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Within LTS Haskell 24.6 (ghc-9.10.2)
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deriving-compat Data.Deriving.Internal No documentation available.
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ghc-internal GHC.Internal.Data.Maybe The listToMaybe function returns Nothing on an empty list or Just a where a is the first element of the list.
Examples
Basic usage:>>> listToMaybe [] Nothing
>>> listToMaybe [9] Just 9
>>> listToMaybe [1,2,3] Just 1
Composing maybeToList with listToMaybe should be the identity on singleton/empty lists:>>> maybeToList $ listToMaybe [5] [5] >>> maybeToList $ listToMaybe [] []
But not on lists with more than one element:>>> maybeToList $ listToMaybe [1,2,3] [1]
listToDot :: PrintDot a => [a] -> DotCodegraphviz Data.GraphViz.Printing The quoted form of unqtListToDot; defaults to wrapping double quotes around the result of unqtListToDot (since the default implementation has characters that must be quoted).
listToDot :: PrintDot a => [a] -> DotCodegraphviz Data.GraphViz.Types The quoted form of unqtListToDot; defaults to wrapping double quotes around the result of unqtListToDot (since the default implementation has characters that must be quoted).
listofstringopt :: String -> RawOpts -> [String]hledger-lib Hledger.Data.RawOptions No documentation available.
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ghc-lib-parser GHC.Data.Bag No documentation available.
listToArray :: Int -> (e -> Int) -> (e -> a) -> [e] -> SmallArray aghc-lib-parser GHC.Data.SmallArray Convert a list into an array.
listUntilEoi :: Parser e s a -> Parser e s [a]bytesmith Data.Bytes.Parser Apply the parser repeatedly until there is no more input left to consume. Collects the results into a list.
listVars :: Typeable a => String -> a -> [Expr]express Data.Express Generate an infinite list of variables based on a template and a given type. (cf. listVarsAsTypeOf)
> putL 10 $ listVars "x" (undefined :: Int) [ x :: Int , y :: Int , z :: Int , x' :: Int , y' :: Int , z' :: Int , x'' :: Int , ... ]
> putL 10 $ listVars "p" (undefined :: Bool) [ p :: Bool , q :: Bool , r :: Bool , p' :: Bool , q' :: Bool , r' :: Bool , p'' :: Bool , ... ]
listVarsAsTypeOf :: String -> Expr -> [Expr]express Data.Express Generate an infinite list of variables based on a template and the type of a given Expr. (cf. listVars)
> let one = val (1::Int) > putL 10 $ "x" `listVarsAsTypeOf` one [ x :: Int , y :: Int , z :: Int , x' :: Int , ... ]
> let false = val False > putL 10 $ "p" `listVarsAsTypeOf` false [ p :: Bool , q :: Bool , r :: Bool , p' :: Bool , ... ]