From 42253150e43fa4289130d4b53729e618908a251e Mon Sep 17 00:00:00 2001 From: kumquat-ir <66188216+kumquat-ir@users.noreply.github.com> Date: Thu, 15 Apr 2021 23:19:01 -0700 Subject: add toml11 as dependency --- CMakeLists.txt | 1 + COPYING.md | 24 + libraries/README.md | 7 + libraries/toml11/CMakeLists.txt | 5 + libraries/toml11/LICENSE | 21 + libraries/toml11/README.md | 1918 ++++++++++++++++++ libraries/toml11/include/toml.hpp | 46 + libraries/toml11/include/toml/color.hpp | 64 + libraries/toml11/include/toml/combinator.hpp | 306 +++ libraries/toml11/include/toml/comments.hpp | 466 +++++ libraries/toml11/include/toml/datetime.hpp | 631 ++++++ libraries/toml11/include/toml/exception.hpp | 65 + libraries/toml11/include/toml/from.hpp | 20 + libraries/toml11/include/toml/get.hpp | 1068 ++++++++++ libraries/toml11/include/toml/into.hpp | 20 + libraries/toml11/include/toml/lexer.hpp | 270 +++ libraries/toml11/include/toml/literal.hpp | 112 ++ libraries/toml11/include/toml/macros.hpp | 121 ++ libraries/toml11/include/toml/parser.hpp | 2177 +++++++++++++++++++++ libraries/toml11/include/toml/region.hpp | 417 ++++ libraries/toml11/include/toml/result.hpp | 717 +++++++ libraries/toml11/include/toml/serializer.hpp | 853 ++++++++ libraries/toml11/include/toml/source_location.hpp | 233 +++ libraries/toml11/include/toml/storage.hpp | 43 + libraries/toml11/include/toml/string.hpp | 224 +++ libraries/toml11/include/toml/traits.hpp | 300 +++ libraries/toml11/include/toml/types.hpp | 150 ++ libraries/toml11/include/toml/utility.hpp | 93 + libraries/toml11/include/toml/value.hpp | 2023 +++++++++++++++++++ 29 files changed, 12395 insertions(+) create mode 100644 libraries/toml11/CMakeLists.txt create mode 100644 libraries/toml11/LICENSE create mode 100644 libraries/toml11/README.md create mode 100644 libraries/toml11/include/toml.hpp create mode 100644 libraries/toml11/include/toml/color.hpp create mode 100644 libraries/toml11/include/toml/combinator.hpp create mode 100644 libraries/toml11/include/toml/comments.hpp create mode 100644 libraries/toml11/include/toml/datetime.hpp create mode 100644 libraries/toml11/include/toml/exception.hpp create mode 100644 libraries/toml11/include/toml/from.hpp create mode 100644 libraries/toml11/include/toml/get.hpp create mode 100644 libraries/toml11/include/toml/into.hpp create mode 100644 libraries/toml11/include/toml/lexer.hpp create mode 100644 libraries/toml11/include/toml/literal.hpp create mode 100644 libraries/toml11/include/toml/macros.hpp create mode 100644 libraries/toml11/include/toml/parser.hpp create mode 100644 libraries/toml11/include/toml/region.hpp create mode 100644 libraries/toml11/include/toml/result.hpp create mode 100644 libraries/toml11/include/toml/serializer.hpp create mode 100644 libraries/toml11/include/toml/source_location.hpp create mode 100644 libraries/toml11/include/toml/storage.hpp create mode 100644 libraries/toml11/include/toml/string.hpp create mode 100644 libraries/toml11/include/toml/traits.hpp create mode 100644 libraries/toml11/include/toml/types.hpp create mode 100644 libraries/toml11/include/toml/utility.hpp create mode 100644 libraries/toml11/include/toml/value.hpp diff --git a/CMakeLists.txt b/CMakeLists.txt index 1c93e7a9..cfba3430 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -265,6 +265,7 @@ add_subdirectory(libraries/iconfix) # fork of Qt's QIcon loader add_subdirectory(libraries/LocalPeer) # fork of a library from Qt solutions add_subdirectory(libraries/classparser) # google analytics library add_subdirectory(libraries/optional-bare) +add_subdirectory(libraries/toml11) # toml parser ############################### Built Artifacts ############################### diff --git a/COPYING.md b/COPYING.md index c0c98606..ea8fe479 100644 --- a/COPYING.md +++ b/COPYING.md @@ -251,3 +251,27 @@ FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + +# toml11 + + The MIT License (MIT) + + Copyright (c) 2017 Toru Niina + + Permission is hereby granted, free of charge, to any person obtaining a copy + of this software and associated documentation files (the "Software"), to deal + in the Software without restriction, including without limitation the rights + to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + copies of the Software, and to permit persons to whom the Software is + furnished to do so, subject to the following conditions: + + The above copyright notice and this permission notice shall be included in + all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + THE SOFTWARE. diff --git a/libraries/README.md b/libraries/README.md index cdc72004..76ee8c46 100644 --- a/libraries/README.md +++ b/libraries/README.md @@ -158,3 +158,10 @@ A Google Analytics library for Qt. BSD licensed, derived from [qt-google-analytics](https://github.com/HSAnet/qt-google-analytics). Modifications include better handling of IP anonymization (can be enabled) and general improvements of the API (application handles persistence and ID generation instead of the library). + +## toml11 +A C++11 TOML language parser. Used by Forge 1.14+ to store mod metadata. + +See [github repo](https://github.com/ToruNiina/toml11). + +Licenced under the MIT licence. diff --git a/libraries/toml11/CMakeLists.txt b/libraries/toml11/CMakeLists.txt new file mode 100644 index 00000000..556ec150 --- /dev/null +++ b/libraries/toml11/CMakeLists.txt @@ -0,0 +1,5 @@ +cmake_minimum_required(VERSION 3.1) +project(toml11) + +add_library(toml11 INTERFACE) +target_include_directories(toml11 INTERFACE "${CMAKE_CURRENT_SOURCE_DIR}/include") diff --git a/libraries/toml11/LICENSE b/libraries/toml11/LICENSE new file mode 100644 index 00000000..f55c511d --- /dev/null +++ b/libraries/toml11/LICENSE @@ -0,0 +1,21 @@ +The MIT License (MIT) + +Copyright (c) 2017 Toru Niina + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in +all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +THE SOFTWARE. diff --git a/libraries/toml11/README.md b/libraries/toml11/README.md new file mode 100644 index 00000000..d5bc1c81 --- /dev/null +++ b/libraries/toml11/README.md @@ -0,0 +1,1918 @@ +toml11 +====== + +[![Build Status on GitHub Actions](https://github.com/ToruNiina/toml11/workflows/build/badge.svg)](https://github.com/ToruNiina/toml11/actions) +[![Build Status on TravisCI](https://travis-ci.org/ToruNiina/toml11.svg?branch=master)](https://travis-ci.org/ToruNiina/toml11) +[![Build status on Appveyor](https://ci.appveyor.com/api/projects/status/m2n08a926asvg5mg/branch/master?svg=true)](https://ci.appveyor.com/project/ToruNiina/toml11/branch/master) +[![Build status on CircleCI](https://circleci.com/gh/ToruNiina/toml11/tree/master.svg?style=svg)](https://circleci.com/gh/ToruNiina/toml11/tree/master) +[![Version](https://img.shields.io/github/release/ToruNiina/toml11.svg?style=flat)](https://github.com/ToruNiina/toml11/releases) +[![License](https://img.shields.io/github/license/ToruNiina/toml11.svg?style=flat)](LICENSE) +[![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.1209136.svg)](https://doi.org/10.5281/zenodo.1209136) + +toml11 is a C++11 (or later) header-only toml parser/encoder depending only on C++ standard library. + +- It is compatible to the latest version of [TOML v1.0.0](https://toml.io/en/v1.0.0). +- It is one of the most TOML standard compliant libraries, tested with [the language agnostic test suite for TOML parsers by