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Erik is a little trollish when expressing his opinions. From what I noticed, he loves flames. People either love his style or hate it. I guess you're in the later group - personally I don't mind when he's mocking something I care about, because from what I observed, he's always joking or half-joking and he'll say the opposite of what he just said in a couple of weeks.

> He is dismissive of "reactive programming" as nonsense from architecture astronauts, without giving a remotely fair description of what it actually is.

That's because his presentation is from React 2014, so he can fairly assume that the audience has some idea of what he's talking about, because "reactive" is the freaking topic of this audience - http://reactconf.com/

> if you're throwing punches you should know what you're talking about

Well, he kind of does. He's one of the architects of Reactive Extensions (Rx) and now he's contributing to RxJava. I don't agree with many of his opinions, for example I think they made design mistakes while architecting Rx, but he's OK in the knowledge department ;-)

> At 17:30 he makes a joke about a Steve Jobs function that says "iPhone", "iPad", "iCloud", and then "terminates naturally". Holy bad taste.

He also makes the same joke about himself - was trying to explain how streams are terminated, either naturally or by error (the joke on himself was that he was fired, i.e. onError).

> Well, he kind of does.

If he has that much background I would expect him to know better than to give such a poor example when he's trying to make fun of a definition as "dilbert-esque."

Tongue-in-cheek is a fun style and I totally get that, but if you're taking unfair hyperbolic pot-shots I think it should be at your own expense, not other people's. But that's just me.

> for example I think they made design mistakes

Curious to hear more.

Same here. For the record I think Rx is a lovely piece of work (as is LINQ btw). I can't think of anything I'd change in the bits of Rx that I've used so far.

One criticism is a lack of ability to express things like "back-pressure" where consumers indicate to producers to slow down, stop, etc..

That implies a two way dispatch which is not in the remit of reactive surely? A system that's closer to Haskell's pipes is probably what you'd want.

I think ISubject<I,O> has the interface for a pipe, with IObservable being a Producer equivalent, and IObserver being a Consumer equivalent. So there may be some cunning that could be done with your own implementations [to create an Effect]. (This is just wild brainstorming without looking at the code, so take all of this with a large pinch of salt).

Working within the Rx system, there'd be two ways of doing this:

The Observable has a mechanism for slowing down, but obviously it can't get instruction from observers - so it would have to make a judgment on what is 'too much'; a slow down would affect all observers. Definitely (well probably) not what you want.

The other way is to use the various buffering functions in Rx on the subscription, or roll your own function that has some intelligence. That localises the 'backing up' on a per observer basis, but doesn't slow down the observable itself.

To 'Stop' you could switch your subscription to Observable.Never<T> until you're ready to receive messages. Obviously you'll miss messages generated on the other stream whilst you were not listening.

Reactive = resilient + eventbased + responsive + scalable

I think it is relevant, what allows you to ignore the behavior of the system in favor of a component?

Dean wampler in a recent talk spoke of "Reactive Streams" which add this capability, but I have not seen it yet.

I have not seen anyone do this in Rx yet. Also ideally the back pressure is out of band to avoid starvation of that channel

I guess have an 'out of band' observable? Each observer that needs to communicate instruction back to the original observable can drop messages into an OoB observable, the original observable can subscribe to the OoB observable and then react to those messages as it sees fit.

Or do you think it should be an inherent feature of the stream itself? Isn't the point of IObservable to be the dual of IEnumerable, so calling Select on IEnumerable is a projection from A -> B, calling Select on IObservable is also a projection from A -> B, I think having an additional effect breaks that duality. So an Observable that has a side-channel or out-of-band stream wouldn't be an Observable, it'd be another category (which is why I suggested Pipes).

I totally understand why you'd want something like that, I'm just not sure it's fair to suggest Rx has design mistakes because of this though.

Well, speaking to the point of duality, I think Rx solves the problems it sets out to solve very nicely, and I would not say it has "design mistakes".

It certainly seems possible to use Rx primitives to build more functionality, yes.

