[Haskell-cafe] Coercible between data A a b = A a b and (a, b)

[Artem Pelenitsyn]

Hello Oleg,

Is there a good, somewhat up-to-date source of reference to find out what
exactly is different? Is it the STG paper from 1992 (“Implementing lazy
functional languages on stock hardware”)?

--
Best wishes,
Artem Pelenitstyn

On Mon, 25 Feb 2019 at 10:17 Oleg Grenrus <oleg.grenrus at iki.fi> wrote:

> Two data types are `Coercible` (as in Data.Coerce) if their representation
> in memory is the same: they are representiationally equivalent You ask for
> looser structural isomorphism, consider e.g.
>
>     data B b = B {-# UNPACK #-} !Int b
>
> and
>
>     (Int, b)
>
> The values of these types have quite different representation/memory
> layout.
>
> - Oleg
>
> On 25 Feb 2019, at 16.38, Georgi Lyubenov <godzbanebane at gmail.com> wrote:
>
> Greetings!
>
> Is there any reason behind/what is the reason behind
> ```
> data A a b = A a b
> ```
> and
> ```
> (a, b)
> ```
>
> not being coercible?
>
> And in general all n-ary constructors not being coercible to one another?
>
> Thanks in advance!
>
> =======
> Georgi
>
> _______________________________________________
> 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/20190307/13f6285c/attachment.html>