BurntSushi](https://github.com/BurntSushi/toml-test). +- It shows highly informative error messages. You can see the error messages about invalid files at [CircleCI](https://circleci.com/gh/ToruNiina/toml11). +- It has configurable container. You can use any random-access containers and key-value maps as backend containers. +- It optionally preserves comments without any overhead. +- It has configurable serializer that supports comments, inline tables, literal strings and multiline strings. +- It supports user-defined type conversion from/into toml values. +- It correctly handles UTF-8 sequences, with or without BOM, both on posix and Windows. + +## Example + +```cpp +#include +#include + +int main() +{ + // ```toml + // title = "an example toml file" + // nums = [3, 1, 4, 1, 5] + // ``` + auto data = toml::parse("example.toml"); + + // find a value with the specified type from a table + std::string title = toml::find(data, "title"); + + // convert the whole array into any container automatically + std::vector nums = toml::find>(data, "nums"); + + // access with STL-like manner + if(not data.contains("foo")) + { + data["foo"] = "bar"; + } + + // pass a fallback + std::string name = toml::find_or(data, "name", "not found"); + + // width-dependent formatting + std::cout << std::setw(80) << data << std::endl; + + return 0; +} +``` + +## Table of Contents + +- [Integration](#integration) +- [Decoding a toml file](#decoding-a-toml-file) + - [In the case of syntax error](#in-the-case-of-syntax-error) + - [Invalid UTF-8 Codepoints](#invalid-utf-8-codepoints) +- [Finding a toml value](#finding-a-toml-value) + - [Finding a value in a table](#finding-a-value-in-a-table) + - [In case of error](#in-case-of-error) + - [Dotted keys](#dotted-keys) +- [Casting a toml value](#casting-a-toml-value) +- [Checking value type](#checking-value-type) +- [More about conversion](#more-about-conversion) + - [Converting an array](#converting-an-array) + - [Converting a table](#converting-a-table) + - [Getting an array of tables](#getting-an-array-of-tables) + - [Cost of conversion](#cost-of-conversion) + - [Converting datetime and its variants](#converting-datetime-and-its-variants) +- [Getting with a fallback](#getting-with-a-fallback) +- [Expecting conversion](#expecting-conversion) +- [Visiting a toml::value](#visiting-a-tomlvalue) +- [Constructing a toml::value](#constructing-a-tomlvalue) +- [Preserving Comments](#preserving-comments) +- [Customizing containers](#customizing-containers) +- [TOML literal](#toml-literal) +- [Conversion between toml value and arbitrary types](#conversion-between-toml-value-and-arbitrary-types) +- [Formatting user-defined error messages](#formatting-user-defined-error-messages) +- [Obtaining location information](#obtaining-location-information) +- [Exceptions](#exceptions) +- [Colorize Error Messages](#colorize-error-messages) +- [Serializing TOML data](#serializing-toml-data) +- [Underlying types](#underlying-types) +- [Unreleased TOML features](#unreleased-toml-features) +- [Breaking Changes from v2](#breaking-changes-from-v2) +- [Running Tests](#running-tests) +- [Contributors](#contributors) +- [Licensing Terms](#licensing-terms) + +## Integration + +Just include the file after adding it to the include path. + +```cpp +#include // that's all! now you can use it. +#include + +int main() +{ + const auto data = toml::parse("example.toml"); + const auto title = toml::find(data, "title"); + std::cout << "the title is " << title << std::endl; + return 0; +} +``` + +The convenient way is to add this repository as a git-submodule or to install +it in your system by CMake. + +Note for MSVC: We recommend to set `/Zc:__cplusplus` to detect C++ version correctly. + +## Decoding a toml file + +To parse a toml file, the only thing you have to do is +to pass a filename to the `toml::parse` function. + +```cpp +const std::string fname("sample.toml"); +const toml::value data = toml::parse(fname); +``` + +As required by the TOML specification, the top-level value is always a table. +You can find a value inside it, cast it into a table explicitly, and insert it as a value into other `toml::value`. + +If it encounters an error while opening a file, it will throw `std::runtime_error`. + +You can also pass a `std::istream` to the `toml::parse` function. +To show a filename in an error message, however, it is recommended to pass the +filename with the stream. + +```cpp +std::ifstream ifs("sample.toml", std::ios_base::binary); +assert(ifs.good()); +const auto data = toml::parse(ifs, /*optional -> */ "sample.toml"); +``` + +**Note**: When you are **on Windows, open a file in binary mode**. +If a file is opened in text-mode, CRLF ("\r\n") will automatically be +converted to LF ("\n") and this causes inconsistency between file size +and the contents that would be read. This causes weird error. + +### In the case of syntax error + +If there is a syntax error in a toml file, `toml::parse` will throw +`toml::syntax_error` that inherits `std::exception`. + +toml11 has clean and informative error messages inspired by Rust and +it looks like the following. + +```console +terminate called after throwing an instance of 'toml::syntax_error' + what(): [error] toml::parse_table: invalid line format # error description + --> example.toml # file name + 3 | a = 42 = true # line num and content + | ^------ expected newline, but got '='. # error reason +``` + +If you (mistakenly) duplicate tables and got an error, it is helpful to see +where they are. toml11 shows both at the same time like the following. + +```console +terminate called after throwing an instance of 'toml::syntax_error' + what(): [error] toml::insert_value: table ("table") already exists. + --> duplicate-table.toml + 1 | [table] + | ~~~~~~~ table already exists here + ... + 3 | [table] + | ~~~~~~~ table defined twice +``` + +When toml11 encounters a malformed value, it tries to detect what type it is. +Then it shows hints to fix the format. An error message while reading one of +the malformed files in [the language agnostic test suite](https://github.com/BurntSushi/toml-test). +is shown below. + +```console +what(): [error] bad time: should be HH:MM:SS.subsec + --> ./datetime-malformed-no-secs.toml + 1 | no-secs = 1987-07-05T17:45Z + | ^------- HH:MM:SS.subsec + | +Hint: pass: 1979-05-27T07:32:00, 1979-05-27 07:32:00.999999 +Hint: fail: 1979-05-27T7:32:00, 1979-05-27 17:32 +``` + +You can find other examples in a job named `output_result` on +[CircleCI](https://circleci.com/gh/ToruNiina/toml11). + +Since the error message generation is generally a difficult task, the current +status is not ideal. If you encounter a weird error message, please let us know +and contribute to improve the quality! + +### Invalid UTF-8 codepoints + +It throws `syntax_error` if a value of an escape sequence +representing unicode character is not a valid UTF-8 codepoint. + +```console + what(): [error] toml::read_utf8_codepoint: input codepoint is too large. + --> utf8.toml + 1 | exceeds_unicode = "\U0011FFFF example" + | ^--------- should be in [0x00..0x10FFFF] +``` + +## Finding a toml value + +After parsing successfully, you can obtain the values from the result of +`toml::parse` using `toml::find` function. + +```toml +# sample.toml +answer = 42 +pi = 3.14 +numbers = [1,2,3] +time = 1979-05-27T07:32:00Z +``` + +``` cpp +const auto data = toml::parse("sample.toml"); +const auto answer = toml::find(data, "answer"); +const auto pi = toml::find(data, "pi"); +const auto numbers = toml::find>(data, "numbers"); +const auto timepoint = toml::find(data, "time"); +``` + +By default, `toml::find` returns a `toml::value`. + +```cpp +const toml::value& answer = toml::find(data, "answer"); +``` + +When you pass an exact TOML type that does not require type conversion, +`toml::find` returns a reference without copying the value. + +```cpp +const auto data = toml::parse("sample.toml"); +const auto& answer = toml::find(data, "answer"); +``` + +If the specified type requires conversion, you can't take a reference to the value. +See also [underlying types](#underlying-types). + +**NOTE**: For some technical reason, automatic conversion between `integer` and +`floating` is not supported. If you want to get a floating value even if a value +has integer value, you need to convert it manually after obtaining a value, +like the followings. + +```cpp +const auto vx = toml::find(data, "x"); +double x = vx.is_floating() ? vx.as_floating(std::nothrow) : + static_cast(vx.as_integer()); // it throws if vx is neither + // floating nor integer. +``` + +### Finding a value in a table + +There are several way to get a value defined in a table. +First, you can get a table as a normal value and find a value from the table. + +```toml +[fruit] +name = "apple" +[fruit.physical] +color = "red" +shape = "round" +``` + +``` cpp +const auto data = toml::parse("fruit.toml"); +const auto& fruit = toml::find(data, "fruit"); +const auto name = toml::find(fruit, "name"); + +const auto& physical = toml::find(fruit, "physical"); +const auto color = toml::find(physical, "color"); +const auto shape = toml::find(physical, "shape"); +``` + +Here, variable `fruit` is a `toml::value` and can be used as the first argument +of `toml::find`. + +Second, you can pass as many arguments as the number of subtables to `toml::find`. + +```cpp +const auto data = toml::parse("fruit.toml"); +const auto color = toml::find(data, "fruit", "physical", "color"); +const auto shape = toml::find(data, "fruit", "physical", "shape"); +``` + +### Finding a value in an array + +You can find n-th value in an array by `toml::find`. + +```toml +values = ["foo", "bar", "baz"] +``` + +``` cpp +const auto data = toml::parse("sample.toml"); +const auto values = toml::find(data, "values"); +const auto bar = toml::find(values, 1); +``` + +`toml::find` can also search array recursively. + +```cpp +const auto data = toml::parse("fruit.toml"); +const auto bar = toml::find(data, "values", 1); +``` + +Before calling `toml::find`, you can check if a value corresponding to a key +exists. You can use both `bool toml::value::contains(const key&) const` and +`std::size_t toml::value::count(const key&) const`. Those behaves like the +`std::map::contains` and `std::map::count`. + +```cpp +const auto data = toml::parse("fruit.toml"); +if(data.contains("fruit") && data.at("fruit").count("physical") != 0) +{ + // ... +} +``` + +### In case of error + +If the value does not exist, `toml::find` throws `std::out_of_range` with the +location of the table. + +```console +terminate called after throwing an instance of 'std::out_of_range' + what(): [error] key "answer" not found + --> example.toml + 6 | [tab] + | ~~~~~ in this table +``` + +---- + +If the specified type differs from the actual value contained, it throws +`toml::type_error` that inherits `std::exception`. + +Similar to the case of syntax error, toml11 also displays clean error messages. +The error message when you choose `int` to get `string` value would be like this. + +```console +terminate called after throwing an instance of 'toml::type_error' + what(): [error] toml::value bad_cast to integer + --> example.toml + 3 | title = "TOML Example" + | ~~~~~~~~~~~~~~ the actual type is string +``` + +**NOTE**: In order to show this kind of error message, all the toml values have +a pointer to represent its range in a file. The entire contents of a file is +shared by `toml::value`s and remains on the heap memory. It is recommended to +destruct all the `toml::value` classes after configuring your application +if you have a large TOML file compared to the memory resource. + +### Dotted keys + +TOML v0.5.0 has a new feature named "dotted keys". +You can chain keys to represent the structure of the data. + +```toml +physical.color = "orange" +physical.shape = "round" +``` + +This is equivalent to the following. + +```toml +[physical] +color = "orange" +shape = "round" +``` + +You can get both of the above tables with the same c++ code. + +```cpp +const auto physical = toml::find(data, "physical"); +const auto color = toml::find(physical, "color"); +``` + +The following code does not work for the above toml file. + +```cpp +// XXX this does not work! +const auto color = toml::find(data, "physical.color"); +``` + +The above code works with the following toml file. + +```toml +"physical.color" = "orange" +# equivalent to {"physical.color": "orange"}, +# NOT {"physical": {"color": "orange"}}. +``` + + +## Casting a toml value + +### `toml::get` + +`toml::parse` returns `toml::value`. `toml::value` is a union type that can +contain one of the following types. + +- `toml::boolean` (`bool`) +- `toml::integer` (`std::int64_t`) +- `toml::floating` (`double`) +- `toml::string` (a type convertible to std::string) +- `toml::local_date` +- `toml::local_time` +- `toml::local_datetime` +- `toml::offset_datetime` +- `toml::array` (by default, `std::vector`) + - It depends. See [customizing containers](#customizing-containers) for detail. +- `toml::table` (by default, `std::unordered_map`) + - It depends. See [customizing containers](#customizing-containers) for detail. + +To get a value inside, you can use `toml::get()`. The usage is the same as +`toml::find` (actually, `toml::find` internally uses `toml::get` after casting +a value to `toml::table`). + +``` cpp +const toml::value data = toml::parse("sample.toml"); +const toml::value answer_ = toml::get(data).at("answer"); +const std::int64_t answer = toml::get(answer_); +``` + +When you pass an exact TOML type that does not require type conversion, +`toml::get` returns a reference through which you can modify the content +(if the `toml::value` is `const`, it returns `const` reference). + +```cpp +toml::value data = toml::parse("sample.toml"); +toml::value answer_ = toml::get(data).at("answer"); +toml::integer& answer = toml::get(answer_); +answer = 6 * 9; // write to data.answer. now `answer_` contains 54. +``` + +If the specified type requires conversion, you can't take a reference to the value. +See also [underlying types](#underlying-types). + +It also throws a `toml::type_error` if the type differs. + +### `as_xxx` + +You can also use a member function to cast a value. + +```cpp +const std::int64_t answer = data.as_table().at("answer").as_integer(); +``` + +It also throws a `toml::type_error` if the type differs. If you are sure that +the value `v` contains a value of the specified type, you can suppress checking +by passing `std::nothrow`. + +```cpp +const auto& answer = data.as_table().at("answer"); +if(answer.is_integer() && answer.as_integer(std::nothrow) == 42) +{ + std::cout << "value is 42" << std::endl; +} +``` + +If `std::nothrow` is passed, the functions are