Function flatMap

flatMap<V, R>(
input: V[],
mapper: (value: V, index: number) => Promise<Iterable<R, any, any>>,
): Promise<R[]>
Maps each element to an iterable, then flattens one level — preserving the original container type.

When the mapper returns a Promise, the function returns a Promise of the resulting container.
Type Parameters
- V
- R
Parameters
- input: V[]
- mapper: (value: V, index: number) => Promise<Iterable<R, any, any>>
Returns Promise<R[]>
Example
```
flatMap([1, 2, 3], v => [v, v]) // [1, 1, 2, 2, 3, 3]
await flatMap([1, 2], async v => [v, v + 10]) // [1, 11, 2, 12]
```
- Defined in src/iterable.ts:327
flatMap<V, R>(input: V[], mapper: (value: V, index: number) => Iterable<R>): R[]
Maps each element to an iterable, then flattens one level — preserving the original container type.

When the mapper returns a Promise, the function returns a Promise of the resulting container.
Type Parameters
- V
- R
Parameters
- input: V[]
- mapper: (value: V, index: number) => Iterable<R>
Returns R[]
Example
```
flatMap([1, 2, 3], v => [v, v]) // [1, 1, 2, 2, 3, 3]
await flatMap([1, 2], async v => [v, v + 10]) // [1, 11, 2, 12]
```
- Defined in src/iterable.ts:331
flatMap<K, V, K2, V2>(
    input: Map<K, V>,
    mapper: (
        value: [K, V],
        index: number,
    ) => Promise<Iterable<[K2, V2], any, any>>,
): Promise<Map<K2, V2>>
Maps each element to an iterable, then flattens one level — preserving the original container type.

When the mapper returns a Promise, the function returns a Promise of the resulting container.
Type Parameters
- K
- V
- K2
- V2
Parameters
- input: Map<K, V>
- mapper: (value: [K, V], index: number) => Promise<Iterable<[K2, V2], any, any>>
Returns Promise<Map<K2, V2>>
Example
```
flatMap([1, 2, 3], v => [v, v]) // [1, 1, 2, 2, 3, 3]
await flatMap([1, 2], async v => [v, v + 10]) // [1, 11, 2, 12]
```
- Defined in src/iterable.ts:335
flatMap<K, V, K2, V2>(
input: Map<K, V>,
mapper: (value: [K, V], index: number) => Iterable<[K2, V2]>,
): Map<K2, V2>
Maps each element to an iterable, then flattens one level — preserving the original container type.

When the mapper returns a Promise, the function returns a Promise of the resulting container.
Type Parameters
- K
- V
- K2
- V2
Parameters
- input: Map<K, V>
- mapper: (value: [K, V], index: number) => Iterable<[K2, V2]>
Returns Map<K2, V2>
Example
```
flatMap([1, 2, 3], v => [v, v]) // [1, 1, 2, 2, 3, 3]
await flatMap([1, 2], async v => [v, v + 10]) // [1, 11, 2, 12]
```
- Defined in src/iterable.ts:339
flatMap<T, R>(
input: Set<T>,
mapper: (value: T, index: number) => Promise<Iterable<R, any, any>>,
): Promise<Set<R>>
Maps each element to an iterable, then flattens one level — preserving the original container type.

When the mapper returns a Promise, the function returns a Promise of the resulting container.
Type Parameters
- T
- R
Parameters
- input: Set<T>
- mapper: (value: T, index: number) => Promise<Iterable<R, any, any>>
Returns Promise<Set<R>>
Example
```
flatMap([1, 2, 3], v => [v, v]) // [1, 1, 2, 2, 3, 3]
await flatMap([1, 2], async v => [v, v + 10]) // [1, 11, 2, 12]
```
- Defined in src/iterable.ts:343
flatMap<T, R>(
input: Set<T>,
mapper: (value: T, index: number) => Iterable<R>,
): Set<R>
Maps each element to an iterable, then flattens one level — preserving the original container type.

When the mapper returns a Promise, the function returns a Promise of the resulting container.
Type Parameters
- T
- R
Parameters
- input: Set<T>
- mapper: (value: T, index: number) => Iterable<R>
Returns Set<R>
Example
```
flatMap([1, 2, 3], v => [v, v]) // [1, 1, 2, 2, 3, 3]
await flatMap([1, 2], async v => [v, v + 10]) // [1, 11, 2, 12]
```
- Defined in src/iterable.ts:347
flatMap<T, R>(
    input: AsyncIterable<T>,
    mapper: (
        value: T,
        index: number,
    ) =>
        | AsyncIterable<R, any, any>
        | Iterable<R, any, any>
        | Promise<AsyncIterable<R, any, any> | Iterable<R, any, any>>,
): AsyncIterable<R>
Maps each element to an iterable, then flattens one level — preserving the original container type.

