[hota_mazi]

Both Alan Kay and Joe Armstrong struck me as having had the same attitude of trying to capitalize on the topic of object oriented programming, failing to recognize its importance, and then later trying to appropriate it by redefining it.

Not the best moment of these otherwise two bright minds.

[skndr]

Didn’t Alan Kay coin the term “object oriented”?

[crdrost]

I don't believe he claims to, no.

He coined the term “object,” but what he meant by a computational object was different than what it came to mean: a data structure with associated operations upon it. Kay meant a parallel thread of execution which was generally sitting in a waiting state—one could make a very strong analogy between Smalltalk's vision of “objects” and what we call today “microservices,” albeit all living within the same programming language as an ecosystem rather than all being independent languages implementing some API.

But whether this is an “object-oriented” vision depends on whether you think that an object is intrinsically a data structure or an independent computer with its own memory speaking a common API. The most visible difference is that in the latter case one object mutating any other object's properties is evil—it is one computer secretly modifying another’s memory—whereas in the other case it is shrug-worthy. But arguably the bigger issue is philosophical.

That is hard to explain and so it might be best to have a specific example. So Smalltalk invents MVC and then you see endless reinventions that call themselves MVC in other languages. But most of these other adaptations of MVC have very object-oriented models: they describe some sort of data structure in some sort of data modeling language. But that is not the “object” understanding of a model in Smalltalk. When Smalltalk says “model” it means a computer which is maintaining two things: a current value of some data, and a list of subscribers to that value. Its API accepts requests to create/remove subscriptions, to modify the value, and to read the value. The modifications all send notifications to anyone who is subscribed to the value. There is not necessarily anything wrong with data-modeling the data, but it is not the central point of the model, which is the list of subscribers.

A more extreme example: no OOP system that I know of would do something as barbarous as to implement a function which would do the following:

> Search through memory for EVERY reference to that object, and replace it with a reference to this object.

That just sounds like the worst idea ever in OOP-land; my understanding of objects is as data structures which are probably holding some sort of meaningful data; how dare you steal my data structure and replace it with another. But Smalltalk has this; it is called Object.become. If you are thinking of objects as these microservicey things then yeah, of course I want to find out how some microservice is misbehaving and then build a microservice that doesn't misbehave that way and then eventually swap my new microservice in for the running one. (That also hints at the necessary architecture to do this without literally scanning memory: like a DNS lookup giving you the actual address, every reference to an object must be a double-star pointer under the hood.) And as a direct consequence, when you are running Smalltalk you can modify almost every single bit of functionality in any of the standard libraries to be whatever you need it to be, live, while the program is running. Indeed the attitude in Smalltalk is that you will not write it in some text editor, but in the living program itself: the program you are designing is running as you are writing it and you use this ability to swap out components to massage it into the program that you need it to become.

[alankay]

I didn't coin the term "object" -- and I shouldn't have used it in 1966 when I did coin the term "object-oriented programming" flippantly in response to the question "what are you working on?".

This is partly because the term at the time meant a patch of storage with multiple data fields -- like a punched card image in storage or a Sketchpad data-structure.

But my idea was about "things" that were like time-sharing processes, but for all entities. This was a simple idea that was catalyzed by seeing Sketchpad and Simula I in the same week in grad school.

The work we did at Parc after doing lots of software engineering to get everything to be "an object", was early, quite successful, and we called it "object-oriented programming".

I think this led to people in the 1980s wanting to be part of this in some way, and the term was applied in ways that weren't in my idea of "everything from software computers on a network intercommunicating by messages".

I don't think the term can be rescued at this point -- and I've quit using it to describe how we went about doing things.

It's worth trying to understand the difference between the idea, our pragmatic experiments on small machines at Xerox Parc, and what is called "OOP" today.

The simplest way to understand what we were driving at "way back then" was that we were trying to move from "programming" as it was thought of in the 60s -- where programs manipulated data structures -- to "growing systems" -- like Smalltalk and the Internet -- where the system would "stay alive" and help to move itself forward in time. (And so forth.)

