[PD] Abstraction [define]

[Mathieu Bouchard]

On Sun, 17 Dec 2006, Frank Barknecht wrote:
> Mathieu Bouchard hat gesagt: // Mathieu Bouchard wrote:
>> I'd say, a state is whatever you may want to save. Is that a good
>> definition?
> This would be my basic definition as well. Even this has some direct
> consequences: What I want to save is different from what you want to
> save.

Maybe we could came up with some kind of classification of state and 
state-like members of objects... something like:

1. state that doesn't have any impact on anything except efficiency of the 
program. this means caches/memoizers, prefetch buffers, precalculations, 
etc.

2. state that doesn't have any impact on anything if you run the program 
without a GUI.

3. other state.

A. state that gets already saved automatically in .pd files
B. state that doesn't.

So that makes 6 categories: 1A 1B 2A 2B 3A 3B. The category of something 
can depend on which level you look it at. Things that happen inside an 
abstraction or other class, can mean something at one level and then 
disappear (be invisible) from outside.

> So the next questions are: How to tell Pd what should be saved and what 
> not? Or: Can Pd make educated guesses about what should and shouldn't be 
> saved? Should Pd guess at all?

Pd can't guess whether any state is category 1: that's a meaning created 
by the contract of the class. A "contract" is a set of guarantees about 
input, and a set of guarantees about output, for which the deal is that as 
long as input are correct, outputs ought to be correct. There's no way to 
encode such meanings in pd as it is now (except as comments).

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| Mathieu Bouchard - tél:+1.514.383.3801 - http://artengine.ca/matju
| Freelance Digital Arts Engineer, Montréal QC Canada