Generalise (some of) Data.List to Foldables (re #9568)

This replaces the entities in Data.List conflicting with Data.Foldable
with re-exports of the generalised version from Data.Foldable.

As of this commit, the following compiles w/o error

    module XPrelude (module X) where

    import Control.Monad as X
    import Data.Foldable as X
    import Data.List as X
    import Prelude as X

Reviewed By: austin, dfeuer, ekmett

Differential Revision: https://phabricator.haskell.org/D229

2 files changed, 15 insertions, 2 deletions

diff --git a/libraries/base/Data/List.hs b/libraries/base/Data/List.hs
index 44c86bb7d8..5bc812194a 100644
--- a/libraries/base/Data/List.hs
+++ b/libraries/base/Data/List.hs
@@ -207,5 +207,8 @@ module Data.List
 
    ) where
 
-import Data.Foldable ()
-import Data.OldList
+import Data.Foldable
+import Data.OldList hiding ( all, and, any, concat, concatMap, elem, find,
+                             foldl, foldl1, foldl', foldr, foldr1, maximum,
+                             maximumBy, minimum, minimumBy, notElem, or,
+                             product, sum )
diff --git a/libraries/base/changelog.md b/libraries/base/changelog.md
index d82d354c91..c57d5f0e56 100644
--- a/libraries/base/changelog.md
+++ b/libraries/base/changelog.md
@@ -35,6 +35,16 @@
   * Turn `toList`, `elem`, `sum`, `product`, `maximum`, and `minimum`
     into `Foldable` methods (#9621)
 
+  * Replace the `Data.List`-exported functions
+
+    ```
+    all, and, any, concat, concatMap, elem, find, product, sum
+    ```
+
+    by re-exports of their generalised `Data.Foldable` counterparts.
+    In other words, unqualified imports of `Data.List` and
+    `Data.Foldable` no longer lead to conflicting definitions. (#9586)
+
 ## 4.7.0.1  *Jul 2014*
 
   * Bundled with GHC 7.8.3