Re: [Pyobjc-dev] Headache over hacking an XML editor

[Just v. R. <ju...@le...>]

bb...@ma... wrote:

> Thread starts here:
> 
>      http://sourceforge.net/mailarchive/message.php?msg_id=2347617
> 
> But this particular response [of mine] contains the most detailed
> explanation on why I don't believe it is possible to eliminate
> retain/release/autorelease entirely from the Python side of the
> bridge:
> 
>      http://sourceforge.net/mailarchive/message.php?msg_id=2349810
> 
> And another thread that may also be illuminating:
> 
>      http://sourceforge.net/mailarchive/message.php?msg_id=2342178
> 
> And another thread:
> 
>      http://sourceforge.net/mailarchive/message.php?msg_id=2331515

Ugh, this is depressing :-(. (So you _can_ find out the return type of a
method at runtime but not whether it returns a new or a borrowed
reference. Great.)

Here's a quick idea to work around the most common (I think) irritation:
instead of raising an exception when calling a (subclass of) NSObject
("TypeError: Use class methods to instantiate new Objective-C objects")
have objc-object.m::object_new() do this:

        self = cls.alloc()
        self.release()  # ownership transferred to the Python wrapper
        return self

This doesn't touch the alloc() semantics, yet provides a much more
Pythonic way to create instances. Heck, this will even call __init__()
for you! ;-)

What I still don't understand is how pyobjc manages the refcount of
Python objects passed to objc: the Python object can't have a reference
to it, so when will the wrapper be released? Is it an autorelease
object?

Just