The simplest way to think about this is that one way to characterize systems is that which is "made from intercommunicating dynamic modules". In order to make this work, one has to learn how to design and maintain systems ...

[crdrost]

Oh wow.

I was really not expecting you to join this conversation and I am very thankful to have crossed paths with you, even so briefly. Sorry for getting you wrong about the “objects” vs. “OOP” thing.

I have thought you could maybe call it “node-oriented” or “thread-oriented” but after reading this comment I think “ecosystem-oriented” might be more faithful a term?

[revvx]

Alan suggested "server-oriented programming" in Quora:

https://www.quora.com/What-is-Alan-Kays-definition-of-Object...

[davidrupp]

I think the inspiration from Simula I is something a lot of folks either don't know about, or maybe they know about it but don't recognize its significance. Objects with encapsulated state that respond to well-defined messages are a useful level of abstraction for writing simulations of the sort Simula was built for. They're just not automatically a particularly wieldy abstraction for systems that aren't specifically about simulation. Some (most?) of that is about the skill of the programmer, imo, not some inherent flaw in the abstraction itself.

P.S.: Thank you for all your contributions to our profession, and for your measured response to these kinds of discussions.

[alankay]

It's out of the context of this thread, but we were quite sure that "simulation-style" systems design would be a much more powerful and comprehensive way to create most things on a computer, and most especially for personal computers.

At Parc, I think we were able to make our point. Around 2014 or so we brought back to life the NoteTaker Smalltalk from 1978, and I used it to make my visual material for a tribute to Ted Nelson. See what you think. https://www.youtube.com/watch?v=AnrlSqtpOkw&t=135s

This system --including everything -- "OS", SDK, Media, GUI, Tools, and the content -- is about 10,000 lines of Smalltalk-78 code sitting on top of about 6K bytes of machine code (the latter was emulated to get the whole system going).

I think what happened is that the early styles of programming, especially "data structures, procedures, imperative munging, etc." were clung to, in part because this was what was taught, and the more design-intensive but also more compact styles developed at Parc seemed very foreign. So when C++, Java, etc. came along the old styles were retained, and classes were relegated to creating abstract data types with getters and setters that could be munged from the outside.

Note that this is also "simulation style programming" but simulating data structures is a very weak approach to design for power and scaling.

I think the idea that all entities could be protected processes (and protected in both directions) that could be used as communicating modules for building systems got both missed and rejected.

Of course, much more can and should be done today more than 40 years after Parc. Massive scaling of every kind of resource requires even stronger systems designs, especially with regard to how resources can be found and offered.

[hannofcart]

Are you the Alan Kay. Is there any way we can verify this is you? The HN user account seems to have a very low "karma" rating, so one can't help but be more suspicious.

[alankay]

I'm the "computing Alan Kay" from the ARPA/Parc research community (there's a clarinettist, a judge, a wrestler, etc.) I did create a new account for these replies (I used my old ARPA login name).

[hannofcart]

It's really cool that you weigh in on discussions on HN. Or I suppose it feels like that to me primarily because I grew up reading your quotes in info text boxes in programming texts. And it's cool to have that person responding to comments.

[filoeleven]

It’s a new account created yesterday. Alan Kay did an AMA here a while back+ with the username “alankay1” and occasionally posted elsewhere. That account’s last post was 7 months ago. Given that user “Alan-1”s style and content is similar, it seems likely that he created a new account after half a year away from HN.

If you want verification, maybe you can convince him to do another AMA =) I’m still thinking about his more cryptic answers from the last one, which is well worth a read. I think that was before Dynamicland existed, but I may be off.

+ https://news.ycombinator.com/item?id=11939851

[hota_mazi]

That's what he claims but there's zero evidence besides his own word.

[lliamander]

Well, how large is the pool of other possible candidates? Wouldn't someone from that time period (say the Simula folks, or another PARC employee) challenge that assertion? Why would he like?

