Colin Putney wrote:
> The other aspect to SystemEditor is that it's more flexible than 
> ClassBuilder about migrating instances. It currently has one migration 
> strategy - the standard one that maps values according to ivar names and 
> assigns nil to any new ivars. But other migrators can be used as well. I 
> plan to take advantage of this in Monticello2 with a migrator that can 
> handle class and ivar renames, and of course custom migrators can be 
> built as well. The only thing missing to allow this is a protocol for 
> specifying the migrator to use for a given class.

Remember that migrating instances is really done by the class itself via 
#updateInstancesFrom: and probably shouldn't be hardcoded in either 
ClassBuilder or SystemEditor.

Cheers,
   - Andreas