concatMap()

Maps each outer value to an inner store and runs inners sequentially (queue while busy).

Signature

function concatMap<A, B>(fn: (value: A) => Store<B>): StoreOperator<A, B | undefined>
function concatMap<A, B>(
	fn: (value: A) => Store<B>,
	opts: { initial: B; maxBuffer?: number },
): StoreOperator<A, B>

Parameters

Parameter	Type	Description
fn	(value: A) => Store<B>	Inner store factory.
opts	{ initial?: B; maxBuffer?: number }	{ initial: B } narrows type; maxBuffer drops oldest queued outers when exceeded (default: unlimited).

Returns

StoreOperator<A, B | undefined> or B with initial.

Options / Behavior Details

• Tier 2: Reactive; no eager fn(outer.get()).

See Also

• switchMap
• exhaustMap