Function flatMap

flatMap<T, U>(
mapper: (value: T, context: OperatorContext) => Source<U>,
options?: HigherOrderOptions,
): Operator<T, U>
Maps each value synchronously to a child source and flattens the children concurrently.

Wrap asynchronous setup inside defer within the returned child source. Defaults to concurrency: 1.
Type Parameters
- T
- U
Parameters
- mapper: (value: T, context: OperatorContext) => Source<U>
- options: HigherOrderOptions = {}
Returns Operator<T, U>

Throws
If concurrency is not a positive safe integer.