Though everyone will have to build this themselves (if, of course, they even need it), and they'll probably all build it differently, where other lib's have this concept baked in (i.e. Pipes).

IMHO, libraries shouldn't try to do everything anyway, and to that end, Rx does it's thing and does it well (unix philosophy), as it's based on these mathematical abstractions.

When Erik mocks reactive programming I believe he is reacting to the Reactive Manifesto (http://www.reactivemanifesto.org/) currently being pushed by Typesafe and others.

My reading and feelings concerning the Manifesto mirror Erik's so I enjoyed listening to his mockery of it. I didn't really notice the MS bashing.

The issue with the Reactive Manifesto is that it is largely waffle. There are styles of programming that account for time, such as functional reactive programming. They tend to have formal definitions, or at least concrete implementations, so one can make objective statements about them. The Manifesto on the other hand is vague and full of platitudes. It's great for the Pointy-haired Boss, but there is little of substance than one can discuss in any objective manner.

[Update] I can understand how it's off-putting to listen to the presentation without this background.

Erik is one of the original signatories of that manifesto.

Erik Meijer is actually one of the main guys responsible for the popularization of 'reactive programming' with his Rx extensions for .NET [1]. It's probably a fair assumption that he knows more about this topic than most people.

[1] http://channel9.msdn.com/Shows/Going+Deep/Expert-to-Expert-B...

> if you're throwing punches you should know what you're talking about.

Ironically, I think you completely missed his point, probably because of an unfamiliarity with his background and history. He's not dismissive of reactive programming at all, quite the opposite! For example, he gave a course on Coursera about Functional Reactive Programming with Martin Odersky and Thomas Kuhn[0].

So my take on it is that he's just making fun of himself and his friends in a typical blunt Dutch fashion. Which of course doesn't work if you don't know the context.

[0] https://www.coursera.org/course/reactive

Cool, I'm totally open to the possibility that I missed the self-deprecating shtick from lack of context. If so, mea culpa.

When you say that he's mocking Microsoft engineers, is that because of the Visual Basic comments? Because Erik actually enjoys VB and was responsible for adding some features to it. He's a former employee, so there's context...

And I don't think he's being dismissive of reactive programming, he's dismissive of that definition, which is too broad. He was one of the main proponents of Reactive programming inside Microsoft.

> When you say that he's mocking Microsoft engineers, is that because of the Visual Basic comments?

"In Redmond, like a lot of people talk about code but don't write it, so I think Microsoft can only come back if, you know, they start writing more code."

> And I don't think he's being dismissive of reactive programming, he's dismissive of that definition, which is too broad.

The definition seems pretty reasonable to me. It immediately resonated with me; it described a principle I had been trying to achieve in some code I was writing recently. The idea of having changes automatically propagate through your model as a data-flow network is a pretty noticeable contrast to other ways of programming.

> He was one of the main proponents of Reactive programming inside Microsoft.

Yeah I guess I don't have this context. But without it, the talk just rubbed me wrong.

>"In Redmond, like a lot of people talk about code but don't write it, so I think Microsoft can only come back if, you know, they start writing more code."

It's like you've never worked at a tech shop with a sales team. Also keep in mind that it wasn't meant to be taken seriously or literally. If his audience wasn't terribly offended by it, why are you?

Erik was fired which is unbelievable; it's like firing Feynman. He obviously wasn't happy with Ballmer or the culture, and frankly neither were most of the MS employees in that audience. Ballmer's gone and suddenly everything MS does is becoming open sourced, for example. "A miracle". And just because quantum might sound cool, naming a razor blade after it doesn't make it quantum physics.

Correction - Erik wasn't fired.

> I'm all for rabble-rousing, but if you're throwing punches you should know what you're talking about.

http://en.wikipedia.org/wiki/Erik_Meijer_(computer_scientist...

pwnd ;-) Next time I'm back in Seattle to visit my ex-Microsoft SDE buddies we should grab a beer together.