.setstate(std::ios::eofbit); return input; } line.push_back(static_cast(c)); } } } /** * The parser class. */ class parser { public: /** * Parsers are constructed from streams. */ parser(std::istream& stream) : input_(stream) { // nothing } parser& operator=(const parser& parser) = delete; /** * Parses the stream this parser was created on until EOF. * @throw parse_exception if there are errors in parsing */ std::shared_ptr
parse() { std::shared_ptr
root = make_table(); table* curr_table = root.get(); while (detail::getline(input_, line_)) { line_number_++; auto it = line_.begin(); auto end = line_.end(); consume_whitespace(it, end); if (it == end || *it == '#') continue; if (*it == '[') { curr_table = root.get(); parse_table(it, end, curr_table); } else { parse_key_value(it, end, curr_table); consume_whitespace(it, end); eol_or_comment(it, end); } } return root; } private: #if defined _MSC_VER __declspec(noreturn) #elif defined __GNUC__ __attribute__((noreturn)) #endif void throw_parse_exception(const std::string& err) { throw parse_exception{err, line_number_}; } void parse_table(std::string::iterator& it, const std::string::iterator& end, table*& curr_table) { // remove the beginning keytable marker ++it; if (it == end) throw_parse_exception("Unexpected end of table"); if (*it == '[') parse_table_array(it, end, curr_table); else parse_single_table(it, end, curr_table); } void parse_single_table(std::string::iterator& it, const std::string::iterator& end, table*& curr_table) { if (it == end || *it == ']') throw_parse_exception("Table name cannot be empty"); std::string full_table_name; bool inserted = false; while (it != end && *it != ']') { auto part = parse_key(it, end, [](char c) { return c == '.' || c == ']'; }); if (part.empty()) throw_parse_exception("Empty component of table name"); if (!full_table_name.empty()) full_table_name += "."; full_table_name += part; if (curr_table->contains(part)) { auto b = curr_table->get(part); if (b->is_table()) curr_table = static_cast(b.get()); else if (b->is_table_array()) curr_table = std::static_pointer_cast(b) ->get() .back() .get(); else throw_parse_exception("Key " + full_table_name + "already exists as a value"); } else { inserted = true; curr_table->insert(part, make_table()); curr_table = static_cast(curr_table->get(part).get()); } consume_whitespace(it, end); if (it != end && *it == '.') ++it; consume_whitespace(it, end); } if (it == end) throw_parse_exception( "Unterminated table declaration; did you forget a ']'?"); // table already existed if (!inserted) { auto is_value = [](const std::pair&>& p) { return p.second->is_value(); }; // if there are any values, we can't add values to this table // since it has already been defined. If there aren't any // values, then it was implicitly created by something like // [a.b] if (curr_table->empty() || std::any_of(curr_table->begin(), curr_table->end(), is_value)) { throw_parse_exception("Redefinition of table " + full_table_name); } } ++it; consume_whitespace(it, end); eol_or_comment(it, end); } void parse_table_array(std::string::iterator& it, const std::string::iterator& end, table*& curr_table) { ++it; if (it == end || *it == ']') throw_parse_exception("Table array name cannot be empty"); std::string full_ta_name; while (it != end && *it != ']') { auto part = parse_key(it, end, [](char c) { return c == '.' || c == ']'; }); if (part.empty()) throw_parse_exception("Empty component of table array name"); if (!full_ta_name.empty()) full_ta_name += "."; full_ta_name += part; consume_whitespace(it, end); if (it != end && *it == '.') ++it; consume_whitespace(it, end); if (curr_table->contains(part)) { auto b = curr_table->get(part); // if this is the end of the table array name, add an // element to the table array that we just looked up if (it != end && *it == ']') { if (!b->is_table_array()) throw_parse_exception("Key " + full_ta_name + " is not a table array"); auto v = b->as_table_array(); v->get().push_back(make_table()); curr_table = v->get().back().get(); } // otherwise, just keep traversing down the key name else { if (b->is_table()) curr_table = static_cast(b.get()); else if (b->is_table_array()) curr_table = std::static_pointer_cast(b) ->get() .back() .get(); else throw_parse_exception("Key " + full_ta_name + " already exists as a value"); } } else { // if this is the end of the table array name, add a new // table array and a new table inside that array for us to // add keys to next if (it != end && *it == ']') { curr_table->insert(part, make_table_array()); auto arr = std::static_pointer_cast( curr_table->get(part)); arr->get().push_back(make_table()); curr_table = arr->get().back().get(); } // otherwise, create the implicitly defined table and move // down to it else { curr_table->insert(part, make_table()); curr_table = static_cast(curr_table->get(part).get()); } } } // consume the last "]]" if (it == end) throw_parse_exception("Unterminated table array name"); ++it; if (it == end) throw_parse_exception("Unterminated table array name"); ++it; consume_whitespace(it, end); eol_or_comment(it, end); } void parse_key_value(std::string::iterator& it, std::string::iterator& end, table* curr_table) { auto key = parse_key(it, end, [](char c) { return c == '='; }); if (curr_table->contains(key)) throw_parse_exception("Key " + key + " already present"); if (it == end || *it != '=') throw_parse_exception("Value must follow after a '='"); ++it; consume_whitespace(it, end); curr_table->insert(key, parse_value(it, end)); consume_whitespace(it, end); } template std::string parse_key(std::string::iterator& it, const std::string::iterator& end, Function&& fun) { consume_whitespace(it, end); if (*it == '"') { return parse_quoted_key(it, end); } else { auto bke = std::find_if(it, end, std::forward(fun)); return parse_bare_key(it, bke); } } std::string parse_bare_key(std::string::iterator& it, const std::string::iterator& end) { if (it == end) { throw_parse_exception("Bare key missing name"); } auto key_end = end; --key_end; consume_backwards_whitespace(key_end, it); ++key_end; std::string key{it, key_end}; if (std::find(it, key_end, '#') != key_end) { throw_parse_exception("Bare key " + key + " cannot contain #"); } if (std::find_if(it, key_end, [](char c) { return c == ' ' || c == '\t'; }) != key_end) { throw_parse_exception("Bare key " + key + " cannot contain whitespace"); } if (std::find_if(it, key_end, [](char c) { return c == '[' || c == ']'; }) != key_end) { throw_parse_exception("Bare key " + key + " cannot contain '[' or ']'"); } it = end; return key; } std::string parse_quoted_key(std::string::iterator& it, const std::string::iterator& end) { return string_literal(it, end, '"'); } enum class parse_type { STRING = 1, LOCAL_TIME, LOCAL_DATE, LOCAL_DATETIME, OFFSET_DATETIME, INT, FLOAT, BOOL, ARRAY, INLINE_TABLE }; std::shared_ptr parse_value(std::string::iterator& it, std::string::iterator& end) { parse_type type = determine_value_type(it, end); switch (type) { case parse_type::STRING: return parse_string(it, end); case parse_type::LOCAL_TIME: return parse_time(it, end); case parse_type::LOCAL_DATE: case parse_type::LOCAL_DATETIME: case parse_type::OFFSET_DATETIME: return parse_date(it, end); case parse_type::INT: case parse_type::FLOAT: return parse_number(it, end); case parse_type::BOOL: return parse_bool(it, end); case parse_type::ARRAY: return parse_array(it, end); case parse_type::INLINE_TABLE: return parse_inline_table(it, end); default: throw_parse_exception("Failed