nothing -package:lens-family

Analogous to Nothing and equivalent to mzero

NULL value.

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.

Nothing bound to the Maybe Int type encoded as an Expr. This is an alias to nothingInt.

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.

Return either a 'QExpr (Maybe x)' representing Nothing or a nullable Table or PrimaryKey filled with Nothing.

>>> runTP nothingBetweenZeroAndOne
Lemma: nothingBetweenZeroAndOne         Q.E.D.
[Proven] nothingBetweenZeroAndOne :: Ɐm ∷ Nat → Bool

The Opaleye analogue of Nothing.

The Opaleye analogue of const Nothing. Can be useful to avoid type inference problems, because it doesn't pick up a type class constraint.