C#'s IObservable<>/IObserver<> made me think how would a dual [1][2] of a range concept look in D. Since D has no equivalent IEnumerable<> (as it is no needed thanks to templates) it is only about IEnumerator<> / IObserver<> part which relates to a D range.

Ranges/enumerators are models of 'pull' style interface whereas their duals represent models of 'push' style enabling reactive programming [3] techniques which are really nicely solving issues of asynchronous / event - based programming.

I suppose OutptRange is similar in concept, although it has 'OnCompleted' / 'OnError' missing.

What do you think? Rx along with LINQ is a really clean solution to the problem of asynchronous ranges of values. I think it would be very nice to have in D too.

[1] http://csl.stanford.edu/~christos/pldi2010.fit/meijer.duality.pdf
[2] http://josemigueltorres.net/index.php/ienumerableiobservable-duality/
[3] https://channel9.msdn.com/Shows/Going+Deep/Expert-to-Expert-Brian-Beckman-and-Erik-Meijer-Inside-the-NET-Reactive-Framework-Rx

On Thursday, 27 February 2014 at 12:41:14 UTC, Szymon Gatner wrote:
> C#'s IObservable<>/IObserver<> made me think how would a dual

Topic should of course be: "Duals OF ranges and reactive D"

On 02/27/2014 01:41 PM, Szymon Gatner wrote:
> C#'s IObservable<>/IObserver<> made me think how would a dual [1][2] of
> a range concept look in D. Since D has no equivalent IEnumerable<> (as
> it is no needed thanks to templates) it is only about IEnumerator<> /
> IObserver<> part which relates to a D range.
>
> Ranges/enumerators are models of 'pull' style interface whereas their
> duals represent models of 'push' style enabling reactive programming [3]
> techniques which are really nicely solving issues of asynchronous /
> event - based programming.
>
> I suppose OutptRange is similar in concept, although it has
> 'OnCompleted' / 'OnError' missing.
>
> What do you think? Rx along with LINQ is a really clean solution to the
> problem of asynchronous ranges of values. I think it would be very nice
> to have in D too.
>
> [1] http://csl.stanford.edu/~christos/pldi2010.fit/meijer.duality.pdf
> [2] http://josemigueltorres.net/index.php/ienumerableiobservable-duality/
> [3]
> https://channel9.msdn.com/Shows/Going+Deep/Expert-to-Expert-Brian-Beckman-and-Erik-Meijer-Inside-the-NET-Reactive-Framework-Rx
>

In case you are interested, I have thrown together a small proof of concept implementation: http://dpaste.dzfl.pl/9d8386768da0

On Saturday, 8 March 2014 at 12:01:10 UTC, Timon Gehr wrote:
> On 02/27/2014 01:41 PM, Szymon Gatner wrote:
>> C#'s IObservable<>/IObserver<> made me think how would a dual [1][2] of
>> a range concept look in D. Since D has no equivalent IEnumerable<> (as
>> it is no needed thanks to templates) it is only about IEnumerator<> /
>> IObserver<> part which relates to a D range.
>>
>> Ranges/enumerators are models of 'pull' style interface whereas their
>> duals represent models of 'push' style enabling reactive programming [3]
>> techniques which are really nicely solving issues of asynchronous /
>> event - based programming.
>>
>> I suppose OutptRange is similar in concept, although it has
>> 'OnCompleted' / 'OnError' missing.
>>
>> What do you think? Rx along with LINQ is a really clean solution to the
>> problem of asynchronous ranges of values. I think it would be very nice
>> to have in D too.
>>
>> [1] http://csl.stanford.edu/~christos/pldi2010.fit/meijer.duality.pdf
>> [2] http://josemigueltorres.net/index.php/ienumerableiobservable-duality/
>> [3]
>> https://channel9.msdn.com/Shows/Going+Deep/Expert-to-Expert-Brian-Beckman-and-Erik-Meijer-Inside-the-NET-Reactive-Framework-Rx
>>
>
> In case you are interested, I have thrown together a small proof of concept implementation: http://dpaste.dzfl.pl/9d8386768da0

Wow, that is now what I'd small ;) I will definitely take a look.

Is it something you already had written or something new? How do you feel about the concept?

On 03/10/2014 08:26 PM, Szymon Gatner wrote:
>>
>> In case you are interested, I have thrown together a small proof of
>> concept implementation: http://dpaste.dzfl.pl/9d8386768da0
>
> Wow, that is now what I'd small ;) I will definitely take a look.
>
> Is it something you already had written or something new?

