4 ms·

Almost no oop languages are actually oop according to Alan Kay. I think his OOP is closest to what we'd call actors today.

sfilargi 8y ago
Basically Erlang.
- Tomte 8y ago
  And Smalltalk, obviously. Did Simula fit that description fully? I've never seen a Simula program in my life.
  - gridlockd 8y ago
    Simula was retroactively given the label "object-oriented", but the more appropriate term (according to Smalltalkers) for it would be "class-oriented" like its descendants C++/Java.
stcredzero 8y ago
Smalltalk Inheritance was regarded as a mistake by the Smalltalk intelligentsia in the early 2000's. Message passing and polymorphism was where it was at. Functional programming was discussed by them back then. My own area of interest right now involves Actors with pluggable lambdas.
jcelerier 8y ago
Alan Kay said in some OOPSLA address that microservices were OOP.
- staticassertion 8y ago
  I actually wanted to post the same thing. Alan Kay's view of OOP is mostly just the actor model. But the actor model, like OOP, does not tell us how to actually build programs. "When do I use an object?" is a question OOP does not answer, "When do I use an actor?" is similarly not answered by the actor model. Service Oriented Architecture is also effectively the actor model, but with a focus on the persistent process abstraction. What Microservices does is take the actor model and say: * Here's how you figure out where the actor abstractions should go, how large they should be, and patterns for interaction Where microservices soooort of diverges is in its lack of discouragement of synchronous communication. But if you build your microservices using queues, I think you get the right sized actors with all of those benefits, without going down a rabbit hole of trying to structure every single bit of logic as an actor. AWS's "Cell Based Architecture" is also just actors, but with its own set of patterns for how large to build them.
userbinator 8y ago
Fortunately it does not matter, because the industry seems to have mostly gotten out of the "if it's not X-oriented it's bad" dogmatic mindset that spurred the "OOP craze" of the 90s and early 2000s.
- majewsky 8y ago
  If it's not JSON-oriented, it's bad. If it doesn't use machine learning, it's bad. If it doesn't use blockchain, it's bad.
- BigJono 8y ago
  I dunno about that. Try being a JS dev that likes mutability and dislikes static typing.
pdkl95 8y ago
Ruby gets close (which is one of the reasons I use it a lot): * Function calls are messages sent to objects, which can be sent to any object directly with Object#send and received as messages when an object[1] responds to #message_missing. * Local state is stored in objects as @foo variables. Ruby is a multi-paradigm language, so it's not strict about enforcing the privacy of local state, but that's rarely a big deal. Ruby softly encourages using an OOP message-passing style with e.g. Module.attr_accessor defining simple accessor wrappers instead of reading local state directly. * The extreme lateness and mutability of binding in Ruby is (in)famous for making ruby slow and hard to optimize. [1] I don't mean "defined in the class"; changes can be specific to a particular object instance. obj = Object.new obj.define_singleton_method(:method_missing) do |method,*args| puts method.to_s.capitalize end obj.hello! # prints "Hello!"
4lch3m1st 8y ago
From his talk on OOPSLA[1], I'd say that only Smalltalk and Common Lisp (through CLOS) were able to perform OO as Kay envisioned. Erlang is another story: it would probably be better to call it just actor model. But again, Kay himself says[2] that there is not a lot of difference between actor model and his OOP. [1] https://www.youtube.com/watch?v=oKg1hTOQXoY https://www.youtube.com/watch?v=oKg1hTOQXoY [2] https://www.quora.com/What-is-the-difference-between-Alan-Kays-definition-of-OOP-and-Carl-Hewitts-Actor-Model https://www.quora.com/What-is-the-difference-between-Alan-Ka...
- madhadron 8y ago
  Add Self to your list, which was even purer than Smalltalk since it got rid of the classes and let the objects stand by themselves. It's not just the actor model, though. In the actor model, all the actors are contributors to the conversation. The subjects of conversation are something else. In object oriented programming, the subjects of conversation are the same category of things as the agents of conversation, and may move back and forth freely. The simplest way to see the difference is to think about how a new contributor to the conversation is added. In the actor model, some actor forks a new actor in response to a message. If I have built up the state to describe a new actor, there is still a step to bring it to life that changes it from one thing to another. In object oriented programming, when you build up that state, it may become a contributor to the conversation at any point in time and then go back to being a subject of conversation, or do both at once. There is no switch.

sfilargi 8y ago

Basically Erlang.

