rantings and ravings
Joaquim Baptista [pxQuim]
px%fct.unl.pt at Forsythe.stanford.edu
Wed Apr 17 12:28:00 UTC 1991
The shadowing technique that you refer may make sense in a database world,
1) Safety requirements mean that organizations like banks MUST keep
every "version" of an account, for instance.
2) Objects don't change that much (my account doesn't, for instance).
In a dynamic language such as Self or Smalltalk, measurements indicate
a LARGE number of VERY SHORT LIVED objects, such as activation records.
Do you really want to keep a copy of all the invocations of the
method "Integer +"?
So, you should at least separate "interesting" objects from "temporary"
objects. The problem is, it may not be easy to distinguish them
automatically. So, you probably end up telling the compiler what
objects should be considered "interesting". But if you do so, the
proposal resembles persistency, and is not so new anymore.
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