None<T> class

Means "no value"

Implemented types

Constructors

None()
Create None
const

Properties

has bool
Get whether it has Value
final
hashCode int
The hash code for this object. [...]
read-only, override
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited
val → T
Get the Value if it has
final

Methods

defaultVal(T v) Some<T>
Set a default value when it is None
override
defaultValFn(T fn()) Some<T>
Set a default value when it is None [...]
override
none<R>(R none()) Maybe<R>
When it not has Value Return Some(none(it)) [...]
override
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed. [...]
inherited
some<R>(R _(T val)) Maybe<R>
fMap [...]
override
toString() String
Returns a string representation of this object.
inherited
when<R>({R some(T val), R none()}) Maybe<R>
Pattern matching [...]
override

Operators

operator ==(dynamic other) bool
The equality operator. [...]
override