Notice

Please refer to the official project: github.com/sebastien/k7. The information presented here may not be the most accurate and is not the most up-to-date.

K7 - A standard library for V8

Author: Sebastien Pierre sebastien@type-z.org
Date: 28-Sep-2008
Updated: Sat Aug 8 13:03:24 EDT 2009 -- Joshaven

Project Description

The K7 projects aims at creating a high-quality standard library for Google's open source V8 JavaScript Engine.

The main goal of K7 is to facilitate server-side JavaScript through providing a standard library that simplifies the use and extension of V8.

K7 Extension: Modules & Macros

K7 facilitates JavaScript interpreter extension through encouraging Modules (standardized building blocks) that are plugged into K7 and loaded on demand by K7. The creation of modules is simplified through the use of Macros (single instructions that expand into a set of instructions). The process of working with the V8 JavaScript Engine is simplified through K7 Macros.

Macros

K7 simplifies the creation of extensions through simple macros that aid in tying your into modules into the V8 JavaScript Engine.

Modules

The K7 module system is organized in a module tree consisting of API documentation, C and/or JavaScript files which are loaded upon demand. The module tree structure is presented in doc/API.yaml but built by convention through crawling the lib/ directory structure.

Please keep these principals in mind when writing extensions:

• Keep It Short and Simple -- Avoid writing complex extension modules with lots of functions and classes. "Everything should be made as simple as possible, but no simpler" - Albert Einstein
• Stick to Standards -- Provide binding to standard, well-known API (like POSIX). This allows to keep the extensions simple, make maintenance and usage easier.
• Use JavaScript for JavaScript objects -- Write JavaScript objects in pure JavaScript. For example, a module providing a 'File' object should construct the file object in pure JavaScript. In this example, the JavaScript should in turn, take advantage of the 'posix' C module for the actual I/O.
• Choose Dependencies Carefully -- When you want to start writing an extension, pick a library that follows the UNIX philosophy "do one thing and do it well." A good example of a clean & functional library is 'libcurl'.

Composition

The k7 source code is separated in two primary folders:

• src/ which contains the K7 infrastructure source code.
• lib/ which contains the extension modules. The directory defines the module hierarchy. For instance, The source code for the 'system.posix' extension module is located in 'lib/system/posix/'.

Getting Started

Prerequisites

POSIX (Unix/Linux/Mac) environment, gcc, git, python scons & subversion

Obtaining Source

Create a ~/src directory and check out k7 out into it ~/src/k7

mkdir -p ~/src
cd ~/src
git clone git://github.com/sebastien/k7.git
cd k7

Compiling (A.K.A. Installation)

Building and downloading dependencies, namely the V8 source, is as simple as typing make as root.

sudo make
sudo make install

You may also wish to take advantage of other make options: You have a couple of options that you can activate:

make compact # Builds a compressed K7 executable
make DEBUG=1 # Enables debugging mode
make STATIC=1 # Embeds K7 modules within the executable
make LIBTASK=1 # Embeds libtask and provides a 'yield' feature

Usage

To confirm your installation you can type which k7 which should yield "/usr/local/bin/k7" or "/usr/bin/k7" depending upon where you installed k7.

To execute a JavaScript file simply type k7 followed by a reference to the script, for example:

k7 examples/intro-helloworld.js