On Mar 29, 2011, at 9:58 PM, Denis Kudriashov wrote:
> Hello
>
> I have many morphs saved in files by smartReferenceStream. I doing it in
> pharo1.1 image.
> Now I want to load this objects to pharo1.2.
> When I doing this I have exception about absent TextConstants stuff. My saved
> Morph containes textMorph.
> I know pharo1.2 has textMorph refactored and TextConstants was removed.
>
> How old object can be migrated to new stuff? Is some rules exists?
No, I don't think so... keeping the system compatibel at that level is *really*
difficult... simple refactoring can be done
(e.g. etoys did that for years), but complex changes in the image will be
nearly impossible if you require serializability compatibility
at that level. (especially when using image segment style low-level
serialization).
Being compatible on that level was religion for Squeak (and it's even today). I
personally don't think that what we have is
valuable enough to define compatibility on that level to be more impotant than
being able to evolve the system.
The system as it is now is just not good enough to have any form of future with
it, so trading "improve it" vs. "be backward compatible
on a binary level" is selection between having the past and having a future...
Marcus
--
Marcus Denker -- http://www.marcusdenker.de
INRIA Lille -- Nord Europe. Team RMoD.
