/**
 * Visit item pairs while walking away from index 0 in both directions around a circular list.
 * The visitor receives `(previous, current)` pairs and may stop early by returning `true`.
 *
 * Order:
 * - Forward: 0 -> step -> 2*step -> ... -> middle (inclusive)
 * - Backward: 0 -> lastStep -> lastStep-step -> ... -> just above the middle
 *
 * @param items Items to walk.
 * @param step Step size for each hop.
 * @param visitPair Visitor called with `(previous, current)` pairs.
 * @returns `true` if the visitor stopped the walk.
 */
export declare function walkPairsOutward<T>(items: T[], step: number, visitPair: (previous: T, current: T) => boolean | void): boolean;