Re: [boost] GSoC 2014 - Functional - Monad

Subject: Re: [boost] GSoC 2014 - Functional - Monad
From: Ding Xiangfei (a0113627_at_[hidden])
Date: 2014-03-26 21:45:40

Ding Xiangfei <a0113627 <at> nus.edu.sg> writes:

> 
> Vicente J. Botet Escriba <vicente.botet <at> wanadoo.fr> writes:
> 
> > 
> > Le 17/03/14 08:46, Ding Xiangfei a écrit :
> > > Hello, Vincete,
> > >
> > >    Thank you for the previous advice. Based on the ideas I had, I have 
> written a draft proposal for this
> > project. The Google Doc link is as follow:
> > >
> > >          https://docs.google.com/document/d/1sdgO63-
> SFo9IhPvfcwNSrwVEey9Pl9V9ftmZDPzrqO4/edit?usp=sharing
> > >
> > >    As the proposal is not final and I am still thinking about any new 
> ideas about monads, I would like to invite
> > you for comments and evaluation on
> > > the manageability and viability of this project.
> > >
> > >    Besides, I also added some experimental features that I would like 
to 
> make during (hopfully) or after this
> > summer. Comments on these features are
> > > also appreciated.
> > >
> > >
> > Hi,
> > 
> > there is something I find incoherent on the prose. Fisrt you say "the 
> > conception of monads allows functional programming languages to perform 
> > a sequence of instructions just as imperative languages. Last you say 
> > that "monads will simplify function chaining and exception handling when 
> > the code is written in a functional fashion".
> > 
> > C++ is a multi-paradigm language that supports already the imperative 
> > style and a clean exception handling machinery. How monads can help C++?
> > Why it would be worth to write programms in C++ in a functional monadic 
> > style? To be able to perform a sequence of instructions? C++ has already 
> > all that.
> > Why monads style will be useful in C++?
> > 
> > How do you plan to "simplify type resolution and compile time"?
> > 
> > Could you tell more about  "dynamic typing of monads"?
> > 
> > Could you elaborate on the operations the monads you plan to provide 
> > will support?
> > In addition to monad operations do you plan to provide other? e.g. what 
> > list operations? Waat do you mean by asynchronous function chaining? 
> > Error-handling?
> > 
> > Could you show an example of user code making use of monads interface?
> > 
> > Could you show an example of developer code making a type behave as a 
> monad?
> > 
> > Do you plan to use CRTP? Do you plan to use dynamic polymorphism?
> > 
> > What kind of performance would you evaluate? And to which alternative 
> > would you compare? Do you have already an idea of the bechmarks 1 and 2?
> > 
> > Having a concept without associated algorithms is not too useful. Do you 
> > have examples of algorithms that build on top of the monads interface?
> > 
> > Do you think that you will be able to finish with a Boost ready for 
> > review library at the end of the program?
> > 
> > Globally your proposal could be improved a lot by adding more detail.
> > 
> > HTH,
> > Vicente
> > 
> > _______________________________________________
> > Unsubscribe & other changes: 
> http://lists.boost.org/mailman/listinfo.cgi/boost
> 
> Hello Vicente,
> 
>   Thank you very much for your valuable advice. As I am amending the 
> proposal I will give some examples of the interface and algorithms running 
> on it.
>   In order to make the project more manageable, I decided not to go too 
> ambitious and trimmed out the part on 'dynamic typing' (because I think 
that 
> it is trivial at this moment) and trying to increase type-resolution 
> efficiency to make sure things just work nicely before the end of summer.
> 
> Regards,
> Ding Xiangfei
> 
> _______________________________________________
> Unsubscribe & other changes: 
http://lists.boost.org/mailman/listinfo.cgi/boost

Hello Vicente,
    I have replied the comment on the proposal. Just in case, I will explain 
wwhat I have done recently here.

    I have make the part of the implementation working for the bitonic 
sorter example. Here is the link to the source code: 
https://gist.github.com/dingxiangfei2009/4970b62159cd1dca1868.

    I was not aware of the wait_for_all issue, so that one was re-
implemented for illustrative purpose. Besides, then() method was not 
implemented, so a rudimentary implementation was used to replace that 
method.

    I also read the documentation on boost::optional and wrote a skeleton 
for optional monad. I was not clear whether there was a proposal for 
expected class, but I indeed found an implementation written by ptal on 
github. I took it as a reference.

    I hope that you can give some feedback on this sample code, what are the 
improvements to be made and what I have overlooked, etc.

    Thank you very much. Have a nice day.

Regards,
Ding Xiangfei