to parse value"); } } parse_type determine_value_type(const std::string::iterator& it, const std::string::iterator& end) { if (*it == '"' || *it == '\'') { return parse_type::STRING; } else if (is_time(it, end)) { return parse_type::LOCAL_TIME; } else if (auto dtype = date_type(it, end)) { return *dtype; } else if (is_number(*it) || *it == '-' || *it == '+') { return determine_number_type(it, end); } else if (*it == 't' || *it == 'f') { return parse_type::BOOL; } else if (*it == '[') { return parse_type::ARRAY; } else if (*it == '{') { return parse_type::INLINE_TABLE; } throw_parse_exception("Failed to parse value type"); } parse_type determine_number_type(const std::string::iterator& it, const std::string::iterator& end) { // determine if we are an integer or a float auto check_it = it; if (*check_it == '-' || *check_it == '+') ++check_it; while (check_it != end && is_number(*check_it)) ++check_it; if (check_it != end && *check_it == '.') { ++check_it; while (check_it != end && is_number(*check_it)) ++check_it; return parse_type::FLOAT; } else { return parse_type::INT; } } std::shared_ptr> parse_string(std::string::iterator& it, std::string::iterator& end) { auto delim = *it; assert(delim == '"' || delim == '\''); // end is non-const here because we have to be able to potentially // parse multiple lines in a string, not just one auto check_it = it; ++check_it; if (check_it != end && *check_it == delim) { ++check_it; if (check_it != end && *check_it == delim) { it = ++check_it; return parse_multiline_string(it, end, delim); } } return make_value(string_literal(it, end, delim)); } std::shared_ptr> parse_multiline_string(std::string::iterator& it, std::string::iterator& end, char delim) { std::stringstream ss; auto is_ws = [](char c) { return c == ' ' || c == '\t'; }; bool consuming = false; std::shared_ptr> ret; auto handle_line = [&](std::string::iterator& it, std::string::iterator& end) { if (consuming) { it = std::find_if_not(it, end, is_ws); // whole line is whitespace if (it == end) return; } consuming = false; while (it != end) { // handle escaped characters if (delim == '"' && *it == '\\') { auto check = it; // check if this is an actual escape sequence or a // whitespace escaping backslash ++check; consume_whitespace(check, end); if (check == end) { consuming = true; break; } ss << parse_escape_code(it, end); continue; } // if we can end the string if (std::distance(it, end) >= 3) { auto check = it; // check for """ if (*check++ == delim && *check++ == delim && *check++ == delim) { it = check; ret = make_value(ss.str()); break; } } ss << *it++; } }; // handle the remainder of the current line handle_line(it, end); if (ret) return ret; // start eating lines while (detail::getline(input_, line_)) { ++line_number_; it = line_.begin(); end = line_.end(); handle_line(it, end); if (ret) return ret; if (!consuming) ss << std::endl; } throw_parse_exception("Unterminated multi-line basic string"); } std::string string_literal(std::string::iterator& it, const std::string::iterator& end, char delim) { ++it; std::string val; while (it != end) { // handle escaped characters if (delim == '"' && *it == '\\') { val += parse_escape_code(it, end); } else if (*it == delim) { ++it; consume_whitespace(it, end); return val; } else { val += *it++; } } throw_parse_exception("Unterminated string literal"); } std::string parse_escape_code(std::string::iterator& it, const std::string::iterator& end) { ++it; if (it == end) throw_parse_exception("Invalid escape sequence"); char value; if (*it == 'b') { value = '\b'; } else if (*it == 't') { value = '\t'; } else if (*it == 'n') { value = '\n'; } else if (*it == 'f') { value = '\f'; } else if (*it == 'r') { value = '\r'; } else if (*it == '"') { value = '"'; } else if (*it == '\\') { value = '\\'; } else if (*it == 'u' || *it == 'U') { return parse_unicode(it, end); } else { throw_parse_exception("Invalid escape sequence"); } ++it; return std::string(1, value); } std::string parse_unicode(std::string::iterator& it, const std::string::iterator& end) { bool large = *it++ == 'U'; auto codepoint = parse_hex(it, end, large ? 