[Haskell-cafe] Where are rank-3 types necessary in practice for maintaining abstraction?

[Erik Hesselink]

The paper is here [1]. However, this is a sixth order function but not
rank-6 polymorphism (rank 6 type) IIUC.

Erik

[1] https://www.westpoint.edu/eecs/SiteAssets/SitePages/
Faculty%20Publication%20Documents/Okasaki/jfp98sixth.pdf

On 3 April 2018 at 17:10, Alex Rozenshteyn <rpglover64 at gmail.com> wrote:

> There's an easy to read paper by Okasaki titled "Even higher-order
> functions for parsing or Why would anyone ever want to use a sixth-order
> function?". Unfortunatly I can't find a link to a non-paywalled version. It
> shows how parser combinators themselves use rank-3 types and how defining a
> monad instance requires rank-6.
>
>
> On Tue, Apr 3, 2018 at 1:05 AM Joachim Durchholz <jo at durchholz.org> wrote:
>
>> Am 03.04.2018 um 08:54 schrieb Timotej Tomandl:
>> > Ok, I thought about it a bit more and realized mask in Control.Exception
>> > is the one where rank-3 is necessary, which is the example I was looking
>> > for.
>>
>> Given your newly acquired insights, do you expect that there will be
>> ultimately a valid example for higher ranks?
>> Is there a theoretical limit?
>> Or a practical one? E.g. it might be too awkward to mentally handle
>> higher-rank polymorphism - or maybe there's no real mental difference
>> when dealing with higher-ranked polymorphism, I don't know because I
>> didn't have to deal with that yet, so I'm curious.
>>
>>  > Sorry for the spam.
>>
>> Actually it was interesting.
>>
>> Regards,
>> Jo
>> _______________________________________________
>> 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.
>
>
> _______________________________________________
> 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.
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.haskell.org/pipermail/haskell-cafe/attachments/20180403/38ae9c71/attachment.html>