Class None<T>

Type parameters

T

Hierarchy

Opt<T>
- None

Index

Properties

@@type

Accessors

Methods

Properties

Readonly @@type

@@type: symbol = noneSymbol

Accessors

isEmpty

get isEmpty(): boolean

Overrides Opt.isEmpty
- Defined in Opt.ts:383
Returns boolean

length

get length(): number

Inherited from Opt.length
- Defined in Opt.ts:23
1 for Some, 0 for None.

Returns number

nonEmpty

get nonEmpty(): boolean

Inherited from Opt.nonEmpty
- Defined in Opt.ts:18
false for Some, true for None.

Returns boolean

Methods

bimap

bimap<U>(_someF: (_: T) => U, noneF: () => U): Opt<U>

Overrides Opt.bimap
- Defined in Opt.ts:426
Type parameters
- U
Parameters
- _someF: (_: T) => U
  - - (_: T): U
    - Parameters
      - _: T
      Returns U
- noneF: () => U
  - - (): U
    - Returns U
Returns Opt<U>

caseOf

caseOf<R>(_onSome: (x: T) => R, onNone: () => R): R

Overrides Opt.caseOf
- Defined in Opt.ts:405
Type parameters
- R
Parameters
- _onSome: (x: T) => R
  - - (x: T): R
    - Parameters
      - x: T
      Returns R
- onNone: () => R
  - - (): R
    - Returns R
Returns R

chain

chain<U>(f: (_: T) => Opt<U>): Opt<U>

Inherited from Opt.chain
- Defined in Opt.ts:76
Alias of flatMap

Type parameters
- U
Parameters
- f: (_: T) => Opt<U>
  - - (_: T): Opt<U>
    - Parameters
      - _: T
      Returns Opt<U>
Returns Opt<U>

chainToOpt

chainToOpt<U>(f: (_: T) => U | undefined | null): Opt<U>

Inherited from Opt.chainToOpt
- Defined in Opt.ts:88
Combination of flatMap and opt functions.
```
some(1).chainToOpt(x => x === 1 ? null : x + 1) // None
some(2).chainToOpt(x => x === 1 ? null : x + 1) // Some(3)
```
Type parameters
- U
Parameters
- f: (_: T) => U | undefined | null
  - - (_: T): U | undefined | null
    - Parameters
      - _: T
      Returns U | undefined | null
Returns Opt<U>

contains

contains(_x: T): boolean

Overrides Opt.contains
- Defined in Opt.ts:416
Parameters
- _x: T
Returns boolean

exists

exists(_p: (x: T) => boolean): boolean

Overrides Opt.exists
- Defined in Opt.ts:418
Parameters
- _p: (x: T) => boolean
  - - (x: T): boolean
    - Parameters
      - x: T
      Returns boolean
Returns boolean

filter

filter(_predicate: (_: T) => boolean): Opt<T>

Overrides Opt.filter
- Defined in Opt.ts:440
Parameters
- _predicate: (_: T) => boolean
  - - (_: T): boolean
    - Parameters
      - _: T
      Returns boolean
Returns Opt<T>

flatBimap

flatBimap<U>(_someF: (_: T) => Opt<U>, noneF: () => Opt<U>): Opt<U>

Overrides Opt.flatBimap
- Defined in Opt.ts:428
Type parameters
- U
Parameters
- _someF: (_: T) => Opt<U>
  - - (_: T): Opt<U>
    - Parameters
      - _: T
      Returns Opt<U>
- noneF: () => Opt<U>
  - - (): Opt<U>
    - Returns Opt<U>
Returns Opt<U>

flatMap

flatMap<U>(_f: (_: T) => Opt<U>): Opt<U>

Overrides Opt.flatMap
- Defined in Opt.ts:387
Type parameters
- U
Parameters
- _f: (_: T) => Opt<U>
  - - (_: T): Opt<U>
    - Parameters
      - _: T
      Returns Opt<U>
Returns Opt<U>

forAll

forAll(_p: (x: T) => boolean): boolean

Overrides Opt.forAll
- Defined in Opt.ts:420
Parameters
- _p: (x: T) => boolean
  - - (x: T): boolean
    - Parameters
      - x: T
      Returns boolean
Returns boolean

map

map<U>(): Opt<U>

Overrides Opt.map
- Defined in Opt.ts:389
Type parameters
- U
Returns Opt<U>

narrow

narrow<U>(_guard: (value: any) => value is U): Opt<U>

Overrides Opt.narrow
- Defined in Opt.ts:442
Type parameters
- U
Parameters
- _guard: (value: any) => value is U
  - - (value: any): value is U
    - Parameters
      - value: any
      Returns value is U
Returns Opt<U>

noneIf

noneIf(predicate: (_: T) => boolean): Opt<T>

Inherited from Opt.noneIf
- Defined in Opt.ts:354
Returns None if predicate holds, otherwise passes same instance of Opt.
```
opt(1).noneIf(x => x > 0); // None
opt(-1).noneIf(x => x > 0); // Some(-1)
```
see