0x10000000 : 0x1000); if ((codepoint > 0xd7ff && codepoint < 0xe000) || codepoint > 0x10ffff) { throw_parse_exception( "Unicode escape sequence is not a Unicode scalar value"); } std::string result; // See Table 3-6 of the Unicode standard if (codepoint <= 0x7f) { // 1-byte codepoints: 00000000 0xxxxxxx // repr: 0xxxxxxx result += static_cast(codepoint & 0x7f); } else if (codepoint <= 0x7ff) { // 2-byte codepoints: 00000yyy yyxxxxxx // repr: 110yyyyy 10xxxxxx // // 0x1f = 00011111 // 0xc0 = 11000000 // result += static_cast(0xc0 | ((codepoint >> 6) & 0x1f)); // // 0x80 = 10000000 // 0x3f = 00111111 // result += static_cast(0x80 | (codepoint & 0x3f)); } else if (codepoint <= 0xffff) { // 3-byte codepoints: zzzzyyyy yyxxxxxx // repr: 1110zzzz 10yyyyyy 10xxxxxx // // 0xe0 = 11100000 // 0x0f = 00001111 // result += static_cast(0xe0 | ((codepoint >> 12) & 0x0f)); result += static_cast(0x80 | ((codepoint >> 6) & 0x1f)); result += static_cast(0x80 | (codepoint & 0x3f)); } else { // 4-byte codepoints: 000uuuuu zzzzyyyy yyxxxxxx // repr: 11110uuu 10uuzzzz 10yyyyyy 10xxxxxx // // 0xf0 = 11110000 // 0x07 = 00000111 // result += static_cast(0xf0 | ((codepoint >> 18) & 0x07)); result += static_cast(0x80 | ((codepoint >> 12) & 0x3f)); result += static_cast(0x80 | ((codepoint >> 6) & 0x3f)); result += static_cast(0x80 | (codepoint & 0x3f)); } return result; } uint32_t parse_hex(std::string::iterator& it, const std::string::iterator& end, uint32_t place) { uint32_t value = 0; while (place > 0) { if (it == end) throw_parse_exception("Unexpected end of unicode sequence"); if (!is_hex(*it)) throw_parse_exception("Invalid unicode escape sequence"); value += place * hex_to_digit(*it++); place /= 16; } return value; } bool is_hex(char c) { return is_number(c) || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F'); } uint32_t hex_to_digit(char c) { if (is_number(c)) return static_cast(c - '0'); return 10 + static_cast( c - ((c >= 'a' && c <= 'f') ? 'a' : 'A')); } std::shared_ptr parse_number(std::string::iterator& it, const std::string::iterator& end) { auto check_it = it; auto check_end = find_end_of_number(it, end); auto eat_sign = [&]() { if (check_it != end && (*check_it == '-' || *check_it == '+')) ++check_it; }; eat_sign(); auto eat_numbers = [&]() { auto beg = check_it; while (check_it != end && is_number(*check_it)) { ++check_it; if (check_it != end && *check_it == '_') { ++check_it; if (check_it == end || !is_number(*check_it)) throw_parse_exception("Malformed number"); } } if (check_it == beg) throw_parse_exception("Malformed number"); }; auto check_no_leading_zero = [&]() { if (check_it != end && *check_it == '0' && check_it + 1 != check_end && check_it[1] != '.') { throw_parse_exception("Numbers may not have leading zeros"); } }; check_no_leading_zero(); eat_numbers(); if (check_it != end && (*check_it == '.' || *check_it == 'e' || *check_it == 'E')) { bool is_exp = *check_it == 'e' || *check_it == 'E'; ++check_it; if (check_it == end) throw_parse_exception("Floats must have trailing digits"); auto eat_exp = [&]() { eat_sign(); check_no_leading_zero(); eat_numbers(); }; if (is_exp) eat_exp(); else eat_numbers(); if (!is_exp && check_it != end && (*check_it == 'e' || *check_it == 'E')) { ++check_it; eat_exp(); } return parse_float(it, check_it); } else { return parse_int(it, check_it); } } std::shared_ptr> parse_int(std::string::iterator& it, const