Add PolyKinds extension to Data.Monoid
authorAlexander Berntsen <alexander@plaimi.net>
Sat, 19 Jul 2014 04:53:48 +0000 (23:53 -0500)
committerAustin Seipp <austin@well-typed.com>
Sun, 20 Jul 2014 21:55:51 +0000 (16:55 -0500)
commit18b2c46773eccb974bdd042a2f400edd23e193d7
tree4c71efad27cb1e10aee8e5cada1ba343bdf2c46f
parent893a4bf1ceb484dc20f5145ef9ae255c1f69db9b
Add PolyKinds extension to Data.Monoid

Summary:
Carl Howells pointed out[0] that the `Monoid` instance for
`Data.Proxy.Proxy` is only defined for types with kind *.

This is a very mild change. Furthermore, Edward Kmett revealed[1] that
it was supposed to be there all along -- the extension simply got lost
in commit 1d1ff77aaa09efaddc8cfe0dcf92d6763297cf11, as pointed out by
Adam Vogt[2]. This used to be correct in GHC 7.6, so this commit fixes a
regression.

This addresses #9317.

[0] <http://www.haskell.org/pipermail/libraries/2014-July/023261.html>.
[1] <http://www.haskell.org/pipermail/libraries/2014-July/023267.html>.
[2] <http://www.haskell.org/pipermail/libraries/2014-July/023265.html>.

Signed-off-by: Alexander Berntsen <alexander@plaimi.net>
Test Plan: See [0]

Reviewers: austin, hvr, ekmett

Reviewed By: austin, hvr, ekmett

Subscribers: phaskell, simonmar, relrod, carter

Differential Revision: https://phabricator.haskell.org/D70
libraries/base/Data/Monoid.hs
libraries/base/changelog.md