Class Optional<T>

An optional value of type T.

Construct using Optional.of or Optional.empty.

Collabs uses this utility type in places where T | undefined or T | null is inappropriate because T may itself be null/undefined.

Local data structure - not a Collab.

Type Parameters

T

Hierarchy

Optional

Index

Properties

isPresent

Methods

Properties

Readonly isPresent

isPresent: boolean

Whether the value is present.

Methods

get

get(): T

- Defined in core/build/esm/src/util/optional.d.ts:21
Returns the value if present, else throwing an error.

Returns T

map

map<U>(f: ((value: T) => U)): Optional<U>

- Defined in core/build/esm/src/util/optional.d.ts:31
Map the value by f if present, else returning an empty Optional.

Type Parameters
- U
Parameters
- f: ((value: T) => U)
  - - (value: T): U
    - Parameters
      - value: T
      Returns U
Returns Optional<U>

orElse

orElse(other: T): T

- Defined in core/build/esm/src/util/optional.d.ts:25
Returns the value if present, else returning other.

Parameters
- other: T
Returns T

toString

toString(): string

- Defined in core/build/esm/src/util/optional.d.ts:32
Returns string

Static empty

empty<T>(): Optional<T>

- Defined in core/build/esm/src/util/optional.d.ts:39
Returns an empty (not present) Optional.

Internally, all empty Optionals are the same literal object.

Type Parameters
- T
Returns Optional<T>

Static of

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

- Defined in core/build/esm/src/util/optional.d.ts:43
Returns a new present Optional representing value.

Type Parameters
- T
Parameters
- value: T
Returns Optional<T>

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