Converting JavaScript to Ruby with RKelly
I've been working on a yet-to-be-released project called RKelly, which will parse JavaScript and return a parse tree suitable for passing to Ruby2Ruby. Ruby2Ruby will then give you back ruby code that you can eval.
I thought I would share a few examples of what I have working so far, and also write a bit about where I want to go.
I have most simple looping working. For example, a for loop:
require 'ruby2ruby'
rkelly = RKelly.new
puts RubyToRuby.new().process(rkelly.process(DATA.read))
__END__
for(var i = 0; i < 10; i++) {
alert('hello world');
}
Will produce:
i = 0
while (i < 10) do
alert("hello world")
[i, i = (i + 1)].first
end
end
You can even calculate the Fibonacci sequence:
require 'ruby2ruby'
rkelly = RKelly.new
puts RubyToRuby.new().process(rkelly.process(DATA.read))
__END__
function fib(n) {
var s = 0;
if(n == 0) return(s);
if(n == 1) {
s += 1;
return(s);
} else {
return(fib(n - 1) + fib(n - 2));
}
}
Which produces:
s = 0
return s if (n == 0)
if (n == 1) then
s = (s + 1)
return s
else
return (fib((n - 1)) + fib((n - 2)))
end
end
Why am I torturing myself like this? I want to add JavaScript support to Mechanize, and I think I can do that with RKelly. So far I have been able to use RKelly for simple DOM manipulation with a slightly modified copy of Mechanize. If you would like to see that in action, just find me at one of the Seattle Ruby Brigade meetings.
I've also added some simple object support, which you can see after the jump.
Here is an example of simple object support:
require 'ruby2ruby'
class OpenStruct
def alert(s)
puts s
end
end
rkelly = RKelly.new
puts RubyToRuby.new().process(rkelly.process(DATA.read))
__END__
function foo() {
alert('I am awesome!');
}
function bar() {
this.blah = foo;
}
var baz = new bar;
baz.blah();
Which will produce the following code:
def initialize
super()
bar()
end
def bar
class << self
def blah()
alert("I am awesome!")
end
end
end
end
def foo
alert("I am awesome!")
end
def bar
class << self
def blah()
alert("I am awesome!")
end
end
end
baz = Bar.new
baz.blah()
Posted by Aaron Patterson • Permalink • Leave your Comment »
Eric Hodel says:
No rkelly.to_ruby?
Monday, 16 April 2007 @ 2:45pm
Aaron Patterson says:
Not yet. I’ll add that!
Monday, 16 April 2007 @ 4:18pm
jax says:
Oh my God! I was just bra shopping and thinking how I needed simple object support, but opted to manipulate a slightly modified copy of a former bra. Baby got back rub-y. Genius.
Wednesday, 18 April 2007 @ 6:56pm
topfunky says:
I once saw a comic that described a horrific future where we would program servers in Javascript.
I would be careful, Aaron, because I’m sure some Terminator will be sent from the future to stop this from becoming a reality.
Thursday, 19 April 2007 @ 3:39pm