/**
 * Copyright 2021 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/**
 * A wrapper around the native iterator that provides a better API.
 *
 * @example
 * ```js
 * const slothActivities = [`sleeping`, `eating`, `climbing`]
 *
 * const iterator = Betterator.fromIterable(slothActivities)
 * while (iterator.hasNext()) {
 *   console.log(iterator.getNext())
 * }
 * //=> sleeping
 * //=> eating
 * //=> climbing
 * ```
 */
declare class Betterator<Value> {
    /** Constructs an {@link Betterator} from `iterator`. */
    constructor(iterator: Iterator<Value>);
    /**
     * Returns `true` if the underlying native iterator of this {@link Betterator}
     * has been exhausted. Otherwise, returns `false`.
     *
     * This method may call the underlying native iterator's `next` method.
     */
    hasNext(): boolean;
    /**
     * Returns the next element of the underlying native iterator.
     *
     * @throws if the underlying native iterator does not have a next element.
     */
    getNext(): Value;
    /**
     * Returns the next element of the underlying native iterator if it has a next
     * element. Otherwise, it returns the result of calling `or`.
     *
     * @example
     * ```js
     * const slothActivities = [`sleeping`, `eating`, `climbing`]
     *
     * const iterator = Betterator.fromIterable(slothActivities)
     * for (let i = 0; i < 5; i++) {
     *   console.log(iterator.getNextOr(() => `No ${i + 1}th element!`))
     * }
     * //=> sleeping
     * //=> eating
     * //=> climbing
     * //=> No 4th element!
     * //=> No 5th element!
     * ```
     */
    getNextOr<Default>(or: () => Default): Value | Default;
    /**
     * Returns an {@link Betterator} constructed from the iterator returned by
     * `iterable`'s `Symbol.iterator` method.
     */
    static fromIterable<Value>(iterable: Iterable<Value>): Betterator<Value>;
}
/**
 * A wrapper around the native async iterator that provides a more ergonomic
 * API.
 *
 * @example
 * ```js
 * const slothActivities = (async function*() {
 *   yield* [`sleeping`, `eating`, `climbing`]
 * })()
 *
 * const asyncIterator = AsyncBetterator.fromAsyncIterable(slothActivities)
 * while (await asyncIterator.hasNext()) {
 *   console.log(await asyncIterator.getNext())
 * }
 * //=> sleeping
 * //=> eating
 * //=> climbing
 * ```
 */
declare class AsyncBetterator<Value> {
    /** Constructs an {@link AsyncBetterator} from `asyncIterator`. */
    constructor(asyncIterator: AsyncIterator<Value>);
    /**
     * Returns a promise that resolves to `true` if the underlying native async
     * iterator of this {@link AsyncBetterator} has been exhausted. Otherwise,
     * returns a promise that resolves to `false`.
     *
     * This method may call the underlying native async iterator's `next` method.
     */
    hasNext(): Promise<boolean>;
    /**
     * Returns a promise that resolves to the next element of the underlying
     * native async iterator.
     *
     * @throws if the underlying native async iterator does not have a next
     *   element.
     */
    getNext(): Promise<Value>;
    /**
     * Returns a promise that resolves to the next element of the underlying
     * native async iterator if it has a next element. Otherwise, it returns the
     * result of calling `or` as a promise.
     *
     * @example
     * ```js
     * const slothActivities = (async function*() {
     *   yield* [`sleeping`, `eating`, `climbing`]
     * })()
     *
     * const asyncIterator = AsyncBetterator.fromAsyncIterable(slothActivities)
     * for (let i = 0; i < 5; i++) {
     *   console.log(
     *     await asyncIterator.getNextOr(() => `No ${i + 1}th element!`)
     *   )
     * }
     * //=> sleeping
     * //=> eating
     * //=> climbing
     * //=> No 4th element!
     * //=> No 5th element!
     * ```
     */
    getNextOr<Default>(or: () => Default | PromiseLike<Default>): Promise<Value | Default>;
    /**
     * Returns an {@link AsyncBetterator} constructed from the async
     * iterator returned by `asyncIterable`'s `Symbol.asyncIterator` method.
     */
    static fromAsyncIterable<Value>(asyncIterable: AsyncIterable<Value>): AsyncBetterator<Value>;
}

export { AsyncBetterator, Betterator };