[**@cprussin/option-result v2.0.1**](../README.md)

***

# Class: Option\<T\>

Defined in: [option.ts:15](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L15)

A type which represents values that may or may not be present, without using
`undefined` or `null`.

## Type Parameters

### T

`T` *extends* `NonNullable`\<`unknown`\>

if this Option contains a value, this is the type of the value

## Boolean operators

### and()

> **and**\<`U`\>(`this`, `other`): `Option`\<`U`\>

Defined in: [option.ts:233](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L233)

Takes another Option and returns it if `this` is `Some`, otherwise
returns `None`.

#### Type Parameters

##### U

`U` *extends* `object`

the type contained in the Option returned by `fn`

#### Parameters

##### this

`Option`\<`T`\>

##### other

`Option`\<`U`\>

an Option to return if `this` is `Some`

#### Returns

`Option`\<`U`\>

`other` if `this` is `Some`, `None` otherwise

#### See

 - [andThen](#andthen)
 - [andThenAsync](#andthenasync)
 - [or](#or)
 - [orElse](#orelse)
 - [orElseAsync](#orelseasync)
 - [xor](#xor)

***

### andThen()

> **andThen**\<`U`\>(`this`, `fn`): `Option`\<`U`\>

Defined in: [option.ts:208](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L208)

Takes a function which takes the value contained in `this` and returns a
new Option; calls it and returns the result if `this` is `Some`,
otherwise returns `None`.  Also sometimes known in other languages or
libraries as `flatmap` or `bind`.

#### Type Parameters

##### U

`U` *extends* `object`

the type contained in the Option returned by `fn`

#### Parameters

##### this

`Option`\<`T`\>

##### fn

(`value`) => `Option`\<`U`\>

a function that will be called with the value in `this` if
`this` is `Some`

#### Returns

`Option`\<`U`\>

the result of calling `fn` if `this` is `Some`, `None` otherwise

#### See

 - [and](#and)
 - [andThenAsync](#andthenasync)
 - [or](#or)
 - [orElse](#orelse)
 - [orElseAsync](#orelseasync)
 - [xor](#xor)

***

### andThenAsync()

> **andThenAsync**\<`U`\>(`this`, `fn`): `Promise`\<`Option`\<`U`\>\>

Defined in: [option.ts:258](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L258)

Takes a function which takes the value contained in `this` and returns a
promise which resolves to a new Option; calls it and returns the
result if `this` is `Some`, otherwise returns a promise which resolves to
`None`.  This is an async version of [andThen](#andthen).

#### Type Parameters

##### U

`U` *extends* `object`

the type contained in the Option returned by `fn`

#### Parameters

##### this

`Option`\<`T`\>

##### fn

(`value`) => `Promise`\<`Option`\<`U`\>\>

a function that will be called with the value in `this` if
`this` is `Some`

#### Returns

`Promise`\<`Option`\<`U`\>\>

the result of calling `fn` if `this` is `Some`, `None` otherwise

#### See

 - [and](#and)
 - [andThen](#andthen)
 - [or](#or)
 - [orElse](#orelse)
 - [orElseAsync](#orelseasync)
 - [xor](#xor)

***

### or()

> **or**(`this`, `other`): `Option`\<`T`\>

Defined in: [option.ts:303](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L303)

Takes another Option and returns it if `this` is `None`, otherwise
returns `this`.

#### Parameters

##### this

`Option`\<`T`\>

##### other

`Option`\<`T`\>

an Option to return if `this` is `None`

#### Returns

`Option`\<`T`\>

`other` if `this` is `None`, `this` otherwise

#### See

 - [and](#and)
 - [andThen](#andthen)
 - [andThenAsync](#andthenasync)
 - [orElse](#orelse)
 - [orElseAsync](#orelseasync)
 - [xor](#xor)

***

### orElse()

> **orElse**(`this`, `fn`): `Option`\<`T`\>

Defined in: [option.ts:282](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L282)

Takes a function that returns an Option; calls it and returns the
result if `this` is `None`, otherwise returns `this`.

