type EditRangeResult<V, R = number> = {
    value?: V;
    break?: R;
    delete?: boolean;
};
/**
 * Mutable B+ tree used by BTreeIndex for sorted value buckets. Keys use the
 * supplied comparator; point operations cost O(log size). This local fork has
 * no copy-on-write sharing, cloning, or optional-value storage.
 * Range callbacks may return { break: result } to stop traversal early.
 * @author David Piepgrass
 */
export declare class BTree<K = any, V = any> {
    private _root;
    _size: number;
    _maxNodeSize: number;
    /**
     * provides a total order over keys (and a strict partial order over the type K)
     * @returns a negative value if a < b, 0 if a === b and a positive value if a > b
     */
    _compare: (a: K, b: K) => number;
    /**
     * Initializes an empty B+ tree.
     * @param compare Custom function to compare pairs of elements in the tree.
     * @param maxNodeSize Branching factor (maximum items or children per node)
     *   Must be in range 4..256. If undefined or <4 then default is used; if >256 then 256.
     */
    constructor(compare: (a: K, b: K) => number, maxNodeSize?: number);
    /** Gets the number of key-value pairs in the tree. */
    get size(): number;
    /** Releases the tree so that its size is 0. */
    clear(): void;
    /**
     * Finds a pair in the tree and returns the associated value.
     * @param defaultValue a value to return if the key was not found.
     * @returns the value, or defaultValue if the key was not found.
     * @description Computational complexity: O(log size)
     */
    get(key: K, defaultValue?: V): V | undefined;
    /**
     * Adds or overwrites a key-value pair in the B+ tree.
     * @param key the key is used to determine the sort order of
     *        data in the tree.
     * @param value data to associate with the key
     * @param overwrite Whether to overwrite an existing key-value pair
     *        (default: true). If this is false and there is an existing
     *        key-value pair then this method has no effect.
     * @returns true if a new key-value pair was added.
     * @description Computational complexity: O(log size)
     * Note: when overwriting a previous entry, the key is updated
     * as well as the value. This has no effect unless the new key
     * has data that does not affect its sort order.
     */
    set(key: K, value: V, overwrite?: boolean): boolean;
    /**
     * Returns true if the key exists in the B+ tree, false if not.
     * Use get() for best performance; use has() if you need to
     * distinguish between "undefined value" and "key not present".
     * @param key Key to detect
     * @description Computational complexity: O(log size)
     */
    has(key: K): boolean;
    /**
     * Removes a single key-value pair from the B+ tree.
     * @param key Key to find
     * @returns true if a pair was found and removed, false otherwise.
     * @description Computational complexity: O(log size)
     */
    delete(key: K): boolean;
    /** Gets the lowest key in the tree. Complexity: O(log size) */
    minKey(): K | undefined;
    /** Gets the highest key in the tree. Complexity: O(1) */
    maxKey(): K | undefined;
    /** Returns the next pair whose key is larger than the specified key (or undefined if there is none).
     * If key === undefined, this function returns the lowest pair.
     * @param key The key to search for.
     * @param reusedArray Optional array used repeatedly to store key-value pairs, to
     * avoid creating a new array on every iteration.
     */
    nextHigherPair(key: K | undefined, reusedArray?: [K, V]): [K, V] | undefined;
    /** Returns the next pair whose key is smaller than the specified key (or undefined if there is none).
     *  If key === undefined, this function returns the highest pair.
     * @param key The key to search for.
     * @param reusedArray Optional array used repeatedly to store key-value pairs, to
     *        avoid creating a new array each time you call this method.
     */
    nextLowerPair(key: K | undefined, reusedArray?: [K, V]): [K, V] | undefined;
    forRange(low: K, high: K, includeHigh: boolean, onFound?: (k: K, v: V, counter: number) => void, initialCounter?: number): number;
    /**
     * Scans and potentially modifies values for a subsequence of keys.
     * Note: the callback `onFound` should ideally be a pure function.
     *   Specfically, it must not insert items or change the collection
     *   except via return value; out-of-band editing may cause an
     *   exception or may cause incorrect data to be sent to the callback
     *   (duplicate or missed items).
     * @param low The first key scanned will be greater than or equal to `low`.
     * @param high Scanning stops when a key larger than this is reached.
     * @param includeHigh If the `high` key is present, `onFound` is called for
     *        that final pair if and only if this parameter is true.
     * @param onFound A function that is called for each key-value pair. This
     *        function can return `{value:v}` to change the value associated
     *        with the current key, `{delete:true}` to delete the current pair,
     *        `{break:R}` to stop early with result R, or it can return nothing
     *        (undefined or {}) to cause no effect and continue iterating.
     *        `{break:R}` can be combined with one of the other two commands.
     *        The third argument `counter` is the number of items iterated
     *        previously; it equals 0 when `onFound` is called the first time.
     * @returns The number of values scanned, or R if the callback returned
     *        `{break:R}` to stop early.
     * @description
     *   Computational complexity: O(number of items scanned + log size)
     */
    editRange<R = V>(low: K, high: K, includeHigh: boolean, onFound: (k: K, v: V, counter: number) => EditRangeResult<V, R> | void, initialCounter?: number): R | number;
}
export {};