[DonaldPShimoda]

Ah, so you have evidence that it was somebody else?

[hota_mazi]

I don't, but that's not how the burden of proof works.

[DonaldPShimoda]

Every source I've ever come across on this topic (and I work in PL research) points to Kay as the originator of the term "object-oriented" in relation to programming. No exceptions.

You are now making an affirmative assertion that Alan Kay did not coin the term. The burden of proof is on you, not him.

[hota_mazi]

Link these sources, then! Even someone who recently interviewed him and researched the subject for months confessed he could never corroborate that claim.

You make the claim he coined the term, the burden of proof is on you.

Until you do, it's perfectly reasonable and intellectually honest to reject that claim.

[IOT_Apprentice]

Alan Kay responded above so...

[DonaldPShimoda]

Link at [0].

I'm a little skeptical. That user certainly writes in a similar style to how I've seen Alan Kay write online, but I wouldn't be opposed to seeing some more proof. A one-day-old HN account claiming to belong to one of the most important people in CS from the past 50 years seems a little suspicious haha.

[0] https://news.ycombinator.com/item?id=19717640

[lliamander]

I'd be really interested to hear what you think they missed, because I find your claim to be surprising and a bit preposterous.

[hota_mazi]

Armstrong wrote the very famous "Why OO sucks" and then a decade or two later, changed his mind when he saw how successful OO was, and then tried to retrofit Erlang into an OO language. Not by changing Erlang, but by twisting the definition of OOP so that Erlang would fit it.

[alankay]

That isn't what happened at all (see the rebuttal by revvx). Joe was a great guy and also a great systems thinker. And he was the last person to worry about "bandwagons" (quite the opposite!)

[revvx]

I don't think that's what happened.

Joe Armstrong was criticizing C++-style OOP when he wrote his critique.

After he learned more about Alan Kay's view on OOP, he decided that Erlang is closer to Alan Kay's OOP and he approves that specific flavor of OOP.

He didn't change his stance based on popularity. He changed his stance because in the 80s/90s the term "OOP" was synonymous with C++-style-OOP, but that changed in the 2000s thanks to 1) C++-style OOP criticism became commonplace in our industry (thanks to people like Joe Armstrong) and 2) an increase of popularity languages like Ruby and Objective-C (which are closer to Smalltalk) and even much-maligned concepts such as DCOM, SOA and CORBA.

[hota_mazi]

He doesn't even mention C++ in his essay [1], but regardless, the C++ OOP is pretty much the mainstream OOP, which we still use today in Java, Kotlin, C#, etc...

And... no, the change in mindset about OOP never happened. Kay and Armstrong's view of OOP never took on. Today, OOP is still not seen as message passing and mostly seen as polymorphism, parametric typing, classes/traits/interfaces, and encapsulation. The complete opposite of what Erlang is.

[1] http://harmful.cat-v.org/software/OO_programming/why_oo_suck...

[revvx]

I'm the one mentioning C++. To anyone familiar with both styles, Joe Armstrong is clearly not talking about Smalltalk-style OOP in his essay, he's talking about C++/Java/etc style. And later on he only praised Smalltalk-style OOP.

And sorry, by a "change in mindset in our industry regarding OOP" I mean that it became commonplace to criticize C++-style OOP. Not that everyone stopped programming in that style. Maybe there's a better way to phrase it?

[alankay]

Again, please do your homework.

[tabtab]

"seen as" is the key here. "The masses" ultimately usually get to define terms, for good or bad. The gestalt or "feel" of what OOP "is" is often shaped by common languages and their common usage, again for good or bad.

It may be better to define specific flavors or aspects of OOP or OOP-ish things and discuss them in isolation with specific scenarios. That way the messy issue of canonical definition(s) doesn't come into play as often.

It would then be more of "hey, here's a cool feature of Language X or System X! Look what it can do...". Whether it's canonical or not is then moot.

[alankay]

This is way off. Please try to do more homework.