#### Parameters

##### this

`Option`\<`T`\>

##### fn

() => `Option`\<`T`\>

a function that will be called if `this` is `None`

#### Returns

`Option`\<`T`\>

the result of calling `fn` if `this` is `None`, `this` otherwise

#### See

 - [and](#and)
 - [andThen](#andthen)
 - [andThenAsync](#andthenasync)
 - [or](#or)
 - [orElseAsync](#orelseasync)
 - [xor](#xor)

***

### orElseAsync()

> **orElseAsync**(`this`, `fn`): `Promise`\<`Option`\<`T`\>\>

Defined in: [option.ts:322](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L322)

Takes a function that returns a promise which resolves to a new Option; calls it and returns the result if `this` is `None`, otherwise
returns a promise which resolves to `this`.

#### Parameters

##### this

`Option`\<`T`\>

##### fn

() => `Promise`\<`Option`\<`T`\>\>

a function that will be called if `this` is `None`

#### Returns

`Promise`\<`Option`\<`T`\>\>

the result of calling `fn` if `this` is `None`, `this` otherwise

#### See

 - [and](#and)
 - [andThen](#andthen)
 - [andThenAsync](#andthenasync)
 - [or](#or)
 - [orElse](#orelse)
 - [xor](#xor)

***

### xor()

> **xor**(`this`, `other`): `Option`\<`T`\>

Defined in: [option.ts:348](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L348)

Takes another Option, if both `this` and the other Option
are either `Some` or `None`, returns `None`.  Otherwise, returns whichever
Option is `Some`.

#### Parameters

##### this

`Option`\<`T`\>

##### other

`Option`\<`T`\>

the other Option to compare with `this`

#### Returns

`Option`\<`T`\>

`None` if both `this` and `other` are either `Some` or `None`;
otherwise returns whichever Option is `Some`

#### See

 - [and](#and)
 - [andThen](#andthen)
 - [andThenAsync](#andthenasync)
 - [or](#or)
 - [orElse](#orelse)
 - [orElseAsync](#orelseasync)

## Constructing

### None()

> `static` **None**\<`T`\>(): `Option`\<`T`\>

Defined in: [option.ts:47](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L47)

Construct an empty Option.

#### Type Parameters

##### T

`T` *extends* `object`

the type contained by the Option

#### Returns

`Option`\<`T`\>

an empty Option

#### See

 - [Some](../functions/Some.md)
 - [wrap](#wrap)

***

### Some()

> `static` **Some**\<`T`\>(`value`): `Option`\<`T`\>

Defined in: [option.ts:34](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L34)

Construct an Option containing a value.

#### Type Parameters

##### T

`T` *extends* `object`

the type contained by the Option

#### Parameters

##### value

`T`

the value contained by the Option

#### Returns

`Option`\<`T`\>

an Option containing `value`

#### See

 - [None](../functions/None.md)
 - [wrap](#wrap)

***

### wrap()

> `static` **wrap**\<`T`\>(`value`): `Option`\<`NonNullable`\<`T`\>\>

Defined in: [option.ts:96](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L96)

Takes a value that could be `null` or `undefined` and converts it into an
Option.

#### Type Parameters

##### T

`T`

the type contained by the Option values

#### Parameters

##### value

`T`

the nullable value

#### Returns

`Option`\<`NonNullable`\<`T`\>\>

`None` if `value` is `null` or `undefined`, `Some` containing
`value` otherwise

#### See

 - [Some](../functions/Some.md)
 - [None](../functions/None.md)

## Extracting the contained value

### match()

> **match**\<`U`\>(`this`, `matchers`): `U`

Defined in: [option.ts:135](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L135)

Takes two functions, one is called with the contained value if `this` is
`Some` and the other is called if `this` is `None`.

