cl-spidermonkey provides a Javascript runtime environment inside of Common Lisp by embedding a widely-used and tested Javascript engine: Mozilla's SpiderMonkey.

With full access to Javascript from Common Lisp, it becomes easier to test Javascript libraries in the same breath as normal testing. It also allows a Lisp REPL to be used as a Javascript REPL, and for many other combinations of lisp and JS.

Before you do anything you need the git repostiory.

git clone git://github.com/gonzojive/cl-spidermonkey.git

First you need to compile Spidermonkey. It's not that bad! Just cd into the vendor directory and then run the install script:

cd vendor
sh install-spidermonkey.sh

That will download and install SpiderMonkey, and set up all the paths properly.

Now you should be able to load the library in lisp:

REPL> (asdf:operate 'asdf:load-op :cl-spidermonkey)

To make sure everything's peachy, run the test suite:

REPL> (asdf:operate 'asdf:load-op :cl-spidermonkey-tests)
REPL> (spidermonkey-tests:spidermonkey-tests)

Right now there are only two exported symbols, so things are pretty easy:

REPL> (sm::with-js-context (context)
       (sm:evaluate-js "10 * 24;"))
240

Note that you can only get doubles, ints, strings, voids (undefined), nulls, and boolean values back from EVALUATE-JS. Any other object will come back as a pointer to a JS_Object whichs needs further attention from the bindings. If you are so inclined, lookat the src/spidermonkey-bindings.lisp file for more info on how to deal with native Spidermonkey objects.