filter
Parameters
- predicate: (_: T) => boolean
  - - (_: T): boolean
    - Parameters
      - _: T
      Returns boolean
Returns Opt<T>

onNone

onNone(f: () => void): Opt<T>

Overrides Opt.onNone
- Defined in Opt.ts:409
Parameters
- f: () => void
  - - (): void
    - Returns void
Returns Opt<T>

onSome

onSome(_f: (x: T) => void): Opt<T>

Overrides Opt.onSome
- Defined in Opt.ts:414
Parameters
- _f: (x: T) => void
  - - (x: T): void
    - Parameters
      - x: T
      Returns void
Returns Opt<T>

optOrCrash

optOrCrash(msg: string): Opt<T>

Overrides Opt.optOrCrash
- Defined in Opt.ts:393
Parameters
- msg: string
Returns Opt<T>

orCrash

orCrash(msg: string): T

Overrides Opt.orCrash
- Defined in Opt.ts:391
Parameters
- msg: string
Returns T

orElse

orElse(def: T): T

Overrides Opt.orElse
- Defined in Opt.ts:422
Parameters
- def: T
Returns T

orElseOpt

orElseOpt(def: Opt<T>): Opt<T>

Overrides Opt.orElseOpt
- Defined in Opt.ts:424
Parameters
- def: Opt<T>
Returns Opt<T>

orFalse

orFalse(): false | T

Overrides Opt.orFalse
- Defined in Opt.ts:399
Returns false | T

orNaN

orNaN(): number | T

Overrides Opt.orNaN
- Defined in Opt.ts:403
Returns number | T

orNull

orNull(): T | null

Overrides Opt.orNull
- Defined in Opt.ts:395
Returns T | null

orTrue

orTrue(): true | T

Overrides Opt.orTrue
- Defined in Opt.ts:401
Returns true | T

orUndef

orUndef(): T | undefined

Overrides Opt.orUndef
- Defined in Opt.ts:397
Returns T | undefined

pipe

pipe<R>(f: (x: Opt<T>) => R): R

Inherited from Opt.pipe
- Defined in Opt.ts:194
Applies passed function to this instance and returns function result. Also known as a function application, |> or pipe operator.
```
some(1).pipe(x => x.isEmpty) // false
none.pipe(x => x.isEmpty) // true
```
Type parameters
- R
Parameters
- f: (x: Opt<T>) => R
  - - (x: Opt<T>): R
    - Parameters
      - x: Opt<T>
      Returns R
Returns R

print

print(tag?: undefined | string): Opt<T>

Overrides Opt.print
- Defined in Opt.ts:444
Parameters
- Optional tag: undefined | string
Returns Opt<T>

toArray

toArray(): [] | [T]

Overrides Opt.toArray
- Defined in Opt.ts:385
Returns [] | [T]

toString

toString(): string

Overrides Opt.toString
- Defined in Opt.ts:430
Returns string

zip

zip<U>(_other: Opt<U>): Opt<[T, U]>

Overrides Opt.zip
- Defined in Opt.ts:432
Type parameters
- U
Parameters
- _other: Opt<U>
Returns Opt<[T, U]>

zip3

zip3<X, Y>(_x: Opt<X>, _y: Opt<Y>): Opt<[T, X, Y]>

Overrides Opt.zip3
- Defined in Opt.ts:434
Type parameters
- X
- Y
Parameters
- _x: Opt<X>
- _y: Opt<Y>
Returns Opt<[T, X, Y]>

zip4

zip4<X, Y, Z>(_x: Opt<X>, _y: Opt<Y>, _z: Opt<Z>): Opt<[T, X, Y, Z]>

Overrides Opt.zip4
- Defined in Opt.ts:436
Type parameters
- X
- Y
- Z
Parameters
- _x: Opt<X>
- _y: Opt<Y>
- _z: Opt<Z>
Returns Opt<[T, X, Y, Z]>

zip5

zip5<X, Y, Z, ZZ>(_x: Opt<X>, _y: Opt<Y>, _z: Opt<Z>, _zz: Opt<ZZ>): Opt<[T, X, Y, Z, ZZ]>

Overrides Opt.zip5
- Defined in Opt.ts:438
Type parameters
- X
- Y
- Z
- ZZ
Parameters
- _x: Opt<X>
- _y: Opt<Y>
- _z: Opt<Z>
- _zz: Opt<ZZ>
Returns Opt<[T, X, Y, Z, ZZ]>

Static fromArray

fromArray<T>(x: [] | [T]): Opt<T>

Inherited from Opt.fromArray
- Defined in Opt.ts:35
Create Opt instance from an array of one or zero items.
```
Opt.fromArray([]) // None
Opt.fromArray([1]) // Some(1)
```
Type parameters
- T
Parameters
- x: [] | [T]
Returns Opt<T>

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