null

null :: [a] -> Bool
base Prelude, base Data.List
Test whether a list is empty.
null :: ByteString -> Bool
bytestring Data.ByteString, bytestring Data.ByteString.Char8, bytestring Data.ByteString.Lazy, bytestring Data.ByteString.Lazy.Char8
O(1) Test whether a ByteString is empty.
null :: IntMap a -> Bool
containers Data.IntMap.Strict, containers Data.IntMap.Lazy
O(1). Is the map empty? > Data.IntMap.null (empty) == True > Data.IntMap.null (singleton 1 'a') == False
null :: IntSet -> Bool
containers Data.IntSet
O(1). Is the set empty?
null :: Map k a -> Bool
containers Data.Map.Lazy, containers Data.Map.Strict
O(1). Is the map empty? > Data.Map.null (empty) == True > Data.Map.null (singleton 1 'a') == False
null :: Seq a -> Bool
containers Data.Sequence
O(1). Is this the empty sequence?
null :: Set a -> Bool
containers Data.Set
O(1). Is this the empty set?
null :: Text -> Bool
text Data.Text, text Data.Text.Lazy
O(1) Tests whether a Text is empty or not. Subject to fusion.
nullFunPtr :: FunPtr a
base Foreign.Ptr
The constant nullFunPtr contains a distinguished value of FunPtr that is not associated with a valid memory location.
nullPtr :: Ptr a
base Foreign.Ptr
The constant nullPtr contains a distinguished value of Ptr that is not associated with a valid memory location.
package null-canvas
package
A Haskell port of the HTML5 Canvas API. blank-canvas works by providing a web service that displays the users' Haskell commands inside a browser. Version 0.2.7
nullFileMode :: FileMode
unix System.Posix.Files.ByteString, unix System.Posix.Files
No permissions.
nullHooks :: StreamHooks ty
HTTP Network.TCP
nullSignal :: Signal
unix System.Posix.Signals
nullURI :: URI
network Network.URI
Blank URI
Null :: DL
unix System.Posix.DynamicLinker.Prim
throwErrnoIfNull :: String -> IO (Ptr a) -> IO (Ptr a)
base Foreign.C.Error
Throw an IOError corresponding to the current value of getErrno if the IO action returns nullPtr.
throwErrnoIfNullRetry :: String -> IO (Ptr a) -> IO (Ptr a)
base Foreign.C.Error
Throw an IOError corresponding to the current value of getErrno if the IO action returns nullPtr, but retry in case of an interrupted operation.
throwErrnoIfNullRetryMayBlock :: String -> IO (Ptr a) -> IO b -> IO (Ptr a)
base Foreign.C.Error
as throwErrnoIfNullRetry, but checks for operations that would block.
throwErrnoPathIfNull :: String -> FilePath -> IO (Ptr a) -> IO (Ptr a)
base Foreign.C.Error, unix System.Posix.Error
as throwErrnoIfNull, but exceptions include the given path when appropriate.

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