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  1. mapMaybe :: List l => (a -> Maybe b) -> l a -> l b

    List Data.List.Class

    No documentation available.

  2. SchemaMaybe :: SchemaType' s ty -> SchemaType' s ty

    aeson-schemas Data.Aeson.Schema.Type

    No documentation available.

  3. addMaybeProxy :: Maybe Proxy -> Request -> Request

    authenticate-oauth Web.Authenticate.OAuth

    No documentation available.

  4. addMaybeProxy :: Maybe Proxy -> Request -> Request

    authenticate-oauth Web.Authenticate.OAuth.IO

    No documentation available.

  5. bumpMaybe :: a -> (a -> b -> b) -> (a -> b) -> Maybe b -> Maybe b

    backprop Numeric.Backprop.Internal

    No documentation available.

  6. mapMaybe :: (a -> Maybe b) -> Trie a -> Maybe (Trie b)

    bcp47 Data.BCP47.Trie

    No documentation available.

  7. mapMaybe :: (a -> Maybe b) -> Trie a -> Maybe (Trie b)

    bcp47 Data.BCP47.Trie.Internal

    No documentation available.

  8. mapMaybe2 :: (a -> Maybe b) -> Trie2 a -> Maybe (Trie2 b)

    bcp47 Data.BCP47.Trie.Internal

    No documentation available.

  9. catMaybes :: [Maybe a] -> [a]

    cabal-install-solver Distribution.Solver.Compat.Prelude

    The catMaybes function takes a list of Maybes and returns a list of all the Just values.

    Examples

    Basic usage: 
    >>> catMaybes [Just 1, Nothing, Just 3]
[1,3]
    When constructing a list of Maybe values, catMaybes can be used to return all of the "success" results (if the list is the result of a map, then mapMaybe would be more appropriate): 
    >>> import GHC.Internal.Text.Read ( readMaybe )

>>> [readMaybe x :: Maybe Int | x <- ["1", "Foo", "3"] ]
[Just 1,Nothing,Just 3]

>>> catMaybes $ [readMaybe x :: Maybe Int | x <- ["1", "Foo", "3"] ]
[1,3]

  10. fromMaybe :: a -> Maybe a -> a

    cabal-install-solver Distribution.Solver.Compat.Prelude

    The fromMaybe function takes a default value and a Maybe value. If the Maybe is Nothing, it returns the default value; otherwise, it returns the value contained in the Maybe.

    Examples

    Basic usage: 
    >>> fromMaybe "" (Just "Hello, World!")
"Hello, World!"

    >>> fromMaybe "" Nothing
""
    Read an integer from a string using readMaybe. If we fail to parse an integer, we want to return 0 by default: 
    >>> import GHC.Internal.Text.Read ( readMaybe )

>>> fromMaybe 0 (readMaybe "5")
5

>>> fromMaybe 0 (readMaybe "")
0

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