Re: [Jython-dev] Jython and native java merged with simplicity

[Samuele P. <pe...@in...>]

...

> 
> 
> For demonstration purposes I'm embedding the feature
> in directly into the PyInstance.  I define a new
> private method called setSkeleton in PyInstance.java.
Make sense for demo, but for the long run is a no-go.

> 
> 
> I add a bit of code in __setattr__ and __findattr__
> which will search the skeleton instance first before
> self.  When setting the attribute I check to see if it
> is a "basis type" (i.e. float int string).  If it is
> not I must check that object to see if it has a
> skeleton.  If so, set the ghost attribute with the
> ob's skeleton.
> 
> 
> I include an extra optional argument to init args
> called __skeleton__.  If it's None I do nothing, if it
> is defined, I set the PyInstance's skeleton class
> before we assign attributes to the instance.  This way
> the skeleton will automatically be initialized since
> __setattr__ and __findattr__ have been slightly
> modified.  
> 
> 
> What is important about the nature of ghosting is that
> information is stored in both the java native skeleton
> and the real PyObject.
Why this two-places approach? once you have a skeleton
you can store things there, unless an attribute
is not a pre-existent java field.

> 
> This seems funny, and alot of work, but really isn't. 
> Once you see the speed boost obtained from doing bulk
> processing you may deem this feature worthwhile.
OK, but you stil pay reflection for calling java methods,
so you get a real speedup maybe only if your java methods
are coarse-grain.

> 
> 
> It does retain a great deal of python flexibility.  
> Provided a small set of attributes are not deleted. 
> That should throw an exception.
> 
> 
> thanks for your comments. have been very helpful.
> -john
You're welcome. 
For the momement I see this as an interesting experiment,
but to have such a functionality be distributed with jython
I think we need the 2.2 framework, in order to make
this a flavor of java subclassing under the control of a special-purpose
meta-class.
At least I hope that these words will make sense at that point.

regards, Samuele Pedroni.