When the mapper returns a Promise, the function returns a Promise of the resulting container.
Type Parameters
- T
- R
Parameters
- input: AsyncIterable<T>
- mapper: (
      value: T,
      index: number,
  ) =>
      | AsyncIterable<R, any, any>
      | Iterable<R, any, any>
      | Promise<AsyncIterable<R, any, any> | Iterable<R, any, any>>
Returns AsyncIterable<R>
Example
```
flatMap([1, 2, 3], v => [v, v]) // [1, 1, 2, 2, 3, 3]
await flatMap([1, 2], async v => [v, v + 10]) // [1, 11, 2, 12]
```
- Defined in src/iterable.ts:351
flatMap<T, R>(
input: Iterable<T>,
mapper: (value: T, index: number) => Promise<Iterable<R, any, any>>,
): Promise<Iterable<R, any, any>>
Maps each element to an iterable, then flattens one level — preserving the original container type.

When the mapper returns a Promise, the function returns a Promise of the resulting container.
Type Parameters
- T
- R
Parameters
- input: Iterable<T>
- mapper: (value: T, index: number) => Promise<Iterable<R, any, any>>
Returns Promise<Iterable<R, any, any>>
Example
```
flatMap([1, 2, 3], v => [v, v]) // [1, 1, 2, 2, 3, 3]
await flatMap([1, 2], async v => [v, v + 10]) // [1, 11, 2, 12]
```
- Defined in src/iterable.ts:361
flatMap<T, R>(
input: Iterable<T>,
mapper: (value: T, index: number) => Iterable<R>,
): Iterable<R>
Maps each element to an iterable, then flattens one level — preserving the original container type.

When the mapper returns a Promise, the function returns a Promise of the resulting container.
Type Parameters
- T
- R
Parameters
- input: Iterable<T>
- mapper: (value: T, index: number) => Iterable<R>
Returns Iterable<R>
Example
```
flatMap([1, 2, 3], v => [v, v]) // [1, 1, 2, 2, 3, 3]
await flatMap([1, 2], async v => [v, v + 10]) // [1, 11, 2, 12]
```
- Defined in src/iterable.ts:365
flatMap<K extends PropertyKey, V, K2 extends PropertyKey, V2>(
input: Record<K, V>,
mapper: (value: [K, V], index: number) => Iterable<[K2, V2]>,
): Record<K2, V2>
Maps each element to an iterable, then flattens one level — preserving the original container type.

When the mapper returns a Promise, the function returns a Promise of the resulting container.
Type Parameters
- K extends PropertyKey
- V
- K2 extends PropertyKey
- V2
Parameters
- input: Record<K, V>
- mapper: (value: [K, V], index: number) => Iterable<[K2, V2]>
Returns Record<K2, V2>
Example
```
flatMap([1, 2, 3], v => [v, v]) // [1, 1, 2, 2, 3, 3]
await flatMap([1, 2], async v => [v, v + 10]) // [1, 11, 2, 12]
```
- Defined in src/iterable.ts:369
flatMap<K extends PropertyKey, V, K2 extends PropertyKey, V2>(
    input: Record<K, V>,
    mapper: (
        value: [K, V],
        index: number,
    ) => Promise<Iterable<[K2, V2], any, any>>,
): Promise<Record<K2, V2>>
Maps each element to an iterable, then flattens one level — preserving the original container type.

When the mapper returns a Promise, the function returns a Promise of the resulting container.
Type Parameters
- K extends PropertyKey
- V
- K2 extends PropertyKey
- V2
Parameters
- input: Record<K, V>
- mapper: (value: [K, V], index: number) => Promise<Iterable<[K2, V2], any, any>>
Returns Promise<Record<K2, V2>>
Example
```
flatMap([1, 2, 3], v => [v, v]) // [1, 1, 2, 2, 3, 3]
await flatMap([1, 2], async v => [v, v + 10]) // [1, 11, 2, 12]
```
- Defined in src/iterable.ts:373

Function flatMap

Type Parameters

Parameters

Returns Promise<R[]>

Example

Type Parameters

Parameters

Returns R[]

Example

Type Parameters

Parameters

Returns Promise<Map<K2, V2>>

Example

Type Parameters

Parameters

Returns Map<K2, V2>

Example

Type Parameters

Parameters

Returns Promise<Set<R>>

Example

Type Parameters

Parameters

Returns Set<R>

Example

Type Parameters

Parameters

Returns AsyncIterable<R>

Example

Type Parameters

Parameters

Returns Promise<Iterable<R, any, any>>

Example

Type Parameters

Parameters

Returns Iterable<R>

Example

Type Parameters

Parameters

Returns Record<K2, V2>

Example

Type Parameters

Parameters

Returns Promise<Record<K2, V2>>

Example

Settings