#### Type Parameters

##### U

`U`

the type of the return value of the matcher functions

#### Parameters

##### this

`Option`\<`T`\>

##### matchers

an object containing matcher functions

###### None

() => `U`

A function that will be called if `this` is `None`.

###### Some

(`value`) => `U`

A function that will be called on the value contained if `this` is
`Some`.

#### Returns

`U`

the return value of the `Some` or `None` matcher function

#### See

 - [unwrapOrElse](#unwraporelse)
 - [unwrapOr](#unwrapor)

***

### unwrapOr()

> **unwrapOr**(`this`, `defaultValue`): `T`

Defined in: [option.ts:186](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L186)

Returns the contained value if `this` is `Some`, otherwise return the
provided default value.

#### Parameters

##### this

`Option`\<`T`\>

##### defaultValue

`T`

the value to return if `this` is `None`

#### Returns

`T`

the contained if `this` is `Some`, otherwise `defaultValue`

#### See

 - [unwrapOrElse](#unwraporelse)
 - [match](#match)

***

### unwrapOrElse()

> **unwrapOrElse**(`this`, `defaultValue`): `T`

Defined in: [option.ts:169](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L169)

Returns the contained value if `this` is `Some`, otherwise call the
provided function and return the result.

#### Parameters

##### this

`Option`\<`T`\>

##### defaultValue

() => `T`

a function that will be called if `this` is `None`

#### Returns

`T`

the contained if `this` is `Some`, otherwise the return value from
calling `defaultValue`

#### See

 - [unwrapOr](#unwrapor)
 - [match](#match)

## Interacting with Result

### okOr()

> **okOr**\<`E`\>(`this`, `error`): [`Result`](Result.md)\<`T`, `E`\>

Defined in: [option.ts:537](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L537)

If `this` is a `Some`, return an [Result.Ok](Result.md#ok-2) with the contained
value.  Otherwise, return an [Result.Err](Result.md#err-2) containing the passed
default error value.

#### Type Parameters

##### E

`E` *extends* `object`

the type of `error` (and the error type of the returned
[Result](Result.md))

#### Parameters

##### this

`Option`\<`T`\>

##### error

`E`

an error value to use if `this` is `None`

#### Returns

[`Result`](Result.md)\<`T`, `E`\>

[Result.Ok](Result.md#ok-2) containing the value in `this` if `this` is
`Some`, otherwise [Result.Err](Result.md#err-2) containing `error`

#### See

 - [okOrElse](#okorelse)
 - [transpose](#transpose)

***

### okOrElse()

> **okOrElse**\<`E`\>(`this`, `error`): [`Result`](Result.md)\<`T`, `E`\>

Defined in: [option.ts:513](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L513)

If `this` is a `Some`, return an [Result.Ok](Result.md#ok-2) with the contained
value.  Otherwise, return an [Result.Err](Result.md#err-2) with the value returned by
calling the passed function.

#### Type Parameters

##### E

`E` *extends* `object`

the return type of `fn` (and the error type of the returned
[Result](Result.md))

#### Parameters

##### this

`Option`\<`T`\>

##### error

() => `E`

a function which returns an error value to use if `this` is
`None`

#### Returns

[`Result`](Result.md)\<`T`, `E`\>

[Result.Ok](Result.md#ok-2) containing the value in `this` if `this` is
`Some`, otherwise [Result.Err](Result.md#err-2) containing the value returned by
`error`

#### See

 - [okOr](#okor)
 - [transpose](#transpose)

***

### transpose()

> **transpose**\<`T`, `E`\>(`this`): [`Result`](Result.md)\<`Option`\<`T`\>, `E`\>

Defined in: [option.ts:559](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L559)

Convert an Option containing a [Result](Result.md) into a [Result](Result.md)
containing an Option.