std::string::iterator& end) { std::string v{it, end}; v.erase(std::remove(v.begin(), v.end(), '_'), v.end()); it = end; try { return make_value(std::stoll(v)); } catch (const std::invalid_argument& ex) { throw_parse_exception("Malformed number (invalid argument: " + std::string{ex.what()} + ")"); } catch (const std::out_of_range& ex) { throw_parse_exception("Malformed number (out of range: " + std::string{ex.what()} + ")"); } } std::shared_ptr> parse_float(std::string::iterator& it, const std::string::iterator& end) { std::string v{it, end}; v.erase(std::remove(v.begin(), v.end(), '_'), v.end()); it = end; try { return make_value(std::stod(v)); } catch (const std::invalid_argument& ex) { throw_parse_exception("Malformed number (invalid argument: " + std::string{ex.what()} + ")"); } catch (const std::out_of_range& ex) { throw_parse_exception("Malformed number (out of range: " + std::string{ex.what()} + ")"); } } std::shared_ptr> parse_bool(std::string::iterator& it, const std::string::iterator& end) { auto eat = make_consumer(it, end, [this]() { throw_parse_exception("Attempted to parse invalid boolean value"); }); if (*it == 't') { eat("true"); return make_value(true); } else if (*it == 'f') { eat("false"); return make_value(false); } eat.error(); return nullptr; } std::string::iterator find_end_of_number(std::string::iterator it, std::string::iterator end) { return std::find_if(it, end, [](char c) { return !is_number(c) && c != '_' && c != '.' && c != 'e' && c != 'E' && c != '-' && c != '+'; }); } std::string::iterator find_end_of_date(std::string::iterator it, std::string::iterator end) { return std::find_if(it, end, [](char c) { return !is_number(c) && c != 'T' && c != 'Z' && c != ':' && c != '-' && c != '+' && c != '.'; }); } std::string::iterator find_end_of_time(std::string::iterator it, std::string::iterator end) { return std::find_if(it, end, [](char c) { return !is_number(c) && c != ':' && c != '.'; }); } local_time read_time(std::string::iterator& it, const std::string::iterator& end) { auto time_end = find_end_of_time(it, end); auto eat = make_consumer( it, time_end, [&]() { throw_parse_exception("Malformed time"); }); local_time ltime; ltime.hour = eat.eat_digits(2); eat(':'); ltime.minute = eat.eat_digits(2); eat(':'); ltime.second = eat.eat_digits(2); int power = 100000; if (it != time_end && *it == '.') { ++it; while (it != time_end && is_number(*it)) { ltime.microsecond += power * (*it++ - '0'); power /= 10; } } if (it != time_end) throw_parse_exception("Malformed time"); return ltime; } std::shared_ptr> parse_time(std::string::iterator& it, const std::string::iterator& end) { return make_value(read_time(it, end)); } std::shared_ptr parse_date(std::string::iterator& it, const std::string::iterator& end) { auto date_end = find_end_of_date(it, end); auto eat = make_consumer( it, date_end, [&]() { throw_parse_exception("Malformed date"); }); local_date ldate; ldate.year = eat.eat_digits(4); eat('-'); ldate.month = eat.eat_digits(2); eat('-'); ldate.day = eat.eat_digits(2); if (it == date_end) return make_value(ldate); eat('T'); local_datetime ldt; static_cast(ldt) = ldate; static_cast(ldt) = read_time(it, date_end); if (it == date_end) return make_value(ldt); offset_datetime dt; static_cast(dt) = ldt; int hoff = 0; int moff = 0; if (*it == '+' || *it == '-') { auto plus = *it == '+'; ++it; hoff = eat.eat_digits(2); dt.hour_offset = (plus) ? hoff : -hoff; eat(':'); moff = eat.eat_digits(2); dt.minute_offset = (plus) ? moff : -moff; } else if (*it == 'Z') { ++it; } if (it != date_end) throw_parse_exception("Malformed date"); return make_value(dt); } std::shared_ptr parse_array(std::string::iterator& it, std::string::iterator& end) { // this