On Wednesday 10 May 2017 08:35 PM, H. Hirzel wrote:
> Hi Subbu
>
> Squeak 2.4 had a WorldMorph class as a subclass of PasteUpMorph.
> But Squeak 2.4 had no WorldState class..
>
> In Squeak 2.5 a WorldState class was introduced and the WorldMorph
> class was removed.

http://wiki.squeak.org/squeak/715 (WorldMorph) seem to hint that it was 
done to support nested worlds (as in projects), but has no explanation.

http://wiki.squeak.org/squeak/1818 (WorldState) states that it was 
created to implement world functions for pasteups which respond true to 
isWorldMorph.

Both entries are silent on the rationale behind the change. What are the 
pros and cons of WorldState vs WorldMorph approaches? Is the close ties 
to hardware elements (screen, HID events, ..) a major factor?

Regards .. Subbu