#### Type Parameters

##### T

`T` *extends* `object`

the type of the value contained in the [Result](Result.md)
contained in `this`

##### E

`E` *extends* `object`

the error type of the [Result](Result.md) contained in `this`

#### Parameters

##### this

`Option`\<[`Result`](Result.md)\<`T`, `E`\>\>

#### Returns

[`Result`](Result.md)\<`Option`\<`T`\>, `E`\>

if `this` is `None`, returns [Result.Ok](Result.md#ok-2) containing `None`;
if `this` is `Some` and the [Result](Result.md) in `this` is [Result.Err](Result.md#err-2),
returns the [Result.Err](Result.md#err-2); otherwise returns [Result.Ok](Result.md#ok-2)
containing `Some` containing the value in the [Result](Result.md) in `this`

#### See

 - [okOr](#okor)
 - [okOrElse](#okorelse)

## Querying the variant

### isNone()

> **isNone**(`this`): `boolean`

Defined in: [option.ts:120](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L120)

Check if `this` is `None`.

#### Parameters

##### this

`Option`\<`T`\>

#### Returns

`boolean`

true if `this` is `None`, `false` otherwise

#### See

[isSome](#issome)

***

### isSome()

> **isSome**(`this`): `boolean`

Defined in: [option.ts:109](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L109)

Check if `this` is `Some`.

#### Parameters

##### this

`Option`\<`T`\>

#### Returns

`boolean`

true if `this` is `Some`, `false` otherwise

#### See

[isNone](#isnone)

## Transforming contained values

### filter()

> **filter**(`this`, `fn`): `Option`\<`T`\>

Defined in: [option.ts:442](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L442)

If `this` is `None`, returns `None`.  Otherwise, calls the predicate on the
value contained in `this`; if the predicate returns `true` then `this` is
returned, if the predicate returns `false` then `None` is returned.

#### Parameters

##### this

`Option`\<`T`\>

##### fn

(`value`) => `boolean`

the predicate function

#### Returns

`Option`\<`T`\>

`None` if `this` is `None` or if `fn` returns `false` when applied
to the value in `this`, `this` otherwise

#### See

 - [map](#map)
 - [mapAsync](#mapasync)
 - [mapOr](#mapor)
 - [zip](#zip)
 - [unzip](#unzip)

***

### map()

> **map**\<`U`\>(`this`, `fn`): `Option`\<`U`\>

Defined in: [option.ts:368](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L368)

Transforms `Option<T>` to `Option<U>` by applying the provided function to
the contained value of `Some` and leaving `None` values unchanged.

#### Type Parameters

##### U

`U` *extends* `object`

the type of the return value of `fn`

#### Parameters

##### this

`Option`\<`T`\>

##### fn

(`value`) => `U`

the function to apply to the value contained if `this` is `Some`

#### Returns

`Option`\<`U`\>

`None` if `this` is `None`, otherwise `Some` containing the result
of applying `fn` to the value in `this`

#### See

 - [mapAsync](#mapasync)
 - [mapOr](#mapor)
 - [filter](#filter)
 - [zip](#zip)
 - [unzip](#unzip)
 - [collect](#collect)

***

### mapAsync()

> **mapAsync**\<`U`\>(`this`, `fn`): `Promise`\<`Option`\<`U`\>\>

Defined in: [option.ts:394](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L394)

Transforms `Option<T>` to `Promise<Option<U>>` by applying the provided
async function to the contained value of `Some` and resolving `None` values
unchanged.

#### Type Parameters

##### U

`U` *extends* `object`

the type of the value in the promise returned by `fn`

#### Parameters

##### this

`Option`\<`T`\>

##### fn

(`value`) => `Promise`\<`U`\>

the function to apply to the value contained if `this` is
`Some`

#### Returns

`Promise`\<`Option`\<`U`\>\>

a promise resolving to `None` if `this` is `None`, otherwise a
promise resolving to `Some` containing the value resolved by the promise
returned from applying `fn` to the value in `this`

#### See

 - [map](#map)
 - [mapOr](#mapor)
 - [filter](#filter)
 - [zip](#zip)
 - [unzip](#unzip)
 - [collect](#collect)

***

### mapOr()

> **mapOr**\<`U`\>(`this`, `defaultValue`, `fn`): `U`

Defined in: [option.ts:419](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L419)

Applies the provided function to the contained value if `this` is `Some`,
otherwise returns the provided default value.

