Introduction

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ChaiScript is one of the only embedded scripting language designed from the ground up to directly target C++ and take advantage of modern C++ development techniques, working with the developer like he expects it to work. Being a native C++ application, it has some advantages over existing embedded scripting languages:

It uses a header-only approach, which makes it easy to integrate with existing projects.
It maintains type safety between your C++ application and the user scripts.
It supports a variety of C++ techniques including callbacks, overloaded functions, class methods, and stl containers.

Requirements

ChaiScript requires a C++11 compiler to build with support for variadic templates. It has been tested with gcc 4.6 and clang 3.1 (with libcxx). MacOS 10.8 (Mountain Lion) is also known to support the C++11 build with Apple's clang 4.0. MSVC 2013 or newer is supports also. For more information see the build dashboard.

Usage

Add the ChaiScript include directory to your project's header search path
Add #include <chaiscript/chaiscript.hpp> to your source file
Instantiate the ChaiScript engine in your application. For example, create a new engine with the name chai like so: chaiscript::ChaiScript chai
The default behavior is to load the ChaiScript standard library from a loadable module. A second option is to compile the library into your code, see below for an example.

Once instantiated, the engine is ready to start running ChaiScript source. You have two main options for processing ChaiScript source: a line at a time using chai.eval(string) and a file at a time using chai.eval_file(fname)

To make functions in your C++ code visible to scripts, they must be registered with the scripting engine. To do so, call add:

chai.add(chaiscript::fun(&my_function), "my_function_name");

Once registered the function will be visible to scripts as "my_function_name"

Examples

ChaiScript is similar to ECMAScript (aka JavaScript(tm)), but with some modifications to make it easier to use. For usage examples see the "samples" directory, and for more in-depth look at the language, the unit tests in the "unittests" directory cover the most ground.

For examples of how to register parts of your C++ application, see "example.cpp" in the "src" directory. Example.cpp is verbose and shows every possible way of working with the library. For further documentation generate the doxygen documentation in the build folder or see the website http://www.chaiscript.com.

The shortest complete example possible follows:

/// main.cpp

#include <chaiscript/chaiscript.hpp>

double function(int i, double j)
{
  return i * j;
}

int main()
{
  chaiscript::ChaiScript chai;
  chai.add(chaiscript::fun(&function), "function");

  double d = chai.eval<double>("function(3, 4.75);");
}

Or, if you want to compile the std lib into your code, which reduces runtime requirements.

/// main.cpp

#include <chaiscript/chaiscript.hpp>
#include <chaiscript/chaiscript_stdlib.hpp>

double function(int i, double j)
{
  return i * j;
}

int main()
{
  chaiscript::ChaiScript chai(chaiscript::Std_Lib::library());
  chai.add(chaiscript::fun(&function), "function");

  double d = chai.eval<double>("function(3, 4.75);");
}