These are chat archives for jdubray/sam

24th
Oct 2017
Janne Siera
@jannesiera
Oct 24 2017 14:03 UTC

@jdubray I tried reading your articles on STAR before, but didn't see you define it very precisely. Could you reference me to some place where you do, or otherwise provide a precise definition of STAR here?

Also, I would love to hear your definition of 'Action'. I read some of Leslie Lamport's papers and tbh haven't encountered a clear Action definition there either.

Janne Siera
@jannesiera
Oct 24 2017 14:18 UTC
Actually, this article seems to explain it slightly better to me (after reading the white papers) http://www.chorusjs.com/2015/06/13/sam-pattern/
Jean-Jacques Dubray
@jdubray
Oct 24 2017 14:48 UTC
STAR is purposely not defined with great precision, it's the equivalent of Light, Energy, Matter and Force in physics, depending on context you will emphasize one aspect or another, but at the end of the day, Matter, Light, Force and Energy cannot be mistaken, one for another. I am trying to get to the same level in Computer Science, can we broadly agree on a (small) set of concepts that make up the fabric of Software Engineering. This will greatly simplify evaluation and comparisons of new technologies . From there people can derive specific programming models, of which SAM is one of them.
So I really don't want to say much more than this:
image.png
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Dr. Lamport defines an action very clearly (primed values are property values of the next-state, i.e. the proposal)
Janne Siera
@jannesiera
Oct 24 2017 16:24 UTC

not defined with great precision, it's the equivalent of Light, Energy, Matter and Force in physics

This doesn't really hold up as those things are very precisely defined in Physics.

Thanks for the quote though. I hadn't seen it before. So his definition is: 'An action is a mathematical formula which contains both primed as unprimed variables.'