Duktape for U++

This repository contains a set of C++ template bindings, which allow you to use Duktape in your U++ applications.

Duktape is a lightweight embeddable Javascript engine, with a focus on portability and compact footprint.

Support for U++ specifics like String and Value types is provided, as well as a set of templates for generating bindings.

Everything you see here is an early work in progress, and the API is subject to change. Feedback and help of any kind is also very much appreciated - I'm sure the templates can be improved alot.

Examples

See the examples and autotest directories for examples of how to use the bindings.

The autotest directory contains a set of U++ autotest style testcases.

Package

The Duktape package has the following dependencies:

• Core
• libduktape

The Duktape package is set to link the libduktape library by default, assuming a system wide installation. At present, it has only been tested on MSYS2 Clang64. Likely, the flags will need to be adjusted for other platforms and/or custom Duktape builds.

Features

• Support for basic types
• Basic support for String and Value types
• Binding global functions
• Binding global values (not variables)
• Binding struct/class types
• Binding constructor
• Binding methods

Missing features

• Binding C++ variables
• Inheritance
• Overloading
• Lots more :)

Binding details

Functions bindings generate a wrapper Duktype C function, and store the original function pointer in a field DUK_HIDDEN_SYMBOL("funcptr") of the wrapper.

Class bindings generate a prototype object which is stored in the heap stash. For example for a class C, the prototype object is stored in the heap stash under the key:

String key;
key << DUK_HIDDEN_SYMBOL("__class__");
key << typeid(C).name()

The this pointer is stored in the object under DUK_HIDDEN_SYMBOL("thisptr").

Class methods are stored in a hidden field their corresponding C function, under DUK_HIDDEN_SYMBOL("methodobj"). The value is the method pointer itself, saved in a Duktype lstring.

The bindings provide a simple print function, which can be used to print to the console. It can be registered using the function DuktapeRegisterPrint. By default the output stream is Cout(). This can be changed by calling DukPrintSetStream. The stream bound to print can be returned with DukOut().

print take a variable number of arguments, and will print them separated by a space. The arguments are converted to strings using duk_safe_to_string.