gets ugly because of the "homogeneity" restriction: // arrays can either be of only one type, or contain arrays // (each of those arrays could be of different types, though) // // because of the latter portion, we don't really have a choice // but to represent them as arrays of base values... ++it; // ugh---have to read the first value to determine array type... skip_whitespace_and_comments(it, end); // edge case---empty array if (*it == ']') { ++it; return make_array(); } auto val_end = std::find_if( it, end, [](char c) { return c == ',' || c == ']' || c == '#'; }); parse_type type = determine_value_type(it, val_end); switch (type) { case parse_type::STRING: return parse_value_array(it, end); case parse_type::LOCAL_TIME: return parse_value_array(it, end); case parse_type::LOCAL_DATE: return parse_value_array(it, end); case parse_type::LOCAL_DATETIME: return parse_value_array(it, end); case parse_type::OFFSET_DATETIME: return parse_value_array(it, end); case parse_type::INT: return parse_value_array(it, end); case parse_type::FLOAT: return parse_value_array(it, end); case parse_type::BOOL: return parse_value_array(it, end); case parse_type::ARRAY: return parse_object_array(&parser::parse_array, '[', it, end); case parse_type::INLINE_TABLE: return parse_object_array( &parser::parse_inline_table, '{', it, end); default: throw_parse_exception("Unable to parse array"); } } template std::shared_ptr parse_value_array(std::string::iterator& it, std::string::iterator& end) { auto arr = make_array(); while (it != end && *it != ']') { auto value = parse_value(it, end); if (auto v = value->as()) arr->get().push_back(value); else throw_parse_exception("Arrays must be heterogeneous"); skip_whitespace_and_comments(it, end); if (*it != ',') break; ++it; skip_whitespace_and_comments(it, end); } if (it != end) ++it; return arr; } template std::shared_ptr parse_object_array(Function&& fun, char delim, std::string::iterator& it, std::string::iterator& end) { auto arr = make_element(); while (it != end && *it != ']') { if (*it != delim) throw_parse_exception("Unexpected character in array"); arr->get().push_back(((*this).*fun)(it, end)); skip_whitespace_and_comments(it, end); if (*it != ',') break; ++it; skip_whitespace_and_comments(it, end); } if (it == end || *it != ']') throw_parse_exception("Unterminated array"); ++it; return arr; } std::shared_ptr
parse_inline_table(std::string::iterator& it, std::string::iterator& end) { auto tbl = make_table(); do { ++it; if (it == end) throw_parse_exception("Unterminated inline table"); consume_whitespace(it, end); parse_key_value(it, end, tbl.get()); consume_whitespace(it, end); } while (*it == ','); if (it == end || *it != '}') throw_parse_exception("Unterminated inline table"); ++it; consume_whitespace(it, end); return tbl; } void skip_whitespace_and_comments(std::string::iterator& start, std::string::iterator& end) { consume_whitespace(start, end); while (start == end || *start == '#') { if (!detail::getline(input_, line_)) throw_parse_exception("Unclosed array"); line_number_++; start = line_.begin(); end = line_.end(); consume_whitespace(start, end); } } void consume_whitespace(std::string::iterator& it, const std::string::iterator& end) { while (it != end && (*it == ' ' || *it == '\t')) ++it; } void consume_backwards_whitespace(std::string::iterator& back, const std::string::iterator& front) { while (back != front && (*back == ' ' || *back == '\t')) --back; } void eol_or_comment(const std::string::iterator& it, const std::string::iterator& end) { if (it != end && *it != '#') throw_parse_exception("Unidentified trailing character '" + std::string{*it} + "'---did you forget a '#'?"); } bool is_time(const std::string::iterator& it, const std::string::iterator& end) { auto