alias for toLeft
alias for toRight
Catamorphism.
Catamorphism. Run the given function on the underlying value if present, otherwise return the provided fallback value
Return true
if this is a Maybe.Just and the underlying value
satisfies the provided predicate
Tag with Tags.First
Return true
if this is a Maybe.Empty or if this is a Maybe.Just
and the underlying value satisfies the provided predicate
Return the underlying value if present, otherwise the provided fallback value
True if no underlying value is present
True if an underlying value is present
Tag with Tags.Last
Tag with Tags.Max
Tag with Tags.Min
Return this instance if it is a Maybe.Just, otherwise the provided fallback
Return the underlying value wrapped in type F
if present, otherwise the
empty value for type F
Return the underlying value if present, otherwise the monoid zero
Turn the underlying value into a failure validation if present, otherwise return a success validation with the provided fallback value
Turn the underlying value into a left disjunction if present, otherwise return a right disjunction with the provided fallback value
Convert to a standard library Option
Turn the underlying value into a right disjunction if present, otherwise return a left disjunction with the provided fallback value
Turn the underlying value into a success validation if present, otherwise return a failure validation with the provided fallback value
alias for orZero
alias for getOrElse
An optional value
A
Maybe[A]
will either be a wrappedA
instance (Just[A]
), or a lack of underlyingA
instance (Empty[A]
).Maybe[A]
is isomorphic toOption[A]
, however there are some differences between the two.Maybe
is invariant inA
whileOption
is covariant.Maybe[A]
does not expose an unsafeget
operation to access the underlyingA
value (that may not exist) likeOption[A]
does.Maybe[A]
does not come with an implicit conversion toIterable[A]
(a trait with over a dozen super types).