#### Type Parameters

##### U

`U` *extends* `object`

the type of `defaultValue` and the value returned by `fn`

#### Parameters

##### this

`Option`\<`T`\>

##### defaultValue

`U`

the value to return if `this` is `None`

##### fn

(`value`) => `U`

the function to apply to the value contained if `this` is
`Some`

#### Returns

`U`

the result of applying `fn` to the value in `this` if `this` is
`Some`, otherwise `defaultValue`

#### See

 - [map](#map)
 - [mapAsync](#mapasync)
 - [filter](#filter)
 - [zip](#zip)
 - [unzip](#unzip)
 - [collect](#collect)

***

### unzip()

> **unzip**\<`T`, `U`\>(`this`): readonly \[`Option`\<`T`\>, `Option`\<`U`\>\]

Defined in: [option.ts:488](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L488)

Called on an Option containing a tuple -- if `this` is `Some`,
returns a tuple of `Some` containing the contained values. Otherwise,
returns a tuple of `None`.

#### Type Parameters

##### T

`T` *extends* `object`

the type of the first value in the tuple in `this`

##### U

`U` *extends* `object`

the type of the second value in the tuple in `this`

#### Parameters

##### this

`Option`\<readonly \[`T`, `U`\]\>

#### Returns

readonly \[`Option`\<`T`\>, `Option`\<`U`\>\]

a tuple of `Some` containing the values in the tuple contained in
`this` if `this` is `Some`, a tuple of `None` otherwise

#### See

 - [map](#map)
 - [mapAsync](#mapasync)
 - [mapOr](#mapor)
 - [filter](#filter)
 - [zip](#zip)

***

### zip()

> **zip**\<`U`\>(`this`, `other`): `Option`\<readonly \[`T`, `U`\]\>

Defined in: [option.ts:462](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L462)

Takes another Option, if both Option values are `Some`,
returns a `Some` containing a tuple of the contained values.  Otherwise
returns `None`.

#### Type Parameters

##### U

`U` *extends* `object`

the type of the value in `other`

#### Parameters

##### this

`Option`\<`T`\>

##### other

`Option`\<`U`\>

the other Option to zip with `this`

#### Returns

`Option`\<readonly \[`T`, `U`\]\>

`Some` containing a tuple with the values in `this` and `other` if
both `this` and `other` are `Some`, `None` otherwise

#### See

 - [map](#map)
 - [mapAsync](#mapasync)
 - [mapOr](#mapor)
 - [filter](#filter)
 - [unzip](#unzip)

***

### collect()

> `static` **collect**\<`T`\>(`options`): `Option`\<`T`[]\>

Defined in: [option.ts:70](https://github.com/cprussin/cprussin-monorepo/blob/45be92bc13a41d9f46c6ab9ed2d9a61167827e46/packages/option-result/src/option.ts#L70)

Takes an Array of Option values.  If any of the Option
values in the array is `None`, returns `None`.  Otherwise, returns `Some`
containing an Array of each value inside each Option in the
original list.

#### Type Parameters

##### T

`T` *extends* `object`

the type contained by the Option values

#### Parameters

##### options

`Option`\<`T`\>[]

the Option values to collect

#### Returns

`Option`\<`T`[]\>

`Some` containing an Array of values contained by each Option in the original Array if all Option values in the original
list are `Some`, `None` otherwise

#### See

 - [map](#map)
 - [mapAsync](#mapasync)
 - [mapOr](#mapor)
 - [filter](#filter)
 - [zip](#zip)
 - [unzip](#unzip)