https://github.com/peelonet/peelo-json
Minimal JSON parser for C++
https://github.com/peelonet/peelo-json
cpp-library header-only json json-parser
Last synced: 3 months ago
JSON representation
Minimal JSON parser for C++
- Host: GitHub
- URL: https://github.com/peelonet/peelo-json
- Owner: peelonet
- License: bsd-2-clause
- Created: 2024-11-28T22:14:42.000Z (over 1 year ago)
- Default Branch: main
- Last Pushed: 2024-11-30T12:21:44.000Z (over 1 year ago)
- Last Synced: 2025-03-31T14:18:31.591Z (over 1 year ago)
- Topics: cpp-library, header-only, json, json-parser
- Language: C++
- Homepage:
- Size: 314 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE.md
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README
# peelo-json
I recently stumbled across an [Hacker News post] that announced an
[alternative] to the widely used [nlohmann JSON] library for C++.
It gave me an idea to test how much work it would be to write a minimal [JSON]
parser library for C++ and this is the result.
I wanted to be as tiny as possible, not to include it's own UTF-8 decoder
(bring your own) and not to throw exceptions but use result type instead.
[Doxygen generated API documentation.][API]
[Hacker News Post]: https://news.ycombinator.com/item?id=42132533
[alternative]: https://github.com/jart/json.cpp
[nlohmann JSON]: https://github.com/nlohmann/json/
[JSON]: https://www.json.org
[API]: https://peelonet.github.io/peelo-json/index.html
## Dependencies
This library depends on another header only library called [peelo-result]. This
should be handled by [CMake].
[peelo-result]: https://github.com/peelonet/peelo-result
[CMake]: https://cmake.org
## Usage
### Parsing JSON
You can use `peelo::json::parse()` function to parse an Unicode string into
JSON value.
```cpp
#include
#include
int
main()
{
const auto result = peelo::json::parse(U"[1, 2, 3]");
if (result)
{
if (peelo::json::type_of(*result) == peelo::json::type::array)
{
const auto array = peelo::json::as(*result);
std::cout << "Given input produced an array." << std::endl;
std::cout << "It has " << array->elements().size() << " elements." << std::endl;
}
} else {
std::cout << "Parsing error occurred: " << result.error().what() << std::endl;
}
}
```
If you want specicially to parse an JSON object, you can use
`peelo::json::parse_object()` function instead, which does not accept any
other input than an object.
### Formatting JSON
To format an JSON value returned by `peelo::json::parse()` function into an
ASCII string, you can use `peelo::json::format()` function.
```cpp
#include
#include
int
main()
{
if (const auto result = peelo::json::parse(U"{\"foo\": \"bar\"}"))
{
// This should output `{"foo":"bar"}` to standard output.
std::cout << peelo::json::format(*value) << std::endl;
}
}
```
## TODO
- Pretty print option for formatting JSON values.
- `std::u32string` version of `format()` function.