Opened 3 years ago

Closed 3 years ago

#10113 closed feature request (fixed)

Re-export (<$>) and (<$) from Prelude

Reported by: hvr Owned by:
Priority: highest Milestone: 7.10.1
Component: libraries/base Version: 7.10.1-rc2
Keywords: AMP report-impact Cc: ekmett, thoughtpolice, hvr
Operating System: Unknown/Multiple Architecture: Unknown/Multiple
Type of failure: None/Unknown Test Case:
Blocked By: Blocking:
Related Tickets: #4834 Differential Rev(s): Phab:D680
Wiki Page:

Description

See http://thread.gmane.org/gmane.comp.lang.haskell.libraries/24161 for details

decision is still outstanding, but this needs to go into RC3 unless there's good reasons not to

Change History (6)

comment:1 Changed 3 years ago by hvr

Keywords: report-impact added

comment:2 Changed 3 years ago by Herbert Valerio Riedel <hvr@…>

In eb3661f2b9f8472f3714774126ebe1183484dd85/ghc:

Re-export `<$>` from Prelude (#10113)

Whether to re-export the `<$>` non-method operator from `Prelude` wasn't
explicitly covered in the original AMP proposal[1], but it turns out that
not doing so forces most code that makes use of applicatives to import
`Data.Functor` or `Control.Applicative` just to get that operator into
scope.  To this end, it was proposed to add `<$>` to Prelude as well[2].

The down-side is that this increases the amount of redundant-import
warnings triggered, as well as the relatively minor issue of stealing
the `<$>` operator from the default namespace for good (although at this
point `<$>` is supposed to be ubiquitous anyway due to `Applicative`
being implicitly required into the next Haskell Report)

 [1]: https://wiki.haskell.org/Functor-Applicative-Monad_Proposal
 [2]: http://thread.gmane.org/gmane.comp.lang.haskell.libraries/24161

Reviewed By: austin, ekmett

Differential Revision: https://phabricator.haskell.org/D680

comment:3 Changed 3 years ago by Herbert Valerio Riedel <hvr@…>

In 479523f3c37894d63352f1718e06696f3ed63143/ghc:

Re-export `<$` from Prelude (#10113)

This is a follow-up to eb3661f2b9f8472f3714774126ebe1183484dd85
re-exporting `<$` from `Prelude` as well.

Reviewed By: austin, ekmett

Differential Revision: https://phabricator.haskell.org/D681

comment:4 Changed 3 years ago by hvr

Summary: Re-export (<$>) from PreludeRe-export (<$>) and (<$) from Prelude

This was also merged to ghc-7.10 via dc737056fd66f6033cf6b7089a8508b62ab2eeb1 and 8601c74450a2a079ab1a8b67f18b503fae5b057b respectively

comment:5 Changed 3 years ago by thoughtpolice

Status: newmerge

comment:6 Changed 3 years ago by thoughtpolice

Resolution: fixed
Status: mergeclosed

Merged, thanks Herbert.

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