C++_解码Toml文件-Aet

Bingliaolong 2020-08-14 08:14 Aet | 隐藏边栏 | 抢沙发 | 2 0

文章评分 1 次，平均分 5.0 ：

概述

本文介绍的关于toml就C++工程中的使用以及语法细节，皆基于下面这个版本的相关实现：
https://github.com/ToruNiina/toml11.git
本文介绍的关于工程布局参考个人习惯以作示例。

添加模块

将下载下来的工程中的toml文件夹以及toml.hpp文件打包放到用于存放第三方库的文件目录Third下，结构如下所示：

Project
- Project.cpp
Bin
Conf
- test.toml
Debug
Include
Src
Third
- toml
  - toml
  - toml.hpp
- others
Project.sln

在项目工程中引用

#include <iostream>

#include "../Third/toml/toml.hpp"

using namespace std;

int main()

{

cout << "hello" << endl;

return 0;

}

解码文件

#include <iostream>

#include "../Third/toml/toml.hpp"

using namespace std;

int main()

{

const auto data = toml::parse("test.toml");

return 0;

}

获取值

# test.toml

answer = 42

pi = 3.14

numbers = [1,2,3]

time = 1979-05-27T07:32:00Z

[fruit]

name = "apple"

[fruit.physical]

color = "red"

shape = "round"

values = ["foo", "bar", "baz"]

#include <iostream>

#include "../Third/toml/toml.hpp"

using namespace std;

int main()

{

const auto data = toml::parse("test.toml");

const auto answer = toml::find<std::int64_t>(data, "answer");

const auto pi = toml::find<double>(data, "pi");

const auto numbers = toml::find<std::vector<int>>(data, "numbers");

const auto timepoint = toml::find<std::chrono::system_clock::time_point>(data, "time");

//获取表中数据

const auto& fruit = toml::find(data, "fruit");

const auto name = toml::find<std::string>(fruit, "name");

const auto& physical = toml::find(fruit, "physical");

const auto color = toml::find<std::string>(physical, "color");

const auto shape = toml::find<std::string>(physical, "shape");

//或者

const auto color1 = toml::find<std::string>(data, "fruit", "physical", "color");

const auto shape1 = toml::find<std::string>(data, "fruit", "physical", "shape");

//获取数组中数据

const auto values = toml::find(data, "values");

const auto bar = toml::find<std::string>(values, 1);

//或者

const auto bar = toml::find<std::string>(data, "values", 1);

//检查是否存在与键对应的值

if(data.contains("fruit") && data.at("fruit").count("physical") != 0)

{

// ...

}

return 0;

}

虚线键

physical.color = "orange"

physical.shape = "round"

# 等价于

[physical]

color = "orange"

shape = "round"

//获取值

const auto physical = toml::find(data, "physical");

const auto color = toml::find<std::string>(physical, "color");

转换值

const toml :: value data = toml :: parse（“ test.toml ”）;

const toml :: value answer_ = toml :: get <toml :: table>（data）.at（“ answer ”）;

const std :: int64_t answer = toml :: get <std :: int64_t >（answer_）;

toml::value answer_ = toml::get<toml::table >(data).at("answer");

toml::integer& answer = toml::get<toml::integer>(answer_);

answer = 6 * 9; // write to data.answer. now `answer_` contains 54.

const auto data = toml::parse("test.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<std::string>(v, "name") << '\n';

}

下标操作

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

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

toml::value v; // not initialized as a table.

v["foo"] = 42; // OK. `v` will be a table.

检查值

const toml::value v = /* ... */;

if(v.is_integer())

{

std::cout << "value is an integer" << std::endl;

}

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

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()));

}

转换数组

// # test.toml

// numbers = [1,2,3]

const auto numbers = toml::find(data, "numbers");

const auto vc = toml::get<std::vector<int> >(numbers);

const auto ls = toml::get<std::list<int> >(numbers);

const auto dq = toml::get<std::deque<int> >(numbers);

const auto ar = toml::get<std::array<int, 3>>(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.

1 2	// numbers = [1,2,3] const auto tp = toml::get<std::tuple<short, int, unsigned int>>(numbers);

array_of_arrays = [[1, 2, 3], ["foo", "bar", "baz"]] # toml allows this

const auto array_of_arrays = toml::find(data, "array_of_arrays");

const auto aofa = toml::get<std::pair<std::vector<int>, std::vector<std::string>>>(array_of_arrays);

1 2	const auto a_of_a = toml::get<toml::array>(array_of_arrays); const auto first = toml::get<std::vector<int>>(a_of_a.at(0));

转换表

[tab]

key1 = "foo" # all the values are

key2 = "bar" # toml String

const auto data = toml::parse("sample.toml");

const auto tab = toml::find<std::map<std::string, std::string>>(data, "tab");

std::cout << tab["key1"] << std::endl; // foo

std::cout << tab["key2"] << std::endl; // bar

# 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"

const auto data = toml::parse("sample.toml");

const auto aot1 = toml::find<std::vector<toml::table>>(data, "array_of_inline_tables");

const auto aot2 = toml::find<std::vector<toml::table>>(data, "array_of_tables");

概述
添加模块
解码文件
获取值
虚线键
转换值
下标操作
检查值
转换数组
转换表

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Bingliaolong 关注：0 粉丝：0 最后编辑于：2021-11-20

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概述

添加模块

解码文件

获取值

虚线键

转换值

下标操作

检查值

转换数组

转换表

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