From 5643ecf97150805032203bd9c8c92b5ded54d724 Mon Sep 17 00:00:00 2001
From: Bodigrim <andrew.lelechenko@gmail.com>
Date: Wed, 15 Nov 2023 19:23:31 +0000
Subject: [PATCH] Update changelog and since annotations for
Data.List.NonEmpty.permutations
Approved by CLC in https://github.com/haskell/core-libraries-committee/issues/68#issuecomment-1221409837
---
libraries/base/changelog.md | 1 +
libraries/base/src/Data/List/NonEmpty.hs | 10 +++++++++-
.../tests/interface-stability/base-exports.stdout | 2 ++
.../base-exports.stdout-javascript-unknown-ghcjs | 2 ++
.../interface-stability/base-exports.stdout-mingw32 | 2 ++
.../interface-stability/base-exports.stdout-ws-32 | 2 ++
6 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/libraries/base/changelog.md b/libraries/base/changelog.md
index f2b04008bf4f..ff16d96caf5a 100644
--- a/libraries/base/changelog.md
+++ b/libraries/base/changelog.md
@@ -2,6 +2,7 @@
## 4.20.0.0 *TBA*
* Export `foldl'` from `Prelude` ([CLC proposal #167](https://github.com/haskell/core-libraries-committee/issues/167))
+ * Add `permutations` and `permutations1` to `Data.List.NonEmpty` ([CLC proposal #68](https://github.com/haskell/core-libraries-committee/issues/68))
* Add a `RULE` to `Prelude.lookup`, allowing it to participate in list fusion ([CLC proposal #174](https://github.com/haskell/core-libraries-committee/issues/175))
* The `Enum Int64` and `Enum Word64` instances now use native operations on 32-bit platforms, increasing performance by up to 1.5x on i386 and up to 5.6x with the JavaScript backend. ([CLC proposal #187](https://github.com/haskell/core-libraries-committee/issues/187))
* Update to [Unicode 15.1.0](https://www.unicode.org/versions/Unicode15.1.0/).
diff --git a/libraries/base/src/Data/List/NonEmpty.hs b/libraries/base/src/Data/List/NonEmpty.hs
index 7617fcde6ed5..55f1ef5df282 100644
--- a/libraries/base/src/Data/List/NonEmpty.hs
+++ b/libraries/base/src/Data/List/NonEmpty.hs
@@ -444,6 +444,8 @@ groupAllWith1 :: (Ord b) => (a -> b) -> NonEmpty a -> NonEmpty (NonEmpty a)
groupAllWith1 f = groupWith1 f . sortWith f
-- | The 'permutations' function returns the list of all permutations of the argument.
+--
+-- @since 4.20.0.0
permutations :: [a] -> NonEmpty [a]
permutations xs0 = xs0 :| perms xs0 []
where
@@ -453,9 +455,15 @@ permutations xs0 = xs0 :| perms xs0 []
interleave' _ [] r = (ts, r)
interleave' f (y:ys) r = let (us,zs) = interleave' (f . (y:)) ys r
in (y:us, f (t:y:us) : zs)
+-- The implementation of 'permutations' is adopted from 'Data.List.permutations',
+-- see there for discussion and explanations.
-- | 'permutations1' operates like 'permutations', but uses the knowledge that its input is
--- non-empty to produce output which every element is non-empty.
+-- non-empty to produce output where every element is non-empty.
