[Q] Backward compatible code

Lic. Edgar J. De Cleene edgardec2001 at yahoo.com.ar
Wed Dec 1 13:58:28 UTC 2004


Fellows Squeakers:

I trying to build a Help system for Squeak, and I saving "cards" as
compressed objects (and saving that to somewhere for later use).

Works as long how images are compatibles.

Backwards compatibility is a long talked issue in Computers, so I wish to
know how could be a Smalltalk / Squeak smart solution .

In Squeak3.8gamma-6475.image I have

AbstractString

This class provides the abstract super class for the original String (that
represents an array of 8-bit Characters) and MultiString (that represents an
array of  32-bit MultiCharacters).  In the similar manner of LargeInteger
and SmallInteger, those subclasses are chosen accordingly for a string;
namely as long as the system can figure out so, the String is used to
represent the given string.

But older images don't know and you get a PopUp with guessing.

Some clues ? Could one object know what Squeak versions was originated ?

Edgar




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