None

A type that represents the absence of a value.

This type is not intended to be used or instantiated directly. Instead, None instances can be created with Optional.none and can then be manipulated with any method available on Optional.

Please see the Optional documentation for more information.

Note:

All None methods are documented at the Optional level.

Hierarchy

Optional<any>
- None

Index

Methods

and

and(other: Optional): Optional

Overrides Optional.and
- Defined in Optional.ts:723
Type parameters
- U
Parameters
- other: Optional
Returns Optional

ap

ap(func: Optional<function>): Optional<any>

Overrides Optional.ap
- Defined in Optional.ts:739
Parameters
- func: Optional<function>
Returns Optional<any>

filter

filter<T>(condition: function): Optional<T>

Overrides Optional.filter
- Defined in Optional.ts:747
Type parameters
- T
Parameters
- condition: function
 - - (val: T): boolean
 - Parameters
 - val: T
 Returns boolean
Returns Optional<T>

flatMap

flatMap<T, U>(func: function): Optional

Overrides Optional.flatMap
- Defined in Optional.ts:727
Type parameters
- T
- U
Parameters
- func: function
 - - (val: T): Optional
 - Parameters
 - val: T
 Returns Optional
Returns Optional

forEach

forEach(func: function): void

Overrides Optional.forEach
- Defined in Optional.ts:751
Parameters
- func: function
  - - (val: any): void
    - Parameters
      - val: any
      Returns void
Returns void

forceUnwrap

forceUnwrap(message?: undefined | string): never

Overrides Optional.forceUnwrap
- Defined in Optional.ts:695
Parameters
- Optional message: undefined | string
Returns never

isNone

isNone(): boolean

Overrides Optional.isNone
- Defined in Optional.ts:680
Returns boolean

isSome

isSome(): boolean

Overrides Optional.isSome
- Defined in Optional.ts:676
Returns boolean

map

map<T, U>(func: function): Optional

Overrides Optional.map
- Defined in Optional.ts:719
Type parameters
- T
- U
Parameters
- func: function
 - - (val: T): U
 - Parameters
 - val: T
 Returns U
Returns Optional

match

match<T, U, V>(options: OptMatch<T, U, V>): V | U

Overrides Optional.match
- Defined in Optional.ts:743
Type parameters
- T
- U
- V
Parameters
- options: OptMatch<T, U, V>
Returns V | U

or

or<T>(other: Optional<T>): Optional<T>

Overrides Optional.or
- Defined in Optional.ts:731
Type parameters
- T
Parameters
- other: Optional<T>
Returns Optional<T>

orElse

orElse<T>(func: function): Optional<T>

Overrides Optional.orElse
- Defined in Optional.ts:735
Type parameters
- T
Parameters
- func: function
 - - (): Optional<T>
 - Returns Optional<T>
Returns Optional<T>

toArray

toArray(): Array<any>

Overrides Optional.toArray
- Defined in Optional.ts:755
Returns Array<any>

toString

toString(): string

Overrides Optional.toString
- Defined in Optional.ts:684
Returns string

unwrap

unwrap(message?: undefined | string): never

Overrides Optional.unwrap
- Defined in Optional.ts:688
Parameters
- Optional message: undefined | string
Returns never

unwrapOr

unwrapOr<T>(other: T | function): T

Overrides Optional.unwrapOr
- Defined in Optional.ts:706
Type parameters
- T
Parameters
- other: T | function
Returns T

unwrapOrElse

unwrapOrElse<T>(func: function): T

Overrides Optional.unwrapOrElse
- Defined in Optional.ts:715
Type parameters
- T
Parameters
- func: function
  - - (): T
    - Returns T
Returns T

Static fromNullable

fromNullable<A>(value?: A): Optional<A>

Inherited from Optional.fromNullable
- Defined in Optional.ts:104
Creates an Optional with the given value. If null or undefined is provided a None will be returned, otherwise a Some containing the given value will be returned.
```
const one = Optional.fromNullable(1); // one.unwrapOr(0) === 1
const none = Optional.fromNullable(null); // none.unwrapOr(0) === 0
const nope = Optional.fromNullable(); // nope.unwrapOr(0) === 0
```
Type parameters
- A
 
 The type of the value that the new Optional will contain.
Parameters
- Optional value: A
 
 The value to create an Optional with.
Returns Optional<A>

Either a Some or a None depending on the value provided.

Static none

none(): Optional<any>

Inherited from Optional.none
- Defined in Optional.ts:86
Creates a None.
```
const nope = Optional.none();
// nope.unwrapOr(0) === 0
```
Returns Optional<any>

A None instance.

Static of

of<A>(value: A): Optional<A>

Inherited from Optional.of
- Defined in Optional.ts:56
Creates an Some with the given value.
```
const one = Optional.of(1);
// one.unwrapOr(0) === 1
```
Type parameters
- A
 
 The type of the value that the new Some will contain.
Parameters
- value: A
 
 A value to create a Some with.
Returns Optional<A>

A Some instance containing value.

Static some

some<A>(value: A): Optional<A>

Inherited from Optional.some
- Defined in Optional.ts:72
Creates a Some with the given value.
```
const one = Optional.some(1);
// one.unwrapOr(0) === 1
```
Type parameters
- A
 
 The type of the value that the new Some will contain.
Parameters
- value: A
 
 A value to create a Some with.
Returns Optional<A>

A Some instance containing value.

Generated using TypeDoc

None

Note:

Hierarchy

Index

Methods

Methods

and

Type parameters

U

Parameters

other: Optional<U>

Returns Optional<U>

ap

Parameters

func: Optional<function>

Returns Optional<any>

filter

Type parameters

T

Parameters

condition: function

Parameters

val: T

Returns boolean

Returns Optional<T>

flatMap

Type parameters

T

U

Parameters

func: function

Parameters

val: T

Returns Optional<U>

Returns Optional<U>

forEach

Parameters

func: function

Parameters

val: any

Returns void

Returns void

forceUnwrap

Parameters

Optional message: undefined | string

Returns never

isNone

Returns boolean

isSome

Returns boolean

map

Type parameters

T

U

Parameters

func: function

Parameters

val: T

Returns U

Returns Optional<U>

match

Type parameters

T

U

V

Parameters

options: OptMatch<T, U, V>

Returns V | U

or

Type parameters

T

Parameters

other: Optional<T>

Returns Optional<T>

orElse

Type parameters

T

Parameters

func: function

Returns Optional<T>