[Haskell-cafe] exceptions, errors, random

[Dennis Raddle]

Looking at my application needs, such as access to pseudorandom numbers and
threads, does this suggest a particular course of action?

D


On Tue, Jun 20, 2017 at 1:40 AM, Ivan Lazar Miljenovic <
ivan.miljenovic at gmail.com> wrote:

> There are two general schools of thought as to how to deal with exceptions:
>
> * ExceptT/MonadError from transformers/mtl:
> http://www.mega-nerd.com/erikd/Blog/CodeHacking/
> Haskell/what_do_you_mean.html
>
> * The exceptions package (which is a lifted variant of
> Control.Exception in base):
> https://www.fpcomplete.com/blog/2016/11/exceptions-best-practices-haskell
>
> On 20 June 2017 at 15:53, Dennis Raddle <dennis.raddle at gmail.com> wrote:
> > Just want to bump this request as I have not gotten a reply.
> >
> > On Fri, Jun 16, 2017 at 1:45 PM, Dennis Raddle <dennis.raddle at gmail.com>
> > wrote:
> >>
> >> I am wondering what exception/error and random classes I should use for
> my
> >> application.
> >>
> >> The application will be doing Monte Carlo backtracking search. I want it
> >> to be multithreaded and run on all four cores on my MacBook.
> >>
> >> I need detailed error messages in order to investigate errors. So I will
> >> throw errors or exceptions, then catch them in lower functions and
> annotate
> >> them with the parameters or computations within the lower function, then
> >> re-throw until finally the exception pops into the terminal.
> >>
> >> Because it's multi-threaded, at least some parts will needs to be in IO.
> >> Also, because it's a Monte Carlo algorithm it will need to make
> pseudorandom
> >> choices.
> >>
> >> Perhaps I should put everything in the IO monad? This will give me
> access
> >> to threads and the standard generator seed. But how about throwing,
> >> catching/rethrowing exceptions in IO? I have done this in pure code
> before:
> >> not sure if it's better to do it that way, in which case I could put
> some
> >> kind of state monad to hold the random seed together with an error
> monad and
> >> IO at the core of the monad stack.
> >>
> >> Any advice welcome.
> >> D
> >>
> >
> >
> > _______________________________________________
> > Haskell-Cafe mailing list
> > To (un)subscribe, modify options or view archives go to:
> > http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe
> > Only members subscribed via the mailman list are allowed to post.
>
>
>
> --
> Ivan Lazar Miljenovic
> Ivan.Miljenovic at gmail.com
> http://IvanMiljenovic.wordpress.com
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.haskell.org/pipermail/haskell-cafe/attachments/20170620/308ff869/attachment.html>