What is it?
-----------
This is a small module that runs Javascript code on Google's V8 engine.
The module takes any valid Javascript string, compiles it, runs and returns the result of
of the command as a (Python) string. When appropriate, boolean or float objects are
also returned. Think of this as eval() in Python. This is released under the BSD license.
Prerequisites
-------------
To build this, you will need to build v8, of course. You will also need to install Cython. I am
sure this can also run on Pyrex, but I have not formally tried it yet.
Building it
-----------
$ python setup.py build_ext --inplace
# add libv8 to your library path
$ export LD_LIBRARY_PATH=/path/to/libv8
This should build v8onpython.so and let you import the module.
Usage
-----
After building it, import it.
>>> import v8onpython
>>> v = v8onpython.Script()
>>> js_code = "for (i=0;i<1000000;i++){\n j=i+1\n}"
>>> v.compile(js_code)
1000000.0
>>> v.compile('1 < 2')
True
>>> v.compile("'Hello' + ', World!'")
'Hello, World!'
>>> v.compile("1.32w")
'SyntaxError: Unexpected token ILLEGAL'
>>> v.compile('a')
'ReferenceError: a is not defined'
Experimental Javascript console
-------------------------------
As of revision 25, there is a custom JS console/interpreter. It has
history, colors, command search via Ctrl+R, and tab completion.
It will get better over time:
$ python repl.py
[v8onpython Javascript console. Press Ctrl+D to exit]
v8onpy > var x=234
v8onpy > x[TAB]
x x.toExponential x.toFixed
x.toLocaleString x.toPrecision x.toString
v8onpy > x.toString()
234
v8onpy > Array.[TAB]
Array.constructor Array.isPrototypeOf Array.propertyIsEnumerable Array.toString
Array.hasOwnProperty Array.length Array.toLocaleString Array.valueOf
v8onpy > function add(a,b){return a+b}
v8onpy > add(9,'2')
92
v8onpy >
That's all! If you have any feedback, please send me an email at dfdeshom at gmail com
What would be cool
------------------
* Code contributions
* Performance numbers of CPython vs JS on V8.
* expand this and make Python and JS talk faster using
objects, callbacks, etc