time_end = find_end_of_time(it, end); auto len = std::distance(it, time_end); if (len < 8) return false; if (it[2] != ':' || it[5] != ':') return false; if (len > 8) return it[8] == '.' && len > 9; return true; } option date_type(const std::string::iterator& it, const std::string::iterator& end) { auto date_end = find_end_of_date(it, end); auto len = std::distance(it, date_end); if (len < 10) return {}; if (it[4] != '-' || it[7] != '-') return {}; if (len >= 19 && it[10] == 'T' && is_time(it + 11, date_end)) { // datetime type auto time_end = find_end_of_time(it + 11, date_end); if (time_end == date_end) return {parse_type::LOCAL_DATETIME}; else return {parse_type::OFFSET_DATETIME}; } else if (len == 10) { // just a regular date return {parse_type::LOCAL_DATE}; } return {}; } std::istream& input_; std::string line_; std::size_t line_number_ = 0; }; /** * Utility function to parse a file as a TOML file. Returns the root table. * Throws a parse_exception if the file cannot be opened. */ inline std::shared_ptr
parse_file(const std::string& filename) { #if defined(BOOST_NOWIDE_FSTREAM_INCLUDED_HPP) boost::nowide::ifstream file{filename.c_str()}; #elif defined(NOWIDE_FSTREAM_INCLUDED_HPP) nowide::ifstream file{filename.c_str()}; #else std::ifstream file{filename}; #endif if (!file.is_open()) throw parse_exception{filename + " could not be opened for parsing"}; parser p{file}; return p.parse(); } template struct value_accept; template <> struct value_accept<> { template static void accept(const base&, Visitor&&, Args&&...) { // nothing } }; template struct value_accept { template static void accept(const base& b, Visitor&& visitor, Args&&... args) { if (auto v = b.as()) { visitor.visit(*v, std::forward(args)...); } else { value_accept::accept(b, std::forward(visitor), std::forward(args)...); } } }; /** * base implementation of accept() that calls visitor.visit() on the concrete * class. */ template void base::accept(Visitor&& visitor, Args&&... args) const { if (is_value()) { using value_acceptor = value_accept; value_acceptor::accept(*this, std::forward(visitor), std::forward(args)...); } else if (is_table()) { visitor.visit(static_cast(*this), std::forward(args)...); } else if (is_array()) { visitor.visit(static_cast(*this), std::forward(args)...); } else if (is_table_array()) { visitor.visit(static_cast(*this), std::forward(args)...); } } /** * Writer that can be passed to accept() functions of cpptoml objects and * will output valid TOML to a stream. */ class toml_writer { public: /** * Construct a toml_writer that will write to the given stream */ toml_writer(std::ostream& s, const std::string& indent_space = "\t") : stream_(s), indent_(indent_space), has_naked_endline_(false) { // nothing } public: /** * Output a base value of the TOML tree. */ template void visit(const value& v, bool = false) { write(v); } /** * Output a table element of the TOML tree */ void visit(const table& t, bool in_array = false) { write_table_header(in_array); std::vector values; std::vector tables; for (const auto& i : t) { if (i.second->is_table() || i.second->is_table_array()) { tables.push_back(i.first); } else { values.push_back(i.first); } } for (unsigned int i = 0; i < values.size(); ++i) { path_.push_back(values[i]); if (i > 0) endline(); write_table_item_header(*t.get(values[i])); t.get(values[i])->accept(*this, false); path_.pop_back(); } for (unsigned int i = 0; i < tables.size(); ++i) { path_.push_back(tables[i]); if (values.size() > 0 || i > 0) endline(); write_table_item_header(*t.get(tables[i])); t.get(tables[i])->accept(*this, false); path_.pop_back(); } endline(); } /** * Output an array element of the TOML tree */ void visit(const array& a, bool = false) { write("["); for (unsigned int i = 0; i < a.get().size(); ++i) { if (i > 0) write(", "); if (a.get()[i]->is_array()) { a.get()[i]->as_array()->accept(*this, true); } else { a.get()[i]->accept(*this, true); } } write("]"); } /** * Output a table_array element of the TOML tree */ void visit(const table_array& t, bool = false) { for (unsigned int j = 0; j < t.get().size(); ++j) { if (j > 0) endline(); t.get()[j]->accept(*this, true); } endline(); } /** * Escape a string for output. */ static std::string escape_string(const std::string& str) { std::string res; for (auto it = str.begin(); it != str.end(); ++it) { if (*it == '\b') { res += "\\b"; } else if (*it == '\t') { res += "\\t"; } else if (*it == '\n') { res += "\\n"; } else if (*it == '\f') { res += "\\f"; } else if (*it == '\r') { res += "\\r"; } else if (*it == '"') { res += "\\\""; } else if (*it == '\\') { res += "\\\\"; } else if (*it >= 0x0000 && *it <= 0x001f) { res += "\\u"; std::stringstream ss; ss << std::hex << static_cast(*it); res += ss.str(); } else { res += *it; } } return res; } protected: /** * Write out a string. */ void write(const value& v) { write("\""); write(escape_string(v.get())); write("\""); } /** * Write out a double. */ void write(const value& v) { std::ios::fmtflags flags{stream_.flags()}; stream_ << std::showpoint; write(v.get()); stream_.flags(flags); } /** * Write out an integer, local_date, local_time, local_datetime, or * offset_datetime. */ template typename std::enable_if::value>::type write(const value& v) { write(v.get()); } /** * Write out a boolean. */ void write(const value& v) { write((v.get() ? "true" : "false")); } /** * Write out the header of a table. */ void write_table_header(bool in_array = false) { if (!path_.empty()) { indent(); write("["); if (in_array) { write("["); } for (unsigned int i = 0; i < path_.size(); ++i) { if (i > 0) { write("."); } if (path_[i].find_first_not_of("ABCDEFGHIJKLMNOPQRSTUVWXYZabcde" "fghijklmnopqrstuvwxyz0123456789" "_-") == std::string::npos) { write(path_[i]); } else { write("\""); write(escape_string(path_[i])); write("\""); } } if (in_array) { write("]"); } write("]"); endline(); } } /** * Write out the identifier for an item in a table. */ void write_table_item_header(const base& b) { if (!b.is_table() && !b.is_table_array()) { indent(); if (path_.back().find_first_not_of("ABCDEFGHIJKLMNOPQRSTUVWXYZabcde" "fghijklmnopqrstuvwxyz0123456789" "_-") == std::string::npos) { write(path_.back()); } else { write("\""); write(escape_string(path_.back())); write("\""); } write(" = "); } } private: /** * Indent the proper number of tabs given the size of * the path. */ void indent() { for (std::size_t i = 1; i < path_.size(); ++i) write(indent_); } /** * Write a value out to the stream. */ template void write(const T& v) { stream_ << v; has_naked_endline_ = false; } /** * Write an endline out to the stream */ void endline() { if (!has_naked_endline_) { stream_ << "\n"; has_naked_endline_ = true; } } private: std::ostream& stream_; const std::string indent_; std::vector path_; bool has_naked_endline_; }; inline std::ostream& operator<<(std::ostream& stream, const base& b) { toml_writer writer{stream}; b.accept(writer); return stream; } template std::ostream& operator<<(std::ostream& stream, const value& v) { toml_writer writer{stream}; v.accept(writer); return stream; } inline std::ostream& operator<<(std::ostream& stream, const table& t) { toml_writer writer{stream}; t.accept(writer); return stream; } inline std::ostream& operator<<(std::ostream& stream, const table_array& t) { toml_writer writer{stream}; t.accept(writer); return stream; } inline std::ostream& operator<<(std::ostream& stream, const array& a) { toml_writer writer{stream}; a.accept(writer); return stream; } } #endif