marked as noexcept. + +By casting a `toml::value` into an array or a table, you can iterate over the +elements. + +```cpp +const auto data = toml::parse("example.toml"); +std::cout << "keys in the top-level table are the following: \n"; +for(const auto& [k, v] : data.as_table()) +{ + std::cout << k << '\n'; +} + +const auto& fruits = toml::find(data, "fruits"); +for(const auto& v : fruits.as_array()) +{ + std::cout << toml::find(v, "name") << '\n'; +} +``` + +The full list of the functions is below. + +```cpp +namespace toml { +class value { + // ... + const boolean& as_boolean() const&; + const integer& as_integer() const&; + const floating& as_floating() const&; + const string& as_string() const&; + const offset_datetime& as_offset_datetime() const&; + const local_datetime& as_local_datetime() const&; + const local_date& as_local_date() const&; + const local_time& as_local_time() const&; + const array& as_array() const&; + const table& as_table() const&; + // -------------------------------------------------------- + // non-const version + boolean& as_boolean() &; + // ditto... + // -------------------------------------------------------- + // rvalue version + boolean&& as_boolean() &&; + // ditto... + + // -------------------------------------------------------- + // noexcept versions ... + const boolean& as_boolean(const std::nothrow_t&) const& noexcept; + boolean& as_boolean(const std::nothrow_t&) & noexcept; + boolean&& as_boolean(const std::nothrow_t&) && noexcept; + // ditto... +}; +} // toml +``` + +### `at()` + +You can access to the element of a table and an array by `toml::basic_value::at`. + +```cpp +const toml::value v{1,2,3,4,5}; +std::cout << v.at(2).as_integer() << std::endl; // 3 + +const toml::value v{{"foo", 42}, {"bar", 3.14}}; +std::cout << v.at("foo").as_integer() << std::endl; // 42 +``` + +If an invalid key (integer for a table, string for an array), it throws +`toml::type_error` for the conversion. If the provided key is out-of-range, +it throws `std::out_of_range`. + +Note that, although `std::string` has `at()` member function, `toml::value::at` +throws if the contained type is a string. Because `std::string` does not +contain `toml::value`. + +### `operator[]` + +You can also access to the element of a table and an array by +`toml::basic_value::operator[]`. + +```cpp +const toml::value v{1,2,3,4,5}; +std::cout << v[2].as_integer() << std::endl; // 3 + +const toml::value v{{"foo", 42}, {"bar", 3.14}}; +std::cout << v["foo"].as_integer() << std::endl; // 42 +``` + +When you access to a `toml::value` that is not initialized yet via +`operator[](const std::string&)`, the `toml::value` will be a table, +just like the `std::map`. + +```cpp +toml::value v; // not initialized as a table. +v["foo"] = 42; // OK. `v` will be a table. +``` + +Contrary, if you access to a `toml::value` that contains an array via `operator[]`, +it does not check anything. It converts `toml::value` without type check and then +access to the n-th element without boundary check, just like the `std::vector::operator[]`. + +```cpp +toml::value v; // not initialized as an array +v[2] = 42; // error! UB +``` + +Please make sure that the `toml::value` has an array inside when you access to +its element via `operator[]`. + +## Checking value type + +You can check the type of a value by `is_xxx` function. + +```cpp +const toml::value v = /* ... */; +if(v.is_integer()) +{ + std::cout << "value is an integer" << std::endl; +} +``` + +The complete list of the functions is below. + +```cpp +namespace toml { +class value { + // ... + bool is_boolean() const noexcept; + bool is_integer() const noexcept; + bool is_floating() const noexcept; + bool is_string() const noexcept; + bool is_offset_datetime() const noexcept; + bool is_local_datetime() const noexcept; + bool is_local_date() const noexcept; + bool is_local_time() const noexcept; + bool is_array() const noexcept; + bool is_table() const noexcept; + bool is_uninitialized() const noexcept; + // ... +}; +} // toml +``` + +Also, you can get `enum class value_t` from `toml::value::type()`. + +```cpp +switch(data.at("something").type()) +{ + case toml::value_t::integer: /*do some stuff*/ ; break; + case toml::value_t::floating: /*do some stuff*/ ; break; + case toml::value_t::string : /*do some stuff*/ ; break; + default : throw std::runtime_error( + "unexpected type : " + toml::stringize(data.at("something").type())); +} +``` + +The complete list of the `enum`s can be found in the section +[underlying types](#underlying-types). + +The `enum`s can be used as a parameter of `toml::value::is` function like the following. + +```cpp +toml::value v = /* ... */; +if(v.is(toml::value_t::boolean)) // ... +``` + +## More about conversion + +Since `toml::find` internally uses `toml::get`, all the following examples work +with both `toml::get` and `toml::find`. + +### Converting an array + +You can get any kind of `container` class from a `toml::array` +except for `map`-like classes. + +``` cpp +// # sample.toml +// numbers = [1,2,3] + +const auto numbers = toml::find(data, "numbers"); + +const auto vc = toml::get >(numbers); +const auto ls = toml::get >(numbers); +const auto dq = toml::get >(numbers); +const auto ar = toml::get>(numbers); +// if the size of data.at("numbers") is larger than that of std::array, +// it will throw toml::type_error because std::array is not resizable. +``` + +Surprisingly, you can convert `toml::array` into `std::pair` and `std::tuple`. + +```cpp +// numbers = [1,2,3] +const auto tp = toml::get>(numbers); +``` + +This functionality is helpful when you have a toml file like the following. + +```toml +array_of_arrays = [[1, 2, 3], ["foo", "bar", "baz"]] # toml allows this +``` + +What is the corresponding C++ type? +Obviously, it is a `std::pair` of `std::vector`s. + +```cpp +const auto array_of_arrays = toml::find(data, "array_of_arrays"); +const auto aofa = toml::get< + std::pair, std::vector> + >(array_of_arrays); +``` + +If you don't know the type of the elements, you can use `toml::array`, +which is a `std::vector` of `toml::value`, instead. + +```cpp +const auto a_of_a = toml::get(array_of_arrays); +const auto first = toml::get>(a_of_a.at(0)); +``` + +You can change the implementation of `toml::array` with `std::deque` or some +other array-like container. See [Customizing containers](#customizing-containers) +for detail. + +### Converting a table + +When all the values of the table have the same type, toml11 allows you to +convert a `toml::table` to a `map` that contains the convertible type. + +```toml +[tab] +key1 = "foo" # all the values are +key2 = "bar" # toml String +``` + +```cpp +const auto data = toml::parse("sample.toml"); +const auto tab = toml::find>(data, "tab"); +std::cout << tab["key1"] << std::endl; // foo +std::cout << tab["key2"] << std::endl; // bar +``` + +But since `toml::table` is just an alias of `std::unordered_map`, +normally you don't need to convert it because it has all the functionalities that +`std::unordered_map` has (e.g. `operator[]`, `count`, and `find`). In most cases +`toml::table` is sufficient. + +```cpp +toml::table tab = toml::get(data); +if(data.count("title") != 0) +{ + data["title"] = std::string("TOML example"); +} +``` + +You can change the implementation of `toml::table` with `std::map` or some +other map-like container. See [Customizing