~From Igor:
Since we started about compatibility, i have some things to report,
which i had to deal during porting.
deepCopy
- in Squeak , it behaves like a simple copy, which recursively
visiting references and sending to them #deepCopy. However, there is
no identity dictionary to check duplicated references, for this means
there is a
veryDeepCopy.
A veryDeepCopy in Squeak behaves similar to deepCopy in G/S. The
difference is, that there are some useful extensions, like
#veryDeepInner: and #veryDeepFixup: which can be overridden by
subclasses to customize deep copy behavior.
shallowCopy.
This is the last thing i had troubles with. In G/S it simply calls #copy.
In Squeak, there are expectation, that #shallowCopy is a low-level
copy message and you don't need to customize it, while #copy - can and
should be , if needed. And this was a source of problems: some classes
having a customized #copy , which shouldn't be called during
#shallowCopy.
I think, Squeak's #shallowCopy usage/implementation is more correct
than in G/S. I propose you to review its implementation.
There's another copy message - #clone, but we don't using it. The
difference between shallowCopy, that clone tries to inherit as much as
possible properties from original (read: identity hash).
Original issue reported on code.google.com by henrichs...@gmail.com on 24 Mar 2010 at 7:57
Original issue reported on code.google.com by
henrichs...@gmail.comon 24 Mar 2010 at 7:57