import type { IsomorphicIterable } from "@vangware/types";
import type { ReadOnlyAsyncIterable } from "./types/ReadOnlyAsyncIterable.js";
import type { ReadOnlyAsyncIterableIterator } from "./types/ReadOnlyAsyncIterableIterator.js";
import type { ReadOnlyIterableIterator } from "./types/ReadOnlyIterableIterator.js";
/**
 * Flattens one level of the given iterable or asynchronous iterable.
 *
 * @category Generators
 * @example
 * ```typescript
 * flat([1, 2, [3, 4]]); // [1, 2, 3, 4]
 * ```
 * @param iterable Iterable to flatten.
 * @returns Iterable with flatten items.
 */
export declare const flat: <Iterable_1 extends IsomorphicIterable>(
	iterable: Iterable_1,
) => Iterable_1 extends IsomorphicIterable<infer Item>
	? Item extends IsomorphicIterable<infer SubItem>
		? Item extends {
				readonly [Symbol.asyncIterator]: () => AsyncIterator<
					SubItem,
					any,
					undefined
				>;
		  }
			? {
					readonly [Symbol.asyncIterator]: () => AsyncIterableIterator<SubItem>;
					readonly next: (
						...args: [] | [undefined]
					) => Promise<IteratorResult<SubItem, any>>;
					readonly return?:
						| ((
								value?: any,
						  ) => Promise<IteratorResult<SubItem, any>>)
						| undefined;
					readonly throw?:
						| ((e?: any) => Promise<IteratorResult<SubItem, any>>)
						| undefined;
			  }
			: {
					readonly [Symbol.iterator]: () => IterableIterator<SubItem>;
					readonly next: (
						...args: [] | [undefined]
					) => IteratorResult<SubItem, any>;
					readonly return?:
						| ((value?: any) => IteratorResult<SubItem, any>)
						| undefined;
					readonly throw?:
						| ((e?: any) => IteratorResult<SubItem, any>)
						| undefined;
			  }
		: Iterable_1 extends {
				readonly [Symbol.asyncIterator]: () => AsyncIterator<
					Item,
					any,
					undefined
				>;
		  }
		? {
				readonly [Symbol.asyncIterator]: () => AsyncIterableIterator<Item>;
				readonly next: (
					...args: [] | [undefined]
				) => Promise<IteratorResult<Item, any>>;
				readonly return?:
					| ((value?: any) => Promise<IteratorResult<Item, any>>)
					| undefined;
				readonly throw?:
					| ((e?: any) => Promise<IteratorResult<Item, any>>)
					| undefined;
		  }
		: {
				readonly [Symbol.iterator]: () => IterableIterator<Item>;
				readonly next: (
					...args: [] | [undefined]
				) => IteratorResult<Item, any>;
				readonly return?:
					| ((value?: any) => IteratorResult<Item, any>)
					| undefined;
				readonly throw?:
					| ((e?: any) => IteratorResult<Item, any>)
					| undefined;
		  }
	: never;