containers](#customizing-containers) +for detail. + +### Getting an array of tables + +An array of tables is just an array of tables. +You can get it in completely the same way as the other arrays and tables. + +```toml +# sample.toml +array_of_inline_tables = [{key = "value1"}, {key = "value2"}, {key = "value3"}] + +[[array_of_tables]] +key = "value4" +[[array_of_tables]] +key = "value5" +[[array_of_tables]] +key = "value6" +``` + +```cpp +const auto data = toml::parse("sample.toml"); +const auto aot1 = toml::find>(data, "array_of_inline_tables"); +const auto aot2 = toml::find>(data, "array_of_tables"); +``` + +### Cost of conversion + +Although conversion through `toml::(get|find)` is convenient, it has additional +copy-cost because it copies data contained in `toml::value` to the +user-specified type. Of course in some cases this overhead is not ignorable. + +```cpp +// the following code constructs a std::vector. +// it requires heap allocation for vector and element conversion. +const auto array = toml::find>(data, "foo"); +``` + +By passing the exact types, `toml::get` returns reference that has no overhead. + +``` cpp +const auto& tab = toml::find(data, "tab"); +const auto& numbers = toml::find(data, "numbers"); +``` + +Also, `as_xxx` are zero-overhead because they always return a reference. + +``` cpp +const auto& tab = toml::find(data, "tab" ).as_table(); +const auto& numbers = toml::find(data, "numbers").as_array(); +``` + +In this case you need to call `toml::get` each time you access to +the element of `toml::array` because `toml::array` is an array of `toml::value`. + +```cpp +const auto& num0 = toml::get(numbers.at(0)); +const auto& num1 = toml::get(numbers.at(1)); +const auto& num2 = toml::get(numbers.at(2)); +``` + +### Converting datetime and its variants + +TOML v0.5.0 has 4 different datetime objects, `local_date`, `local_time`, +`local_datetime`, and `offset_datetime`. + +Since `local_date`, `local_datetime`, and `offset_datetime` represent a time +point, you can convert them to `std::chrono::system_clock::time_point`. + +Contrary, `local_time` does not represents a time point because they lack a +date information, but it can be converted to `std::chrono::duration` that +represents a duration from the beginning of the day, `00:00:00.000`. + +```toml +# sample.toml +date = 2018-12-23 +time = 12:30:00 +l_dt = 2018-12-23T12:30:00 +o_dt = 2018-12-23T12:30:00+09:30 +``` + +```cpp +const auto data = toml::parse("sample.toml"); + +const auto date = toml::get(data.at("date")); +const auto l_dt = toml::get(data.at("l_dt")); +const auto o_dt = toml::get(data.at("o_dt")); + +const auto time = toml::get(data.at("time")); // 12 * 60 + 30 min +``` + +`local_date` and `local_datetime` are assumed to be in the local timezone when +they are converted into `time_point`. On the other hand, `offset_datetime` only +uses the offset part of the data and it does not take local timezone into account. + +To contain datetime data, toml11 defines its own datetime types. +For more detail, you can see the definitions in [toml/datetime.hpp](toml/datetime.hpp). + +## Getting with a fallback + +`toml::find_or` returns a default value if the value is not found or has a +different type. + +```cpp +const auto data = toml::parse("example.toml"); +const auto num = toml::find_or(data, "num", 42); +``` + +Also, `toml::get_or` returns a default value if `toml::get` failed. + +```cpp +toml::value v("foo"); // v contains String +const int value = toml::get_or(v, 42); // conversion fails. it returns 42. +``` + +These functions automatically deduce what type you want to get +from the default value you passed. + +To get a reference through this function, take care about the default value. + +```cpp +toml::value v("foo"); // v contains String +toml::integer& i = toml::get_or(v, 42); // does not work because binding `42` + // to `integer&` is invalid +toml::integer opt = 42; +toml::integer& i = toml::get_or(v, opt); // this works. +``` + +## Expecting conversion + +By using `toml::expect`, you will get your expected value or an error message +without throwing `toml::type_error`. + +```cpp +const auto value = toml::expect(data.at("title")); +if(value.is_ok()) { + std::cout << value.unwrap() << std::endl; +} else { + std::cout << value.unwrap_err() << std::endl; +} +``` + +Also, you can pass a function object to modify the expected value. + +```cpp +const auto value = toml::expect(data.at("number")) + .map(// function that receives expected type (here, int) + [](const int number) -> double { + return number * 1.5 + 1.0; + }).unwrap_or(/*default value =*/ 3.14); +``` + +## Visiting a toml::value + +toml11 provides `toml::visit` to apply a function to `toml::value` in the +same way as `std::variant`. + +```cpp +const toml::value v(3.14); +toml::visit([](const auto& val) -> void { + std::cout << val << std::endl; + }, v); +``` + +The function object that would be passed to `toml::visit` must be able to +recieve all the possible TOML types. Also, the result types should be the same +each other. + +## Constructing a toml::value + +`toml::value` can be constructed in various ways. + +```cpp +toml::value v(true); // boolean +toml::value v(42); // integer +toml::value v(3.14); // floating +toml::value v("foobar"); // string +toml::value v(toml::local_date(2019, toml::month_t::Apr, 1)); // date +toml::value v{1, 2, 3, 4, 5}; // array +toml::value v{{"foo", 42}, {"bar", 3.14}, {"baz", "qux"}}; // table +``` + +When constructing a string, you can choose to use either literal or basic string. +By default, it will be a basic string. + +```cpp +toml::value v("foobar", toml::string_t::basic ); +toml::value v("foobar", toml::string_t::literal); +``` + +Datetime objects can be constructed from `std::tm` and +`std::chrono::system_clock::time_point`. But you need to specify what type +you use to avoid ambiguity. + +```cpp +const auto now = std::chrono::system_clock::now(); +toml::value v(toml::local_date(now)); +toml::value v(toml::local_datetime(now)); +toml::value v(toml::offset_datetime(now)); +``` + +Since local time is not equivalent to a time point, because it lacks date +information, it will be constructed from `std::chrono::duration`. + +```cpp +toml::value v(toml::local_time(std::chrono::hours(10))); +``` + +You can construct an array object not only from `initializer_list`, but also +from STL containers. In that case, the element type must be convertible to +`toml::value`. + +```cpp +std::vector vec{1,2,3,4,5}; +toml::value v(vec); +``` + +When you construct an array value, all the elements of `initializer_list` +must be convertible into `toml::value`. + +If a `toml::value` has an array, you can `push_back` an element in it. + +```cpp +toml::value v{1,2,3,4,5}; +v.push_back(6); +``` + +`emplace_back` also works. + +## Preserving comments + +After toml11 v3, you can choose whether comments are preserved or not. + +```cpp +const auto data1 = toml::parse("example.toml"); +const auto data2 = toml::parse("example.toml"); +``` + +Comments related to a value can be obtained by `toml::value::comments()`. +The return value has the same interface as `std::vector`. + +```cpp +const auto& com = v.comments(); +for(const auto& c : com) +{ + std::cout << c << std::endl; +} +``` + +Comments just before and just after (within the same line) a value are kept in a value. + +```toml +# this is