nothing -package:ghc
Analogous to
Nothing and equivalent to
mzero
nothing :: Prism' (Maybe a) ()
A prism on the
Nothing element of a
Maybe.
Match nothing, universal rejector.
>>> prove $ \(s :: SString) -> sNot (s `match` nothing)
Q.E.D.
Record with polymorphic phantom type of SQL null value. Semantics of
comparing is unsafe.
Assert that some value is Nothing.
A predicate checking if the input is Nothing
>>> Nothing `shouldSatisfy` P.nothing
This doesn't modify the config in any way. It's just here for your
initial config because Haskell doesn't allow empty do-blocks. Feel
free to delete it once you've added other stuff.
A Predicate that accepts
Maybe values of
Nothing. Unlike
eq, this doesn't require
Eq or
Show instances.
>>> accept nothing Nothing
True
>>> accept nothing (Just "something")
False
base Prelude Data.Maybe GHC.Maybe,
hedgehog Hedgehog.Internal.Prelude,
base-compat Prelude.Compat,
strict Data.Strict.Maybe,
protolude Protolude,
haskell-gi-base Data.GI.Base.ShortPrelude,
relude Relude.Monad.Reexport,
rio RIO.Prelude.Types,
base-prelude BasePrelude BasePrelude.DataTypes,
classy-prelude ClassyPrelude,
numeric-prelude NumericPrelude NumericPrelude.Base,
Cabal-syntax Distribution.Compat.Prelude,
basic-prelude CorePrelude,
universum Universum.Monad.Reexport,
ihaskell IHaskellPrelude,
basement Basement.Compat.Base Basement.Imports,
numhask NumHask.Prelude,
clash-prelude Clash.HaskellPrelude,
foundation Foundation,
ghc-lib-parser GHC.Data.Strict GHC.Prelude.Basic,
prelude-compat Prelude2010,
ghc-internal GHC.Internal.Data.Maybe GHC.Internal.Maybe,
dimensional Numeric.Units.Dimensional.Prelude,
rebase Rebase.Prelude,
quaalude Essentials,
mixed-types-num Numeric.MixedTypes.PreludeHiding,
xmonad-contrib XMonad.Config.Prime,
yaya Yaya.Pattern,
constrained-categories Control.Category.Constrained.Prelude Control.Category.Hask,
copilot-language Copilot.Language.Prelude,
incipit-base Incipit.Base,
LambdaHack Game.LambdaHack.Core.Prelude,
cabal-install-solver Distribution.Solver.Compat.Prelude,
faktory Faktory.Prelude,
protobuf-simple Data.ProtoBufInt,
strict-base-types Data.Maybe.Strict,
vcr Imports,
verset Verset,
yesod-paginator Yesod.Paginator.Prelude,
distribution-opensuse OpenSuse.Prelude,
termonad Termonad.Prelude
nothing_ :: Traversal' (Maybe a) ()
Traversal on the
Nothing element of a
Maybe.
Gets the nothing action.
This is an action that does nothing and where activating it always
fails.
Throw an exception with an error string associated with an
unsuccessful return code, otherwise return unit.
Return the error string associated with an unsuccessful return code,
otherwise Nothing