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  1. (<$>) :: Functor f => (a -> b) -> f a -> f b

    shelly Shelly

    An infix synonym for fmap. The name of this operator is an allusion to $. Note the similarities between their types:

    ($)  ::              (a -> b) ->   a ->   b
    (<$>) :: Functor f => (a -> b) -> f a -> f b
    
    Whereas $ is function application, <$> is function application lifted over a Functor.

    Examples

    Convert from a Maybe Int to a Maybe String using show:
    >>> show <$> Nothing
    Nothing
    
    >>> show <$> Just 3
    Just "3"
    
    Convert from an Either Int Int to an Either Int String using show:
    >>> show <$> Left 17
    Left 17
    
    >>> show <$> Right 17
    Right "17"
    
    Double each element of a list:
    >>> (*2) <$> [1,2,3]
    [2,4,6]
    
    Apply even to the second element of a pair:
    >>> even <$> (2,2)
    (2,True)
    

  2. (<$>) :: Functor f => (a -> b) -> f a -> f b

    shelly Shelly.Lifted

    An infix synonym for fmap. The name of this operator is an allusion to $. Note the similarities between their types:

    ($)  ::              (a -> b) ->   a ->   b
    (<$>) :: Functor f => (a -> b) -> f a -> f b
    
    Whereas $ is function application, <$> is function application lifted over a Functor.

    Examples

    Convert from a Maybe Int to a Maybe String using show:
    >>> show <$> Nothing
    Nothing
    
    >>> show <$> Just 3
    Just "3"
    
    Convert from an Either Int Int to an Either Int String using show:
    >>> show <$> Left 17
    Left 17
    
    >>> show <$> Right 17
    Right "17"
    
    Double each element of a list:
    >>> (*2) <$> [1,2,3]
    [2,4,6]
    
    Apply even to the second element of a pair:
    >>> even <$> (2,2)
    (2,True)
    

  3. (<$>) :: Functor f => (a -> b) -> f a -> f b

    shelly Shelly.Pipe

    An infix synonym for fmap. The name of this operator is an allusion to $. Note the similarities between their types:

    ($)  ::              (a -> b) ->   a ->   b
    (<$>) :: Functor f => (a -> b) -> f a -> f b
    
    Whereas $ is function application, <$> is function application lifted over a Functor.

    Examples

    Convert from a Maybe Int to a Maybe String using show:
    >>> show <$> Nothing
    Nothing
    
    >>> show <$> Just 3
    Just "3"
    
    Convert from an Either Int Int to an Either Int String using show:
    >>> show <$> Left 17
    Left 17
    
    >>> show <$> Right 17
    Right "17"
    
    Double each element of a list:
    >>> (*2) <$> [1,2,3]
    [2,4,6]
    
    Apply even to the second element of a pair:
    >>> even <$> (2,2)
    (2,True)
    

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

    turtle Turtle

    An infix synonym for fmap. The name of this operator is an allusion to $. Note the similarities between their types:

    ($)  ::              (a -> b) ->   a ->   b
    (<$>) :: Functor f => (a -> b) -> f a -> f b
    
    Whereas $ is function application, <$> is function application lifted over a Functor.

    Examples

    Convert from a Maybe Int to a Maybe String using show:
    >>> show <$> Nothing
    Nothing
    
    >>> show <$> Just 3
    Just "3"
    
    Convert from an Either Int Int to an Either Int String using show:
    >>> show <$> Left 17
    Left 17
    
    >>> show <$> Right 17
    Right "17"
    
    Double each element of a list:
    >>> (*2) <$> [1,2,3]
    [2,4,6]
    
    Apply even to the second element of a pair:
    >>> even <$> (2,2)
    (2,True)
    

  5. (<$>^) :: (a -> b) -> f a -> Aps f b

    ap-normalize ApNormalize

    f <$>^ u :: Aps f b is a delayed representation of f <$> u :: f b, so that it can be fused with other applicative operations. f <$>^ u is a shorthand for f <$> liftAps u.

  6. (<$>^) :: (a -> b) -> f a -> Aps f b

    ap-normalize ApNormalize.Aps

    f <$>^ u :: Aps f b is a delayed representation of f <$> u :: f b, so that it can be fused with other applicative operations. f <$>^ u is a shorthand for f <$> liftAps u.

  7. (<$) :: Functor f => a -> f b -> f a

    base-prelude BasePrelude.Operators

    Replace all locations in the input with the same value. The default definition is fmap . const, but this may be overridden with a more efficient version.

    Examples

    Perform a computation with Maybe and replace the result with a constant value if it is Just:
    >>> 'a' <$ Just 2
    Just 'a'
    
    >>> 'a' <$ Nothing
    Nothing
    

  8. (<$>) :: Functor f => (a -> b) -> f a -> f b

    base-prelude BasePrelude.Operators

    An infix synonym for fmap. The name of this operator is an allusion to $. Note the similarities between their types:

    ($)  ::              (a -> b) ->   a ->   b
    (<$>) :: Functor f => (a -> b) -> f a -> f b
    
    Whereas $ is function application, <$> is function application lifted over a Functor.

    Examples

    Convert from a Maybe Int to a Maybe String using show:
    >>> show <$> Nothing
    Nothing
    
    >>> show <$> Just 3
    Just "3"
    
    Convert from an Either Int Int to an Either Int String using show:
    >>> show <$> Left 17
    Left 17
    
    >>> show <$> Right 17
    Right "17"
    
    Double each element of a list:
    >>> (*2) <$> [1,2,3]
    [2,4,6]
    
    Apply even to the second element of a pair:
    >>> even <$> (2,2)
    (2,True)
    

  9. (>$) :: Contravariant f => b -> f b -> f a

    base-prelude BasePrelude.Operators

    Replace all locations in the output with the same value. The default definition is contramap . const, but this may be overridden with a more efficient version.

  10. (>$$<) :: Contravariant f => f b -> (a -> b) -> f a

    base-prelude BasePrelude.Operators

    This is an infix version of contramap with the arguments flipped.

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