Generating Code with for Loops

let's say we have the following code:

```
for x in a
    ...code...
end
```

This should become the following code in JavaScript

``` javascript
for( x = a.next(); x != EOI; x = a.next()){
    ...code...
}
```

Note that the iterable should have a next method and some kind of way to return an EOI (end of iterable) so that writing the javascript is easy.
