asyncGroup

The asyncGroup() function groups values from an async iterable into an object of arrays with asynchronous grouping logic.

Interactive example

Syntax

Classic signature

function asyncGroup<
	GenericElement extends unknown,
	GenericOutput extends GroupFunctionOutput,
>(
	asyncIterator: AsyncIterable<GenericElement>,
	theFunction: (
		element: GenericElement,
		params: GroupFunctionParams
	) => MaybePromise<GenericOutput>,
): Promise<GroupResult<GenericOutput>>

Curried signature

function asyncGroup<
	GenericElement extends unknown,
	GenericOutput extends GroupFunctionOutput,
>(
	theFunction: (
		element: GenericElement,
		params: GroupFunctionParams
	) => MaybePromise<GenericOutput>,
): (asyncIterator: AsyncIterable<GenericElement>) => Promise<GroupResult<GenericOutput>>

Parameters

• asyncIterator: The async iterable source to group.
• theFunction: Async grouping function that receives:
• element: The current element.
• params.index: The current index.
• params.output(group, value): Helper to build a typed group output.

Return value

A Promise resolving to an object where each key is a group name and each value is an array of grouped values. Keys are optional because a group can be absent in the final result.

See also

• group - Synchronous version of asyncGroup
• asyncReduce - Reduces async iterables to a single value