I've written it in response to you post. (Note that it works with DMD 2.064.)

> How do you feel about the concept?

It does not make a lot of sense with value semantics, so efficiency might be a concern. I don't know how useful this specific implementation (that deviates from std.range only slightly) would be in practice (e.g. probably one wants to be able to reserve space even if writing is not random access.)

On 2/27/14, 4:41 AM, Szymon Gatner wrote:
> C#'s IObservable<>/IObserver<> made me think how would a dual [1][2] of
> a range concept look in D. Since D has no equivalent IEnumerable<> (as
> it is no needed thanks to templates) it is only about IEnumerator<> /
> IObserver<> part which relates to a D range.
>
> Ranges/enumerators are models of 'pull' style interface whereas their
> duals represent models of 'push' style enabling reactive programming [3]
> techniques which are really nicely solving issues of asynchronous /
> event - based programming.
>
> I suppose OutptRange is similar in concept, although it has
> 'OnCompleted' / 'OnError' missing.
>
> What do you think? Rx along with LINQ is a really clean solution to the
> problem of asynchronous ranges of values. I think it would be very nice
> to have in D too.
>
> [1] http://csl.stanford.edu/~christos/pldi2010.fit/meijer.duality.pdf
> [2] http://josemigueltorres.net/index.php/ienumerableiobservable-duality/
> [3]
> https://channel9.msdn.com/Shows/Going+Deep/Expert-to-Expert-Brian-Beckman-and-Erik-Meijer-Inside-the-NET-Reactive-Framework-Rx

Continuing an old thread. Seems like the Observable interface pioneered by RX would be of interest and good use to D, since observables are the dual of ranges and ranges are so useful to us.

Erik Meijer sent me a bunch of informative links about Rx, pasted below. I've perused a few and gained an understanding of Rx, and will grab him for some more chat later.

I think this is a great project to look into, but currently can't dedicate much time to it. I encourage anyone who feels passionate about this to grab the torch. Thanks!

* Netflix use case  server:
http://techblog.netflix.com/2013/01/optimizing-netflix-api.html, client: http://channel9.msdn.com/posts/YOW-2012-Jafar-Husain-Rx-and-Netflix-A-Match-Made-in-Composable-Asynchrony.

* RxJava: https://github.com/Netflix/RxJava/wiki, have a look at the docs https://github.com/Netflix/RxJava/wiki/Transforming-Observables#groupby-and-groupbyuntil.

* Increasingly people are providing RX bindings such as
http://slid.es/petermd/eclipsecon2014, http://camel.apache.org/rx.html.

* The Soundcloud folks started using RxJava on Android,
http://mttkay.github.io/blog/2013/08/25/functional-reactive-programming-on-android-with-rxjava/, and now that is catching like wildfire.
http://markhudnall.com/2013/10/15/rxjava-and-android/.

* GitHub is also all in on Rx, they wrote an ObjectiveC port
https://github.com/ReactiveCocoa/ReactiveCocoa.

* Early implementation for PHP https://github.com/asm89/Rx.PHP

* RxJs: https://github.com/Reactive-Extensions/RxJS. There are bindings
for several frameworks https://github.com/Reactive-Extensions/RxJS#what-about-my-libraries.

* Internal course for Netflix front-end engineers https://github.com/jhusain/learnrx.

* www.introtorx.com a free book written by a guy who has been using Rx to make real $$$$ writing high frequency trading algos in London.

* The new lift-based implementation makes it relatively straightforward to port an Rx implementation to another language; the main engineering effort wrt to pert is how to best handle thread safety. In RxJava we tried to do as much lock-free styles as possible, but the downside is crazy complex CAS state machines, and in many cases you cannot beat the JVM JIT when it comes to using regular locks & synchronized methods.


Andrei

Reactive programming is related to dataflow, so you will run into problems when you get beyond toy-size programs. Though, with compiler support…

http://cs.brown.edu/~sk/Publications/Papers/Published/bck-lowering-opt-trans-frp/paper.pdf

On Thursday, 8 May 2014 at 19:52:01 UTC, Ola Fosheim Grøstad wrote:
> Reactive programming is related to dataflow, so you will run into problems when you get beyond toy-size programs. Though, with compiler support…
>
> http://cs.brown.edu/~sk/Publications/Papers/Published/bck-lowering-opt-trans-frp/paper.pdf

Any update on introducing Observable push concepts into D?