Tomte 8y ago
And Smalltalk, obviously. Did Simula fit that description fully? I've never seen a Simula program in my life.
- gridlockd 8y ago
  Simula was retroactively given the label "object-oriented", but the more appropriate term (according to Smalltalkers) for it would be "class-oriented" like its descendants C++/Java.

stcredzero 8y ago

Smalltalk Inheritance was regarded as a mistake by the Smalltalk intelligentsia in the early 2000's. Message passing and polymorphism was where it was at. Functional programming was discussed by them back then. My own area of interest right now involves Actors with pluggable lambdas.

jcelerier 8y ago

Alan Kay said in some OOPSLA address that microservices were OOP.

staticassertion 8y ago
I actually wanted to post the same thing. Alan Kay's view of OOP is mostly just the actor model. But the actor model, like OOP, does not tell us how to actually build programs. "When do I use an object?" is a question OOP does not answer, "When do I use an actor?" is similarly not answered by the actor model. Service Oriented Architecture is also effectively the actor model, but with a focus on the persistent process abstraction. What Microservices does is take the actor model and say: * Here's how you figure out where the actor abstractions should go, how large they should be, and patterns for interaction Where microservices soooort of diverges is in its lack of discouragement of synchronous communication. But if you build your microservices using queues, I think you get the right sized actors with all of those benefits, without going down a rabbit hole of trying to structure every single bit of logic as an actor. AWS's "Cell Based Architecture" is also just actors, but with its own set of patterns for how large to build them.

userbinator 8y ago

Fortunately it does not matter, because the industry seems to have mostly gotten out of the "if it's not X-oriented it's bad" dogmatic mindset that spurred the "OOP craze" of the 90s and early 2000s.

majewsky 8y ago
If it's not JSON-oriented, it's bad. If it doesn't use machine learning, it's bad. If it doesn't use blockchain, it's bad.
BigJono 8y ago
I dunno about that. Try being a JS dev that likes mutability and dislikes static typing.

pdkl95 8y ago

Ruby gets close (which is one of the reasons I use it a lot): * Function calls are messages sent to objects, which can be sent to any object directly with Object#send and received as messages when an object[1] responds to #message_missing. * Local state is stored in objects as @foo variables. Ruby is a multi-paradigm language, so it's not strict about enforcing the privacy of local state, but that's rarely a big deal. Ruby softly encourages using an OOP message-passing style with e.g. Module.attr_accessor defining simple accessor wrappers instead of reading local state directly. * The extreme lateness and mutability of binding in Ruby is (in)famous for making ruby slow and hard to optimize. [1] I don't mean "defined in the class"; changes can be specific to a particular object instance. obj = Object.new obj.define_singleton_method(:method_missing) do |method,*args| puts method.to_s.capitalize end obj.hello! # prints "Hello!"

4lch3m1st 8y ago

From his talk on OOPSLA[1], I'd say that only Smalltalk and Common Lisp (through CLOS) were able to perform OO as Kay envisioned. Erlang is another story: it would probably be better to call it just actor model. But again, Kay himself says[2] that there is not a lot of difference between actor model and his OOP. [1] https://www.youtube.com/watch?v=oKg1hTOQXoY https://www.youtube.com/watch?v=oKg1hTOQXoY [2] https://www.quora.com/What-is-the-difference-between-Alan-Kays-definition-of-OOP-and-Carl-Hewitts-Actor-Model https://www.quora.com/What-is-the-difference-between-Alan-Ka...

madhadron 8y ago
Add Self to your list, which was even purer than Smalltalk since it got rid of the classes and let the objects stand by themselves. It's not just the actor model, though. In the actor model, all the actors are contributors to the conversation. The subjects of conversation are something else. In object oriented programming, the subjects of conversation are the same category of things as the agents of conversation, and may move back and forth freely. The simplest way to see the difference is to think about how a new contributor to the conversation is added. In the actor model, some actor forks a new actor in response to a message. If I have built up the state to describe a new actor, there is still a step to bring it to life that changes it from one thing to another. In object oriented programming, when you build up that state, it may become a contributor to the conversation at any point in time and then go back to being a subject of conversation, or do both at once. There is no switch.