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| author | Jade Lovelace <jadel@mercury.com> | 2022-10-31 17:16:31 -0700 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2022-11-08 12:55:18 -0500 |
| commit | 132f89089cc463172329b8f8766ad5c799ce2058 (patch) | |
| tree | 3fff8d7869509dbe0c5bc3e37cd5ae96e6414653 | |
| parent | ce726cd2a3182006999c57eff73368ab9a4f7c60 (diff) | |
| download | haskell-132f89089cc463172329b8f8766ad5c799ce2058.tar.gz | |
Clarify msum/asum documentation
| -rw-r--r-- | libraries/base/Data/Foldable.hs | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/libraries/base/Data/Foldable.hs b/libraries/base/Data/Foldable.hs index e2d792a1f2..084d846be2 100644 --- a/libraries/base/Data/Foldable.hs +++ b/libraries/base/Data/Foldable.hs @@ -1175,7 +1175,7 @@ sequence_ = foldr c (return ()) where c m k = m >> k {-# INLINE c #-} --- | The sum of a collection of actions, generalizing 'concat'. +-- | The sum of a collection of actions using '(<|>)', generalizing 'concat'. -- -- 'asum' is just like 'msum', but generalised to 'Alternative'. -- @@ -1189,10 +1189,16 @@ asum :: (Foldable t, Alternative f) => t (f a) -> f a {-# INLINE asum #-} asum = foldr (<|>) empty --- | The sum of a collection of actions, generalizing 'concat'. +-- | The sum of a collection of actions using '(<|>)', generalizing 'concat'. -- -- 'msum' is just like 'asum', but specialised to 'MonadPlus'. -- +-- ==== __Examples__ +-- +-- Basic usage, using the 'MonadPlus' instance for 'Maybe': +-- +-- >>> msum [Just "Hello", Nothing, Just "World"] +-- Just "Hello" msum :: (Foldable t, MonadPlus m) => t (m a) -> m a {-# INLINE msum #-} msum = asum |