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Pi Delport (talk | contribs) →Material deleted from "Carl Hewitt, the Actor model, and the birth of Scheme": please, give this a rest |
→Material deleted from "Carl Hewitt, the Actor model, and the birth of Scheme": It is important not to confuse the beginning of a controversy with how it ultimately turned out. |
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:::The inventors wanted to generalize the lambda calculus using serialized Actors.[[Special:Contributions/171.66.109.180|171.66.109.180]] ([[User talk:171.66.109.180|talk]]) 02:36, 3 November 2009 (UTC)
:::: Look, you're missing the point. '''''It does not matter at all''''' what Hewitt (or anyone else) thinks about first-class continuations versus actor message passing: this article is simply not concerned with their relative merits.
:::: If you think that the thrust of Sussman and Steele's work was that actors were just the lambda calculus in disguise, you must be grossly misreading or misunderstanding it. They were very explicit about Scheme not attempting to implement the full actor model, and carefully point out the exception of cells and serializers, as I pointed out above. They also clearly explain how ''"side effects, multiprocessing, and synchronization of processes'' [...]'' are very hard, if not impossible, to model using the substitution semantics of the lambda calculus, but'' [are] ''easily incorporated in other semantic models, including the environment interpreter and, perhaps more notably, the ACTORS model."''
::::: I cannot imagine how you could read this and conclude that they're implying actors and lambda calculus are the same. Please, give this a rest.
::: <span style="white-space:nowrap">—[[User:Piet Delport|Piet Delport]] <small>([[User talk:Piet Delport|talk]]) 2009-11-03 11:32</small></span>
It is important not to confuse the beginning of a controversy with how it ultimately turned out. The birth of Scheme was marked by two important controversies:
* '''The usefulness of Hairy Control Structure''' Even the revisionist history [http://www.brics.dk/~hosc/local/HOSC-11-4-pp399-404.pdf ''The First Report on Scheme Revisited'' Higher-Order and Symbolic Computation 1998] mentions that hairy control structure played an important role in the birth of Scheme. There is no doubt that contemporaneous publications document an important controversy about hairy control structure centered on the birth of Scheme.
*'''Whether Actors are just the lambda calculus in disguise''' People who were at MIT in 1975 report that there was even talk of Actors being a "fraud" because they were alleged to be just the lambda calculus in disguise. (Polities at MIT could be very fierce.) In later publications, it seems that Sussman and Steele backed off on this claim.
[[Special:Contributions/70.231.250.190|70.231.250.190]] ([[User talk:70.231.250.190|talk]]) 17:34, 3 November 2009 (UTC)
The quotation deleted from the article published in [http://arxiv.org/abs/0907.3330 ''ActorScript(TM): Industrial strength integration of local and nonlocal concurrency for Client-cloud Computing'' ArXiv 0907.3330 ] is as follows:
: [Sussman and Steele 1975] mistakenly concluded “we discovered that the 'Actors' and the lambda expressions were identical in implementation.” The actual situation is that the lambda calculus is capable of expressing some kinds of sequential and parallel control structures but, in general, not the concurrency expressed in the Actor model. On the other hand, the Actor model is capable of expressing everything in the lambda calculus and more.
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