[Haskell-cafe] Best Actor system?

Fri Mar 28 11:39:32 UTC 2014

As mentioned before, there is Cloud Haskell:
http://www.haskell.org/haskellwiki/Cloud_Haskell

On 27 March 2014 23:22, Patrick Wheeler <patrick.john.wheeler at gmail.com>wrote:

> @tom - forkIO and freineds works great for lightweight local threads, what
> about non-local threads though in a distributed setting.  Is there anything
> in haskell that you think replaces that functionality in erlang?
>
>
> On Thu, Mar 27, 2014 at 10:34 PM, <amindfv at gmail.com> wrote:
>
>> Unfortunately I can't help with recommending an actor library. I think
>> peoples' responses of "you should never want to do that" are, um, unhelpful.
>>
>> That said, i've written both haskell and erlang professionally, and never
>> had a need for actors/message passing in haskell. It may be the wrong tool
>> for most haskell jobs.
>>
>> The main things erlang-style concurrency gets you are
>>  - lightweight threads (in haskell by default -- 'forkIO' creates
>> lightweight threads)
>>  - limited shared mutable state (haskell's pure)
>>  - spreading computation over cores (in haskell you want parallelism not
>> concurrency -- check out the Par monad)
>>  - computation over boxes (see distributed-process)
>>
>> To do "message passing", check out MVars (and later, STM)
>>
>> Tom
>>
>>
>> El Mar 27, 2014, a las 17:40, james <james at mansionfamily.plus.com>
>> escribió:
>>
>>  On 27/03/2014 17:28, Christopher Allen wrote:
>>
>>  I don't actually want to get drawn into this, but one point would be
>> that it's really just the same fallacies as OOP in general, but concurrent.
>>
>>
>> Well, horses for courses, I've been writing distributed C++ apps since
>> cfront was shiny and new.
>>
>> I find writing off OOP as distasteful as writing off functional, and
>> there are people in both camps.
>>
>> I have ordered Simon's book and will take care to read it.
>>
>> In the mean time - does anyone have an answer to the question I asked?
>>
>> James
>>
>>  The idea that isolation behind an interface (message passing or not) is
>> going to prevent unnecessary mutation or side effects from getting out of
>> control.
>>
>>  In practice, it doesn't do that at all and the fact that you're making
>> your inter-dependencies more implicit, rather than explicit, through the
>> use of isolated buckets of side-effecting state and mutation is going to
>> make it harder rather than easier to debug the program when it invariably
>> breaks. I'd rather get a call-stack if I'm going to abandon Haskell-y
>> goodness. And your Actors *will* get into a bad state, so you'll end up
>> writing Inspector and Debugger mixins just to keep a handle on the
>> complexity when they get into that bad state.
>>
>>  It's not impossible for Actors to make sense. I used agents (which are
>> not full-blown Actors per se) in Clojure for side-effect isolation,
>> serialization, and thread safety to good effect, but I kept how much "work"
>> they did to a bare minimum and tried to keep everything in pure functions
>> as long as I could.
>>
>>  It's just that I see programmers with a shiny new hammer looking for
>> every nail they can find.
>>
>>
>>
>> On Thu, Mar 27, 2014 at 12:21 PM, Zongheng Yang <zongheng.y at gmail.com>wrote:
>>
>>> Can anyone give some detailed cons of Akka / actor model?
>>>
>>> On Thu, Mar 27, 2014 at 5:21 AM, Alois Cochard <alois.cochard at gmail.com>
>>> wrote:
>>> > I have good experience with actors (Scala/Akka), and I can tell you
>>> that you
>>> > should avoid them as much as possible.
>>> > I think the model is good if you need to do some low level concurrency
>>> > coding on a language that don't have effect tracking in types.
>>> >
>>> > Having used the Async library from Marlow, I highly recommend it...
>>> and it
>>> > probably cover a big percentage of traditional concurrency use cases.
>>> >
>>> > You still have Haskell Cloud if you want distributed messaging.
>>> >
>>> > Cheers
>>> >
>>> >
>>> >
>>> > On 27 March 2014 06:29, james <james at mansionfamily.plus.com> wrote:
>>> >>
>>> >> Having been introduced to actors by looking at Erlang, I discovered
>>> Akka.
>>> >>
>>> >> It seems that the performance is pretty impressive and I like the
>>> model.
>>> >>
>>> >> There seem to be several basic Actor libraries in Hackage, but they
>>> don't
>>> >> seem
>>> >> to be very actively developed.
>>> >>
>>> >> I'm more interested in the model for programming within a single
>>> runtime
>>> >> than I am for distributed systems, but message and dispatch
>>> performance
>>> >> definitely is important.
>>> >>
>>> >> Can anyone share experiences with the different packages?  Is any one
>>> >> of them stand-out?
>>> >>
>>> >> Thanks
>>> >> James
>>> >>
>>> >>
>>> >> _______________________________________________
>>> >> Haskell-Cafe mailing list
>>> >> Haskell-Cafe at haskell.org
>>> >> http://www.haskell.org/mailman/listinfo/haskell-cafe
>>> >
>>> >
>>> >
>>> >
>>> > --
>>> > Alois Cochard
>>> > http://aloiscochard.blogspot.com
>>> > http://twitter.com/aloiscochard
>>> > http://github.com/aloiscochard
>>> >
>>> > _______________________________________________
>>> > Haskell-Cafe mailing list
>>> > Haskell-Cafe at haskell.org
>>> > http://www.haskell.org/mailman/listinfo/haskell-cafe
>>> >
>>> _______________________________________________
>>> Haskell-Cafe mailing list
>>> Haskell-Cafe at haskell.org
>>> http://www.haskell.org/mailman/listinfo/haskell-cafe
>>>
>>
>>
>> _______________________________________________
>> Haskell-Cafe mailing list
>> Haskell-Cafe at haskell.org
>> http://www.haskell.org/mailman/listinfo/haskell-cafe
>>
>>
>> _______________________________________________
>> Haskell-Cafe mailing list
>> Haskell-Cafe at haskell.org
>> http://www.haskell.org/mailman/listinfo/haskell-cafe
>>
>>
>
>
> --
> Patrick Wheeler
> Patrick.John.Wheeler at gmail.com
> Patrick.J.Wheeler at rice.edu
> Patrick.Wheeler at colorado.edu
>
> _______________________________________________
> Haskell-Cafe mailing list
> Haskell-Cafe at haskell.org
> http://www.haskell.org/mailman/listinfo/haskell-cafe
>
>

-- 
*Alois Cochard*
http://aloiscochard.blogspot.com
http://twitter.com/aloiscochard
http://github.com/aloiscochard
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.haskell.org/pipermail/haskell-cafe/attachments/20140328/1e63b4fa/attachment.html>