Hello World From V8

2009-11-13 00:00:00 +0000 by Alex R. Young

Heard of V8 but haven't got a clue how to run it? Here's a quick guide
to get you started. This guide is intended for Mac OS, but there are
detailed Windows instructions.

V8 is actually a C++ JavaScript engine, designed to be embedded in
another program. Fortunately Google provide a sample shell that can be
built with the bundled build chain.

Step 1: Get Scons

Assuming you've already got Xcode installed, get
Scons. V8 uses this as its build tool. It's easy to install from source, but you could also use MacPorts. MacPorts
will fetch a whole bunch of dependencies -- if you're on Leopard or Snow
Leopard you should be OK to just build it yourself.

I installed it like this:

sudo python setup.py install

Step 2: Build V8

Fetch V8 from the Google Code subversion repository:

svn checkout http://v8.googlecode.com/svn/trunk/ v8

Then build V8 and the sample shell:

# Wait for a bit...
scons sample=shell

You will be able to run the interpreter with ./shell.

Step 3: A Less Painful Interpreter

To get command history and more, install rlwrap. I actually
did install this from ports.

Then run: rlwrap ./shell.

Step 4: Hello World

V8 version
> print("hello world");
hello world

I also tried a library I wrote, with insanely fast results: