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1. mconcatMap :: Monoid b => (a -> b) -> [a] -> b

   extra	Extra

   Version on concatMap generalised to a Monoid rather than just a list.

   mconcatMap Sum [1,2,3] == Sum 6
   \f xs -> mconcatMap f xs == concatMap f xs
   

2. mconcatMapM :: (Monad m, Monoid b) => (a -> m b) -> [a] -> m b

   extra	Extra

   A version of mconcatMap that works with a monadic predicate.

3. bimap :: Bifunctor p => (a -> b) -> (c -> d) -> p a c -> p b d

   semigroupoids	Data.Bifunctor.Apply

   Map over both arguments at the same time.

   bimap f g ≡ first f . second g
   

   Examples

   >>> bimap toUpper (+1) ('j', 3)
   ('J',4)
   

   >>> bimap toUpper (+1) (Left 'j')
   Left 'J'
   

   >>> bimap toUpper (+1) (Right 3)
   Right 4
   

4. fmap :: Functor f => (a -> b) -> f a -> f b

   semigroupoids	Data.Functor.Apply

   fmap is used to apply a function of type (a -> b) to a value of type f a, where f is a functor, to produce a value of type f b. Note that for any type constructor with more than one parameter (e.g., Either), only the last type parameter can be modified with fmap (e.g., b in `Either a b`). Some type constructors with two parameters or more have a Bifunctor instance that allows both the last and the penultimate parameters to be mapped over.

   Examples

   Convert from a Maybe Int to a Maybe String using show:

   >>> fmap show Nothing
   Nothing
   
   >>> fmap show (Just 3)
   Just "3"
   

   Convert from an Either Int Int to an Either Int String using show:

   >>> fmap show (Left 17)
   Left 17
   
   >>> fmap show (Right 17)
   Right "17"
   

   Double each element of a list:

   >>> fmap (*2) [1,2,3]
   [2,4,6]
   

   Apply even to the second element of a pair:

   >>> fmap even (2,2)
   (2,True)
   

   It may seem surprising that the function is only applied to the last element of the tuple compared to the list example above which applies it to every element in the list. To understand, remember that tuples are type constructors with multiple type parameters: a tuple of 3 elements (a,b,c) can also be written (,,) a b c and its Functor instance is defined for Functor ((,,) a b) (i.e., only the third parameter is free to be mapped over with fmap). It explains why fmap can be used with tuples containing values of different types as in the following example:

   >>> fmap even ("hello", 1.0, 4)
   ("hello",1.0,True)
   

5. fmap :: Functor f => (a -> b) -> f a -> f b

   semigroupoids	Data.Functor.Bind

   fmap is used to apply a function of type (a -> b) to a value of type f a, where f is a functor, to produce a value of type f b. Note that for any type constructor with more than one parameter (e.g., Either), only the last type parameter can be modified with fmap (e.g., b in `Either a b`). Some type constructors with two parameters or more have a Bifunctor instance that allows both the last and the penultimate parameters to be mapped over.

   Examples

   Convert from a Maybe Int to a Maybe String using show:

   >>> fmap show Nothing
   Nothing
   
   >>> fmap show (Just 3)
   Just "3"
   

   Convert from an Either Int Int to an Either Int String using show:

   >>> fmap show (Left 17)
   Left 17
   
   >>> fmap show (Right 17)
   Right "17"
   

   Double each element of a list:

   >>> fmap (*2) [1,2,3]
   [2,4,6]
   

   Apply even to the second element of a pair:

   >>> fmap even (2,2)
   (2,True)
   

   It may seem surprising that the function is only applied to the last element of the tuple compared to the list example above which applies it to every element in the list. To understand, remember that tuples are type constructors with multiple type parameters: a tuple of 3 elements (a,b,c) can also be written (,,) a b c and its Functor instance is defined for Functor ((,,) a b) (i.e., only the third parameter is free to be mapped over with fmap). It explains why fmap can be used with tuples containing values of different types as in the following example:

   >>> fmap even ("hello", 1.0, 4)
   ("hello",1.0,True)
   

6. bifoldMap1 :: (Bifoldable1 t, Semigroup m) => (a -> m) -> (b -> m) -> t a b -> m

   semigroupoids	Data.Semigroup.Bifoldable

   No documentation available.

7. bifoldMapDefault1 :: (Bifoldable1 t, Monoid m) => (a -> m) -> (b -> m) -> t a b -> m

   semigroupoids	Data.Semigroup.Bifoldable

   Usable default for foldMap, but only if you define bifoldMap1 yourself

8. bifoldMap1Default :: (Bitraversable1 t, Semigroup m) => (a -> m) -> (b -> m) -> t a b -> m

   semigroupoids	Data.Semigroup.Bitraversable

   No documentation available.

9. foldMap1 :: (Foldable1 t, Semigroup m) => (a -> m) -> t a -> m

   semigroupoids	Data.Semigroup.Foldable

   Map each element of the structure to a semigroup, and combine the results with (<>). This fold is right-associative and lazy in the accumulator. For strict left-associative folds consider foldMap1' instead.

   >>> foldMap1 (:[]) (1 :| [2, 3, 4])
   [1,2,3,4]
   

10. foldMapDefault1 :: (Foldable1 t, Monoid m) => (a -> m) -> t a -> m

    semigroupoids	Data.Semigroup.Foldable

    Usable default for foldMap, but only if you define foldMap1 yourself

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