Hoogle Search

Within LTS Haskell 24.35 (ghc-9.10.3)

Note that Stackage only displays results for the latest LTS and Nightly snapshot. Learn more.

Exact lookup

1. data OrdMap k a

   morpheus-graphql-core	Data.Morpheus.Types.Internal.AST

   No documentation available.

2. module MathObj.DiscreteMap

   DiscreteMap was originally intended as a type class that unifies Map and Array. One should be able to simply choose between - Map for sparse arrays - Array for full arrays. However, the Edison package provides the class AssocX which already exists for that purpose. Currently I use this module for some numeric instances of Data.Map.

3. indexMapFromList :: C a => [(a, b)] -> Map (ToOrd a) b

   numeric-prelude	MathObj.PartialFraction

   No documentation available.

4. indexMapMapWithKey :: (a -> b -> c) -> Map (ToOrd a) b -> Map (ToOrd a) c

   numeric-prelude	MathObj.PartialFraction

   No documentation available.

5. indexMapToList :: Map (ToOrd a) b -> [(a, b)]

   numeric-prelude	MathObj.PartialFraction

   No documentation available.

6. scalarMap :: (Show v, C a v) => (a -> a) -> T a v -> T a v

   numeric-prelude	Number.OccasionallyScalarExpression

   No documentation available.

7. scalarMap2 :: (Show v, C a v) => (a -> a -> a) -> T a v -> T a v -> T a v

   numeric-prelude	Number.OccasionallyScalarExpression

   No documentation available.

8. concatMap :: Foldable t => (a -> [b]) -> t a -> [b]

   numeric-prelude	NumericPrelude

   Map a function over all the elements of a container and concatenate the resulting lists.

   Examples

   Basic usage:

   >>> concatMap (take 3) [[1..], [10..], [100..], [1000..]]
   [1,2,3,10,11,12,100,101,102,1000,1001,1002]
   

   >>> concatMap (take 3) (Just [1..])
   [1,2,3]
   

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

   numeric-prelude	NumericPrelude

   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)
   

10. concatMap :: Foldable t => (a -> [b]) -> t a -> [b]

    numeric-prelude	NumericPrelude.Base

    Map a function over all the elements of a container and concatenate the resulting lists.

    Examples

    Basic usage:

    >>> concatMap (take 3) [[1..], [10..], [100..], [1000..]]
    [1,2,3,10,11,12,100,101,102,1000,1001,1002]
    

    >>> concatMap (take 3) (Just [1..])
    [1,2,3]
    

Page 579 of many | Previous | Next