None

Represents an optional value. An Option is either a Some value containing a value, or a None value containing no value.

@example

let o: Option<number> = Option.some(42);
o = Option.none; // Marks the option as empty

Hierarchy

• Option<never>
  • None

Index

Properties

• instance

Accessors

• none

Methods

• all
• any
• assert
• is
• some
• unwrap

Properties

publicstaticreadonlyinstance

instance: None = ...

The singleton instance of None.

Prefer using Option.none instead.

Accessors

publicstaticnone

• get none(): Option<never>

• Inherited from Option.none

  Returns a None value.

  @example

  let o: Option<number> = Option.none;

  ---

  Returns Option<never>

Methods

publicstaticall

• all<T>(values: T): Option<{ -readonly [ K in string | number | symbol ]: OptionType<T[K<K>]> }>

• Inherited from Option.all

  Returns the array of Some values, if all are Some.

  @example

  const tuple = [Option.some(42), Option.some('42')] as const;
  Option.all(tuple); // Option<[number, string]>

  ---

  Type parameters

  • T: readonly Option<unknown>[]

  Parameters

  • values: T

  Returns Option<{ -readonly [ K in string | number | symbol ]: OptionType<T[K<K>]> }>

publicstaticany

• any<T>(values: T): Option<OptionType<T[number]>>

• Inherited from Option.any

  Returns the first Some value in the array, if any is Some.

  @example

  const tuple = [Option.none, Option.some(42), Option.some('42')] as const;
  Option.any(tuple); // Option<number | string>

  ---

  Type parameters

  • T: readonly Option<unknown>[]

  Parameters

  • values: T

  Returns Option<OptionType<T[number]>>

publicstaticassert

• assert<T>(option: Option<T>, type: typeof Some): asserts option is Some<T>
• assert<T>(option: Option<T>, type: typeof None): asserts option is None

• Inherited from Option.assert

  Asserts that the option is a Some value.

  @throws

  If the value is a None.

  ---

  Type parameters

  • T

  Parameters

  • option: Option<T>

  • type: typeof Some

  Returns asserts option is Some<T>

publicstaticis

• is<T>(option: Option<T>, type: typeof Some): option is Some<T>
• is<T>(option: Option<T>, type: typeof None): option is None

• Inherited from Option.is

  Returns true if the option is a Some value.

  ---

  Type parameters

  • T

  Parameters

  • option: Option<T>

  • type: typeof Some

  Returns option is Some<T>

publicstaticsome

• some<T>(value: T): Option<T>

• Inherited from Option.some

  Returns a Some value.

  @example

  let o: Option<number> = Option.some(42);

  ---

  Type parameters

  • T

  Parameters

  • value: T

  Returns Option<T>

publicstaticunwrap

• unwrap<T>(option: Option<T>): T

• Inherited from Option.unwrap

  Unwraps the option, yielding the content of a Some.

  @throws

  If the value is a None.

  ---

  Type parameters

  • T

  Parameters

  • option: Option<T>

  Returns T