a comment for v1. +v1 = "foo" + +v2 = "bar" # this is a comment for v2. +# Note that this comment is NOT a comment for v2. + +# this comment is not related to any value +# because there are empty lines between v3. +# this comment will be ignored even if you set `preserve_comments`. + +# this is a comment for v3 +# this is also a comment for v3. +v3 = "baz" # ditto. +``` + +Each comment line becomes one element of a `std::vector`. + +Hash signs will be removed, but spaces after hash sign will not be removed. + +```cpp +v1.comments().at(0) == " this is a comment for v1."s; + +v2.comments().at(1) == " this is a comment for v1."s; + +v3.comments().at(0) == " this is a comment for v3."s; +v3.comments().at(1) == " this is also a comment for v3."s; +v3.comments().at(2) == " ditto."s; +``` + +Note that a comment just after an opening brace of an array will not be a +comment for the array. + +```toml +# this is a comment for a. +a = [ # this is not a comment for a. this will be ignored. + 1, 2, 3, + # this is a comment for `42`. + 42, # this is also a comment for `42`. + 5 +] # this is a comment for a. +``` + +You can also append and modify comments. +The interfaces are the same as `std::vector`. + +```cpp +toml::basic_value v(42); +v.comments().push_back(" add this comment."); +// # add this comment. +// i = 42 +``` + +Also, you can pass a `std::vector` when constructing a +`toml::basic_value`. + +```cpp +std::vector comments{"comment 1", "comment 2"}; +const toml::basic_value v1(42, std::move(comments)); +const toml::basic_value v2(42, {"comment 1", "comment 2"}); +``` + +When `toml::discard_comments` is chosen, comments will not be contained in a value. +`value::comments()` will always be kept empty. +All the modification on comments would be ignored. +All the element access in a `discard_comments` causes the same error as accessing +an element of an empty `std::vector`. + +The comments will also be serialized. If comments exist, those comments will be +added just before the values. + +__NOTE__: Result types from `toml::parse(...)` and +`toml::parse(...)` are different. + +## Customizing containers + +Actually, `toml::basic_value` has 3 template arguments. + +```cpp +template class Table = std::unordered_map, + template class Array = std::vector> +class basic_value; +``` + +This enables you to change the containers used inside. E.g. you can use +`std::map` to contain a table object instead of `std::unordered_map`. +And also can use `std::deque` as a array object instead of `std::vector`. + +You can set these parameters while calling `toml::parse` function. + +```cpp +const auto data = toml::parse< + toml::preserve_comments, std::map, std::deque + >("example.toml"); +``` + +Needless to say, the result types from `toml::parse(...)` and +`toml::parse(...)` are different (unless you specify the same +types as default). + +Note that, since `toml::table` and `toml::array` is an alias for a table and an +array of a default `toml::value`, so it is different from the types actually +contained in a `toml::basic_value` when you customize containers. +To get the actual type in a generic way, use +`typename toml::basic_type::table_type` and +`typename toml::basic_type::array_type`. + +## TOML literal + +toml11 supports `"..."_toml` literal. +It accept both a bare value and a file content. + +```cpp +using namespace toml::literals::toml_literals; + +// `_toml` can convert a bare value without key +const toml::value v = u8"0xDEADBEEF"_toml; +// v is an Integer value containing 0xDEADBEEF. + +// raw string literal (`R"(...)"` is useful for this purpose) +const toml::value t = u8R"( + title = "this is TOML literal" + [table] + key = "value" +)"_toml; +// the literal will be parsed and the result will be contained in t +``` + +The literal function is defined in the same way as the standard library literals +such as `std::literals::string_literals::operator""s`. + +```cpp +namespace toml +{ +inline namespace literals +{ +inline namespace toml_literals +{ +toml::value operator"" _toml(const char* str, std::size_t len); +} // toml_literals +} // literals +} // toml +``` + +Access to the operator can be gained with `using namespace toml::literals;`, +`using namespace toml::toml_literals`, and `using namespace toml::literals::toml_literals`. + +Note that a key that is composed only of digits is allowed in TOML. +And, unlike the file parser, toml-literal allows a bare value without a key. +Thus it is difficult to distinguish arrays having integers and definitions of +tables that are named as digits. +Currently, literal `[1]` becomes a table named "1". +To ensure a literal to be considered as an array with one element, you need to +add a comma after the first element (like `[1,]`). + +```cpp +"[1,2,3]"_toml; // This is an array +"[table]"_toml; // This is a table that has an empty table named "table" inside. +"[[1,2,3]]"_toml; // This is an array of arrays +"[[table]]"_toml; // This is a table that has an array of tables inside. + +"[[1]]"_toml; // This literal is ambiguous. + // Currently, it becomes a table that has array of table "1". +"1 = [{}]"_toml; // This is a table that has an array of table named 1. +"[[1,]]"_toml; // This is an array of arrays. +"[[1],]"_toml; // ditto. +``` + +NOTE: `_toml` literal returns a `toml::value` that does not have comments. + +## Conversion between toml value and arbitrary types + +You can also use `toml::get` and other related functions with the types +you defined after you implement a way to convert it. + +```cpp +namespace ext +{ +struct foo +{ + int a; + double b; + std::string c; +}; +} // ext + +const auto data = toml::parse("example.toml"); + +// to do this +const foo f = toml::find(data, "foo"); +``` + +There are 3 ways to use `toml::get` with the types that you defined. + +The first one is to implement `from_toml(const toml::value&)` member function. + +```cpp +namespace ext +{ +struct foo +{ + int a; + double b; + std::string c; + + void from_toml(const toml::value& v) + { + this->a = toml::find(v, "a"); + this->b = toml::find(v, "b"); + this->c = toml::find(v, "c"); + return; + } +}; +} // ext +``` + +In this way, because `toml::get` first constructs `foo` without arguments, +the type should be default-constructible. + +The second is to implement `constructor(const toml::value&)`. + +```cpp +namespace ext +{ +struct foo +{ + explicit foo(const toml::value& v) + : a(toml::find(v, "a")), b(toml::find(v, "b")), + c(toml::find(v, "c")) + {} + + int a; + double b; + std::string c; +}; +} // ext +``` + +Note that implicit default constructor declaration will be suppressed +when a constructor is defined. If you want to use the struct (here, `foo`) +in a container (e.g. `std::vector`), you may need to define default +constructor explicitly. + +The third is to implement specialization of `toml::from` for your type. + +```cpp +namespace ext +{ +struct foo +{ + int a; + double b; + std::string c; +}; +} // ext + +namespace toml +{ +template<> +struct from +{ + static ext::foo from_toml(const value& v) + { + ext::foo f; + f.a = find(v, "a"); + f.b = find(v, "b"); + f.c = find(v, "c"); + return f; + } +}; +} // toml +``` + +In this way, since the conversion function is defined outside of the class, +you can add conversion between `toml::value` and classes defined in another library. + +Note that you cannot implement both of the