rana is a C++ library for reading and writing JavaScript Object Notation (JSON) files with an emphasis on ease-of-use.

To try out the program, there are two options:

• Download the latest release.
• Clone the repository: git clone https://github.com/tfussell/rana.

To start using rana in your project, just include rana.hpp. All of the objects and functions are in the namespace rana. You don't need to compile or link anything.

Load a JSON file like this:

rana::value json = rana::from_file("file.json");

You can treat this object much like an object in JavaScript:

//Keyed access
int item1 = json["item1"];
bool item2 = json["item2"];
//Indexed access
std::string item3 = json[3];
float item4 = json[4];

If your JSON object contains an array, you can iterate over all of the values:

for(const auto &element : json[5].iter_array())
{
    std::cout << element << std::endl;
}

Likewise for an object:

for(const auto &member : json[5].iter_object())
{
    std::cout << member.first << " " << member.second << std::endl;
}

You can append an item to your array:

rana::value a = rana::value::array;
a.append(3);
a.append(false);
// Convenience notation for the same
rana::value a = rana::value::array(3)(false);

Finally, stringify your object:

std::cout << rana::to_string(a) << std::endl;

This is assuming we have an example file, file.json, which looks like this:

{
  "item1" : 42,
  "item2" : false,
  "item3" : "this is a string",
  "item4" : 3.141592,
  "item5" : [0, 1, 2],
}

• Config files - JSON is a convenient, concise, and readable format for storing configuration options. rana will allow you to quickly read and write configuration files.
• Interoperability - There are JSON interfaces for all of the major languages. With rana you transfer data between processes and systems without some of the complications of full serialization.
• Flat file databases - You can use rana for JSON-based databases that are more compact than CSV or XML. This method is also easier for humans to read and modify by hand.

• Simple - 3 objects, header-only
• Fast - speed similar to other C++ JSON libraries in built-in benchmarks
• Unicode support - strings are internally stored as UTF8. They can be read from and written to ascii, latin1, utf8, utf16, and utf32.
• No external dependencies - rana doesn't require boost or parser generators--only the STL
• Windows/Linux/OS X compability - rana is regularly built on and passes all tests in the three major operating systems and their associated compilers
• Configurable pretty print - enable or disable indentation, spaces before and after object member/array elements, and encoding.
• Supports reading/writing to/from strings, streams, and files.