[Squeak-e] Programming the VM

Mark S. Miller markm at caplet.com
Mon Feb 3 01:36:10 CET 2003

At 12:21 AM 2/3/2003 Monday, cg at cdegroot.com wrote:
>Is this looking at Islands, basically, but then nested? Again the $1000
>dollar question arises: by what scope? It seems here that you are
>talking about machines, therefore about execution environment, therefore
>about some form of dynamic scopery. 

Let's say object A is instantiated on "machine" X and object B is 
instantiated on "machine" Y. Let's say X and Y allow A to call B. The act of 
A calling executes on X under X's rules, observation, and control. The 
behavior of B being called (executing the called method) likewise executes 
on Y. The virtualization/hosting/ownership environment is according to the 
object's creation context, not its calling context. 

This is lexical scoping, not dynamic scoping, just as Alan's metaphor would 
seem to demand. Object references stretch between "machines". Messages move 
between "machines" riding references. Objects stay where they're born.

Text by me above is hereby placed in the public domain


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