functions because the overload +resolution of `toml::get` will be ambiguous. + +If you want to convert any versions of `toml::basic_value`, +you need to templatize the conversion function as follows. + +```cpp +struct foo +{ + template class M, template class A> + void from_toml(const toml::basic_value& v) + { + this->a = toml::find(v, "a"); + this->b = toml::find(v, "b"); + this->c = toml::find(v, "c"); + return; + } +}; +// or +namespace toml +{ +template<> +struct from +{ + template class M, template class A> + static ext::foo from_toml(const basic_value& v) + { + ext::foo f; + f.a = find(v, "a"); + f.b = find(v, "b"); + f.c = find(v, "c"); + return f; + } +}; +} // toml +``` + +---- + +The opposite direction is also supported in a similar way. You can directly +pass your type to `toml::value`'s constructor by introducing `into_toml` or +`toml::into`. + +```cpp +namespace ext +{ +struct foo +{ + int a; + double b; + std::string c; + + toml::value into_toml() const // you need to mark it const. + { + return toml::value{{"a", this->a}, {"b", this->b}, {"c", this->c}}; + } +}; +} // ext + +ext::foo f{42, 3.14, "foobar"}; +toml::value v(f); +``` + +The definition of `toml::into` is similar to `toml::from`. + +```cpp +namespace ext +{ +struct foo +{ + int a; + double b; + std::string c; +}; +} // ext + +namespace toml +{ +template<> +struct into +{ + static toml::value into_toml(const ext::foo& f) + { + return toml::value{{"a", f.a}, {"b", f.b}, {"c", f.c}}; + } +}; +} // toml + +ext::foo f{42, 3.14, "foobar"}; +toml::value v(f); +``` + +Any type that can be converted to `toml::value`, e.g. `int`, `toml::table` and +`toml::array` are okay to return from `into_toml`. + +You can also return a custom `toml::basic_value` from `toml::into`. + +```cpp +namespace toml +{ +template<> +struct into +{ + static toml::basic_value into_toml(const ext::foo& f) + { + toml::basic_value v{{"a", f.a}, {"b", f.b}, {"c", f.c}}; + v.comments().push_back(" comment"); + return v; + } +}; +} // toml +``` + +But note that, if this `basic_value` would be assigned into other `toml::value` +that discards `comments`, the comments would be dropped. + +### Macro to automatically define conversion functions + +There is a helper macro that automatically generates conversion functions `from` and `into` for a simple struct. + +```cpp +namespace foo +{ +struct Foo +{ + std::string s; + double d; + int i; +}; +} // foo + +TOML11_DEFINE_CONVERSION_NON_INTRUSIVE(foo::Foo, s, d, i) + +int main() +{ + const auto file = toml::parse("example.toml"); + auto f = toml::find(file, "foo"); +} +``` + +And then you can use `toml::find(file, "foo");` + +**Note** that, because of a slight difference in implementation of preprocessor between gcc/clang and MSVC, [you need to define `/Zc:preprocessor`](https://github.com/ToruNiina/toml11/issues/139#issuecomment-803683682) to use it in MSVC (Thank you @glebm !). + +## Formatting user-defined error messages + +When you encounter an error after you read the toml value, you may want to +show the error with the value. + +toml11 provides you a function that formats user-defined error message with +related values. With a code like the following, + +```cpp +const auto value = toml::find(data, "num"); +if(value < 0) +{ + std::cerr << toml::format_error("[error] value should be positive", + data.at("num"), "positive number required") + << std::endl; +} +``` + +you will get an error message like this. + +```console +[error] value should be positive + --> example.toml + 3 | num = -42 + | ~~~ positive number required +``` + +When you pass two values to `toml::format_error`, + +```cpp +const auto min = toml::find(range, "min"); +const auto max = toml::find(range, "max"); +if(max < min) +{ + std::cerr << toml::format_error("[error] max should be larger than min", + data.at("min"), "minimum number here", + data.at("max"), "maximum number here"); + << std::endl; +} +``` + +you will get an error message like this. + +```console +[error] max should be larger than min + --> example.toml + 3 | min = 54 + | ~~ minimum number here + ... + 4 | max = 42 + | ~~ maximum number here +``` + +You can print hints at the end of the message. + +```cpp +std::vector hints; +hints.push_back("positive number means n >= 0."); +hints.push_back("negative number is not positive."); +std::cerr << toml::format_error("[error] value should be positive", + data.at("num"), "positive number required", hints) + << std::endl; +``` + +```console +[error] value should be positive + --> example.toml + 2 | num = 42 + | ~~ positive number required + | +Hint: positive number means n >= 0. +Hint: negative number is not positive. +``` + +## Obtaining location information + +You can also format error messages in your own way by using `source_location`. + +```cpp +struct source_location +{ + std::uint_least32_t line() const noexcept; + std::uint_least32_t column() const noexcept; + std::uint_least32_t region() const noexcept; + std::string const& file_name() const noexcept; + std::string const& line_str() const noexcept; +}; +// +-- line() +--- length of the region (here, region() == 9) +// v .---+---. +// 12 | value = "foo bar" <- line_str() returns the line itself. +// ^-------- column() points here +``` + +You can get this by +```cpp +const toml::value v = /*...*/; +const toml::source_location loc = v.location(); +``` + +## Exceptions + +The following `exception` classes inherits `toml::exception` that inherits +`std::exception`. + +```cpp +namespace toml { +struct exception : public std::exception {/**/}; +struct syntax_error : public toml::exception {/**/}; +struct type_error : public toml::exception {/**/}; +struct internal_error : public toml::exception {/**/}; +} // toml +``` + +`toml::exception` has `toml::exception::location()` member function that returns +`toml::source_location`, in addition to `what()`. + +```cpp +namespace toml { +struct exception : public std::exception +{ + // ... + source_location const& location() const noexcept; +}; +} // toml +``` + +It represents where the error occurs. + +`syntax_error` will be thrown from `toml::parse` and `_toml` literal. +`type_error` will be thrown from `toml::get/find`, `toml::value::as_xxx()`, and +other functions that takes a content inside of `toml::value`. + +Note that, currently, from `toml::value::at()` and `toml::find(value, key)` +may throw an `std::out_of_range` that does not inherits `toml::exception`. + +Also, in some cases, most likely in the file open error, it will throw an +`std::runtime_error`. + +## Colorize Error Messages + +By defining `TOML11_COLORIZE_ERROR_MESSAGE`, the error messages from +`toml::parse` and `toml::find|get` will be colorized. By default, this feature +is turned off. + +With the following toml file taken from `toml-lang/toml/tests/hard_example.toml`, + +```toml +[error] +array = [ + "This might most likely happen in multiline arrays", + Like here, + "or here, + and here" + ] End of array comment, forgot the # +``` + +the error message would be like this. + +![error-message-1](https://github.com/ToruNiina/toml11/blob/misc/misc/toml11-err-msg-1.png) + +With the following, + +```toml +[error] +# array = [ +# "This might most likely happen in multiline arrays", +# Like here, +# "or here, +# and here" +# ] End of array comment, forgot the # +number = 3.14 pi <--again forgot the # +``` + +the error message would