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Hewitt created actors after hearing an early Smalltalk talk by Kay at MIT, as I recall it. That wasn't the only influence (capabilities were a big one, for inst

Hewitt created actors after hearing an early Smalltalk talk by Kay at MIT, as I recall it. That wasn't the only influence (capabilities were a big one, for instance) and I'd be surprised if there wasn't reciprocal influence, though. In Hewitt's actor model, messages are also (immutable) actors. At least in the early version I read about.

ProfHewitt 7y ago
Actors were developed to unify and overcome limitations of previous important contributions including lambda calculus [Church 1932] (first-class procedures), Petri nets [Petri 1962] (true concurrency), semaphores [Dijkstra 1962-1963], packet switching [Baran 1964] (concurrent communication between computers using fixed size packets), capabilities [Dennis and van Horn 1966] (pointer security), Simula [Dahl and Nygaard 1967] (class hierarchy), and SmallTalk-72 [Goldberg and Kay 1976] (bit-mapped computer graphics and browser, the precursor of modern programming Integrated Development Environments). The lambda calculus could not express concurrency with the consequence that lambda calculus programs can be thousands of times slower than Actors. A Petri net cannot dynamically expand and has the limitation that tokens can miraculously disappear from different places, which is inefficient to implement. Capabilities have the limitation that pointers must be manipulated using indexes into capability lists thereby making programming awkward. Simula did not implement concurrency and did not have messages. SmallTalk-72 used a byte stream of program tokens thereby making it awkward for concurrency. See the following for more information: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3418003 https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3418003
- agumonkey 7y ago
  another cyclical influence is scheme trying to reimplement the actor model in a lisp/lambda clothing.
  - ProfHewitt 7y ago
    The programming language Scheme was originally named Schemer against Actors ;-) The monad (https://wiki.haskell.org/Monad https://wiki.haskell.org/Monad) is another mostly unsuccessful lambda calculus way to try to address some of the issues resolved in the Actor Model.
    - agumonkey 7y ago
      My english is failing me, what's the meaning behind 'schemers against actors' ? I only knew about actors for its scheme influence and the fact that it was highly concurrent (even this I'm not so sure). I got into college way too late for it to be studied sadly.
      - ProfHewitt 7y ago
        The original name of the programming language Scheme was "Schemer", which was shortened by removing the last character because of file system limitations. The motivation for the name Schemer was that the authors were scheming against Actors analogous to the programming Conniver, where the authors were conniving against Planner.
        agumonkey 7y ago
        Oh I see the trail goes deep. Interesting.
    - deleted 7y ago
      [deleted]

ProfHewitt 7y ago

Actors were developed to unify and overcome limitations of previous important contributions including lambda calculus [Church 1932] (first-class procedures), Petri nets [Petri 1962] (true concurrency), semaphores [Dijkstra 1962-1963], packet switching [Baran 1964] (concurrent communication between computers using fixed size packets), capabilities [Dennis and van Horn 1966] (pointer security), Simula [Dahl and Nygaard 1967] (class hierarchy), and SmallTalk-72 [Goldberg and Kay 1976] (bit-mapped computer graphics and browser, the precursor of modern programming Integrated Development Environments). The lambda calculus could not express concurrency with the consequence that lambda calculus programs can be thousands of times slower than Actors. A Petri net cannot dynamically expand and has the limitation that tokens can miraculously disappear from different places, which is inefficient to implement. Capabilities have the limitation that pointers must be manipulated using indexes into capability lists thereby making programming awkward. Simula did not implement concurrency and did not have messages. SmallTalk-72 used a byte stream of program tokens thereby making it awkward for concurrency. See the following for more information: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3418003 https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3418003

agumonkey 7y ago
another cyclical influence is scheme trying to reimplement the actor model in a lisp/lambda clothing.
- ProfHewitt 7y ago
  The programming language Scheme was originally named Schemer against Actors ;-) The monad (https://wiki.haskell.org/Monad https://wiki.haskell.org/Monad) is another mostly unsuccessful lambda calculus way to try to address some of the issues resolved in the Actor Model.
  - agumonkey 7y ago
    My english is failing me, what's the meaning behind 'schemers against actors' ? I only knew about actors for its scheme influence and the fact that it was highly concurrent (even this I'm not so sure). I got into college way too late for it to be studied sadly.
    - ProfHewitt 7y ago
      The original name of the programming language Scheme was "Schemer", which was shortened by removing the last character because of file system limitations. The motivation for the name Schemer was that the authors were scheming against Actors analogous to the programming Conniver, where the authors were conniving against Planner.
      - agumonkey 7y ago
        Oh I see the trail goes deep. Interesting.
  - deleted 7y ago
    [deleted]