[core libraries] Adding Backwards to base, re-export from Control.Applicative

[Edward Kmett]

I’m a strong +1 on moving Backwards and Reverse to base. This is basically free for everybody for a nice consistency win.

I’m -1 on exporting them from Control.Applicative. That module is imported unqualified by a significant cross section of the Haskell ecosystem, so this just gratuitously introduces risk of name conflicts for little tangible benefit. In the presence of possible conflicts there I’d err on the side of the status quo over change for change’s sake.

The only real precedent for doing so is that Control.Applicative also gratuitously exports Const, which is more historical accident than precedent to follow.

-Edward

> On Nov 27, 2019, at 1:36 PM, chessai . <chessai1996 at gmail.com> wrote:
> 
> 
> I think that makes sense. It wouldn't be disruptive, both changes are small but useful.
> 
>> On Wed, Nov 27, 2019, 3:08 PM David Feuer <david.feuer at gmail.com> wrote:
>> If Backwards moves, then Reverse probably should too.
>> 
>>> On Mon, Nov 25, 2019, 6:58 PM Baldur Blöndal <baldurpet at gmail.com> wrote:
>>> I'll CC Haskell Libraries
>>> 
>>> þri., 12. nóv. 2019 kl. 22:14 skrifaði Ryan Scott <ryan.gl.scott at gmail.com>:
>>>> This discussion definitely belongs on the mailing list, yes.
>>>> 
>>>> Ryan
>>>> 
>>>>> On Tue, Nov 12, 2019 at 11:59 AM chessai . <chessai1996 at gmail.com> wrote:
>>>>> I support this. +1
>>>>> 
>>>>> Should we copy in the libraries mailing list?
>>>>> 
>>>>>> On Tue, Nov 12, 2019, 5:56 AM Baldur Blöndal <baldurpet at gmail.com> wrote:
>>>>>> Is it time to move Control.Applicative.Backwards module from transformers to base, and maybe re-export it from Control.Applicative.
>>>>>> 
>>>>>> It's an interesting, important, simple property of Applicative that they can be run backwards.
>>>>>> -- 
>>>>>> You received this message because you are subscribed to the Google Groups "haskell-core-libraries" group.
>>>>>> To unsubscribe from this group and stop receiving emails from it, send an email to haskell-core-libraries+unsubscribe at googlegroups.com.
>>>>>> To view this discussion on the web visit https://groups.google.com/d/msgid/haskell-core-libraries/CAK9DwL9vPwA%3DJ%3DoZ%3D%2BKrM_k6TcZ89dvzvo0%2B288yDR8HL4bsDw%40mail.gmail.com.
>>>>> 
>>>>> -- 
>>>>> You received this message because you are subscribed to the Google Groups "haskell-core-libraries" group.
>>>>> To unsubscribe from this group and stop receiving emails from it, send an email to haskell-core-libraries+unsubscribe at googlegroups.com.
>>>>> To view this discussion on the web visit https://groups.google.com/d/msgid/haskell-core-libraries/CAD34_kK6QgQ%2BQmg4NpTe%2B129ycFrOhTbcSHp_S9pX%3DdMh_DL%3Dg%40mail.gmail.com.
>>> _______________________________________________
>>> Libraries mailing list
>>> Libraries at haskell.org
>>> http://mail.haskell.org/cgi-bin/mailman/listinfo/libraries
>> 
>> -- 
>> You received this message because you are subscribed to the Google Groups "haskell-core-libraries" group.
>> To unsubscribe from this group and stop receiving emails from it, send an email to haskell-core-libraries+unsubscribe at googlegroups.com.
>> To view this discussion on the web visit https://groups.google.com/d/msgid/haskell-core-libraries/CAMgWh9tT%2BHJ1ZdGwzGuWmQXeQQGe6hWYWz3aEyhA13SMcu6OSw%40mail.gmail.com.
> 
> -- 
> You received this message because you are subscribed to the Google Groups "haskell-core-libraries" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to haskell-core-libraries+unsubscribe at googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/haskell-core-libraries/CAD34_kKcuBmJOikkKfpHKnGu0hD%3DUXDYAMbs655A-7FtZbGzUQ%40mail.gmail.com.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.haskell.org/pipermail/libraries/attachments/20191205/2fc31230/attachment.html>