[Pyobjc-dev] pickled Objective-C objects

[Ronald O. <ous...@ci...>]

I noticed the other day that our unicode subclass doesn't support 
pickling. Should we add support for pickling, and if so how? Should 
instances of our subclass be pickled just like 'normal' unicode objects 
(although I have no idea how to do that), or as NSString values?

Normal Objective-C classes also don't support pickling, should we add a 
reduce method to the proxy that calculates the object state using 
NSCoder (where possible)? It might also be possible to provide a 
default implementation of initWithCoder: and encodeWithEncoder: if the 
parent class implements those.

The default encodeWithEncoder: implementation would call the superclass 
implementatation, then a NSDictionary containing the Objective-C 
instance variables and python __slots__ and then an NSDictionary 
containing the python __dict__.

The __reduce__ method would use the result of [self encodeWithEncoder:] 
as the object state, and the restore function would use that state to 
restore the object using initWithCoder:.

Does this look like a valid approach? If it is I'll probably file a bug 
report containing this scheme (I don't think I'll get around to 
implementing this anytime soon).

Ronald