Function flat

flat([1, 2, [3, 4]]); // [1, 2, 3, 4]
Copy

Returns Iterable extends IsomorphicIterable<Item>
    ? Item extends IsomorphicIterable<SubItem>
        ? Item extends {
                [asyncIterator]() => AsyncIterator<SubItem, any, undefined>;
            }
            ? {
                [asyncIterator]() => AsyncIterableIterator<SubItem>;
                next(...args) => Promise<IteratorResult<SubItem, any>>;
                return?(value?) => Promise<IteratorResult<SubItem, any>>;
                throw?(e?) => Promise<IteratorResult<SubItem, any>>;
            }
            : {
                [iterator]() => IterableIterator<SubItem>;
                next(...args) => IteratorResult<SubItem, any>;
                return?(value?) => IteratorResult<SubItem, any>;
                throw?(e?) => IteratorResult<SubItem, any>;
            }
        : Iterable extends {
                [asyncIterator]() => AsyncIterator<Item, any, undefined>;
            }
            ? {
                [asyncIterator]() => AsyncIterableIterator<Item>;
                next(...args) => Promise<IteratorResult<Item, any>>;
                return?(value?) => Promise<IteratorResult<Item, any>>;
                throw?(e?) => Promise<IteratorResult<Item, any>>;
            }
            : {
                [iterator]() => IterableIterator<Item>;
                next(...args) => IteratorResult<Item, any>;
                return?(value?) => IteratorResult<Item, any>;
                throw?(e?) => IteratorResult<Item, any>;
            }
    : never

Iterable with flatten items.