be like this. + +![error-message-2](https://github.com/ToruNiina/toml11/blob/misc/misc/toml11-err-msg-2.png) + +The message would be messy when it is written to a file, not a terminal because +it uses [ANSI escape code](https://en.wikipedia.org/wiki/ANSI_escape_code). + +Without `TOML11_COLORIZE_ERROR_MESSAGE`, you can still colorize user-defined +error message by passing `true` to the `toml::format_error` function. +If you define `TOML11_COLORIZE_ERROR_MESSAGE`, the value is `true` by default. +If not, the defalut value would be `false`. + +```cpp +std::cerr << toml::format_error("[error] value should be positive", + data.at("num"), "positive number required", + hints, /*colorize = */ true) << std::endl; +``` + +Note: It colorize `[error]` in red. That means that it detects `[error]` prefix +at the front of the error message. If there is no `[error]` prefix, +`format_error` adds it to the error message. + +## Serializing TOML data + +toml11 enables you to serialize data into toml format. + +```cpp +const toml::value data{{"foo", 42}, {"bar", "baz"}}; +std::cout << data << std::endl; +// bar = "baz" +// foo = 42 +``` + +toml11 automatically makes a small table and small array inline. +You can specify the width to make them inline by `std::setw` for streams. + +```cpp +const toml::value data{ + {"qux", {{"foo", 42}, {"bar", "baz"}}}, + {"quux", {"small", "array", "of", "strings"}}, + {"foobar", {"this", "array", "of", "strings", "is", "too", "long", + "to", "print", "into", "single", "line", "isn't", "it?"}}, +}; + +// the threshold becomes 80. +std::cout << std::setw(80) << data << std::endl; +// foobar = [ +// "this","array","of","strings","is","too","long","to","print","into", +// "single","line","isn't","it?", +// ] +// quux = ["small","array","of","strings"] +// qux = {bar="baz",foo=42} + + +// the width is 0. nothing become inline. +std::cout << std::setw(0) << data << std::endl; +// foobar = [ +// "this", +// ... (snip) +// "it?", +// ] +// quux = [ +// "small", +// "array", +// "of", +// "strings", +// ] +// [qux] +// bar = "baz" +// foo = 42 +``` + +It is recommended to set width before printing data. Some I/O functions changes +width to 0, and it makes all the stuff (including `toml::array`) multiline. +The resulting files becomes too long. + +To control the precision of floating point numbers, you need to pass +`std::setprecision` to stream. + +```cpp +const toml::value data{ + {"pi", 3.141592653589793}, + {"e", 2.718281828459045} +}; +std::cout << std::setprecision(17) << data << std::endl; +// e = 2.7182818284590451 +// pi = 3.1415926535897931 +std::cout << std::setprecision( 7) << data << std::endl; +// e = 2.718282 +// pi = 3.141593 +``` + +There is another way to format toml values, `toml::format()`. +It returns `std::string` that represents a value. + +```cpp +const toml::value v{{"a", 42}}; +const std::string fmt = toml::format(v); +// a = 42 +``` + +Note that since `toml::format` formats a value, the resulting string may lack +the key value. + +```cpp +const toml::value v{3.14}; +const std::string fmt = toml::format(v); +// 3.14 +``` + +To control the width and precision, `toml::format` receives optional second and +third arguments to set them. By default, the witdh is 80 and the precision is +`std::numeric_limits::max_digit10`. + +```cpp +const auto serial = toml::format(data, /*width = */ 0, /*prec = */ 17); +``` + +When you pass a comment-preserving-value, the comment will also be serialized. +An array or a table containing a value that has a comment would not be inlined. + +## Underlying types + +The toml types (can be used as `toml::*` in this library) and corresponding `enum` names are listed in the table below. + +| TOML type | underlying c++ type | enum class | +| -------------- | ---------------------------------- | -------------------------------- | +| Boolean | `bool` | `toml::value_t::boolean` | +| Integer | `std::int64_t` | `toml::value_t::integer` | +| Float | `double` | `toml::value_t::floating` | +| String | `toml::string` | `toml::value_t::string` | +| LocalDate | `toml::local_date` | `toml::value_t::local_date` | +| LocalTime | `toml::local_time` | `toml::value_t::local_time` | +| LocalDatetime | `toml::local_datetime` | `toml::value_t::local_datetime` | +| OffsetDatetime | `toml::offset_datetime` | `toml::value_t::offset_datetime` | +| Array | `array-like` | `toml::value_t::array` | +| Table | `map-like` | `toml::value_t::table` | + +`array-like` and `map-like` are the STL containers that works like a `std::vector` and +`std::unordered_map`, respectively. By default, `std::vector` and `std::unordered_map` +are used. See [Customizing containers](#customizing-containers) for detail. + +`toml::string` is effectively the same as `std::string` but has an additional +flag that represents a kind of a string, `string_t::basic` and `string_t::literal`. +Although `std::string` is not an exact toml type, still you can get a reference +that points to internal `std::string` by using `toml::get()` for convenience. +The most important difference between `std::string` and `toml::string` is that +`toml::string` will be formatted as a TOML string when outputed with `ostream`. +This feature is introduced to make it easy to write a custom serializer. + +`Datetime` variants are `struct` that are defined in this library. +Because `std::chrono::system_clock::time_point` is a __time point__, +not capable of representing a Local Time independent from a specific day. + +## Unreleased TOML features + +Since TOML v1.0.0-rc.1 has been released, those features are now activated by +default. We no longer need to define `TOML11_USE_UNRELEASED_FEATURES`. + +- Leading zeroes in exponent parts of floats are permitted. + - e.g. `1.0e+01`, `5e+05` + - [toml-lang/toml/PR/656](https://github.com/toml-lang/toml/pull/656) +- Allow raw tab characters in basic strings and multi-line basic strings. + - [toml-lang/toml/PR/627](https://github.com/toml-lang/toml/pull/627) +- Allow heterogeneous arrays + - [toml-lang/toml/PR/676](https://github.com/toml-lang/toml/pull/676) + +## Note about heterogeneous arrays + +Although `toml::parse` allows heterogeneous arrays, constructor of `toml::value` +does not. Here the reason is explained. + +```cpp +// this won't be compiled +toml::value v{ + "foo", 3.14, 42, {1,2,3,4,5}, {{"key", "value"}} +} +``` + +There is a workaround for this. By explicitly converting values into +`toml::value`, you can initialize `toml::value` with a heterogeneous array. +Also, you can first initialize a `toml::value` with an array and then +`push_back` into it. + +```cpp +// OK! +toml::value v{ + toml::value("foo"), toml::value(3.14), toml::value(42), + toml::value{1,2,3,4,5}, toml::value{{"key", "value"}} +} + +// OK! +toml::value v(toml::array{}); +v.push_back("foo"); +v.push_back(3.14); + +// OK! +toml::array a; +a.push_back("foo"); +a.push_back(3.14); +toml::value v(std::move(a)); +``` + +The reason why the first example is not allowed is the following. +Let's assume that you are initializing a `toml::value` with a table. + +```cpp + // # expecting TOML table. +toml::value v{ // [v] + {"answer", 42}, // answer = 42 + {"pi", 3.14}, // pi = 3.14 + {"foo", "bar"} // foo = "bar" +}; +``` + +This is indistinguishable from a (heterogeneous) TOML array definition. + +```toml +v = [ + ["answer", 42], + ["pi", 3.14], + ["foo", "bar"], +