+--
+-- > permutations1 = fmap fromList . permutations . toList
+--
+-- @since 4.20.0.0
permutations1 :: NonEmpty a -> NonEmpty (NonEmpty a)
permutations1 xs = fromList <$> permutations (toList xs)
diff --git a/testsuite/tests/interface-stability/base-exports.stdout b/testsuite/tests/interface-stability/base-exports.stdout
index dfa7eaee1e32..5baeb36a1629 100644
--- a/testsuite/tests/interface-stability/base-exports.stdout
+++ b/testsuite/tests/interface-stability/base-exports.stdout
@@ -1410,6 +1410,8 @@ module Data.List.NonEmpty where
nub :: forall a. GHC.Classes.Eq a => NonEmpty a -> NonEmpty a
nubBy :: forall a. (a -> a -> GHC.Types.Bool) -> NonEmpty a -> NonEmpty a
partition :: forall a. (a -> GHC.Types.Bool) -> NonEmpty a -> ([a], [a])
+ permutations :: forall a. [a] -> NonEmpty [a]
+ permutations1 :: forall a. NonEmpty a -> NonEmpty (NonEmpty a)
prependList :: forall a. [a] -> NonEmpty a -> NonEmpty a
repeat :: forall a. a -> NonEmpty a
reverse :: forall a. NonEmpty a -> NonEmpty a
diff --git a/testsuite/tests/interface-stability/base-exports.stdout-javascript-unknown-ghcjs b/testsuite/tests/interface-stability/base-exports.stdout-javascript-unknown-ghcjs
index 5763d7741f4a..06dfff22ceed 100644
--- a/testsuite/tests/interface-stability/base-exports.stdout-javascript-unknown-ghcjs
+++ b/testsuite/tests/interface-stability/base-exports.stdout-javascript-unknown-ghcjs
@@ -1410,6 +1410,8 @@ module Data.List.NonEmpty where
nub :: forall a. GHC.Classes.Eq a => NonEmpty a -> NonEmpty a
nubBy :: forall a. (a -> a -> GHC.Types.Bool) -> NonEmpty a -> NonEmpty a
partition :: forall a. (a -> GHC.Types.Bool) -> NonEmpty a -> ([a], [a])
+ permutations :: forall a. [a] -> NonEmpty [a]
+ permutations1 :: forall a. NonEmpty a -> NonEmpty (NonEmpty a)
prependList :: forall a. [a] -> NonEmpty a -> NonEmpty a
repeat :: forall a. a -> NonEmpty a
reverse :: forall a. NonEmpty a -> NonEmpty a
diff --git a/testsuite/tests/interface-stability/base-exports.stdout-mingw32 b/testsuite/tests/interface-stability/base-exports.stdout-mingw32
index d218a15cb9fc..568ee1b38327 100644
--- a/testsuite/tests/interface-stability/base-exports.stdout-mingw32
+++ b/testsuite/tests/interface-stability/base-exports.stdout-mingw32
@@ -1410,6 +1410,8 @@ module Data.List.NonEmpty where
nub :: forall a. GHC.Classes.Eq a => NonEmpty a -> NonEmpty a
nubBy :: forall a. (a -> a -> GHC.Types.Bool) -> NonEmpty a -> NonEmpty a
partition :: forall a. (a -> GHC.Types.Bool) -> NonEmpty a -> ([a], [a])
+ permutations :: forall a. [a] -> NonEmpty [a]
+ permutations1 :: forall a. NonEmpty a -> NonEmpty (NonEmpty a)
prependList :: forall a. [a] -> NonEmpty a -> NonEmpty a
repeat :: forall a. a -> NonEmpty a
reverse :: forall a. NonEmpty a -> NonEmpty a
diff --git a/testsuite/tests/interface-stability/base-exports.stdout-ws-32 b/testsuite/tests/interface-stability/base-exports.stdout-ws-32
index 060c25dafcc3..d0ea76eeced1 100644
--- a/testsuite/tests/interface-stability/base-exports.stdout-ws-32
+++ b/testsuite/tests/interface-stability/base-exports.stdout-ws-32
@@ -1410,6 +1410,8 @@ module Data.List.NonEmpty where
nub :: forall a. GHC.Classes.Eq a => NonEmpty a -> NonEmpty a
nubBy :: forall a. (a -> a -> GHC.Types.Bool) -> NonEmpty a -> NonEmpty a
partition :: forall a. (a -> GHC.Types.Bool) -> NonEmpty a -> ([a], [a])
+ permutations :: forall a. [a] -> NonEmpty [a]
+ permutations1 :: forall a. NonEmpty a -> NonEmpty (NonEmpty a)
prependList :: forall a. [a] -> NonEmpty a -> NonEmpty a
repeat :: forall a. a -> NonEmpty a
reverse :: forall a. NonEmpty a -> NonEmpty a
--
GitLab