/**
 * astroengine scan -- long-scan ergonomics over the engine: a batched scan with
 * progress, and rankMoments to find the best instants by a score, synchronously
 * or without blocking the event loop.
 *
 * This is control flow over the validated primitives, not new ephemeris. The
 * score function is yours: compose it from positions, aspects, or the electional
 * state. scan imposes no scoring model. Because the core engine does no I/O,
 * these helpers (and the engine calls inside your score) run unchanged inside a
 * Web Worker; rankMomentsAsync additionally yields to the event loop so a
 * main-thread scan of hundreds of charts keeps the UI responsive.
 */
export interface ScanOptions {
    /** First instant, UT Julian Day (inclusive). */
    start: number;
    /** Last instant, UT Julian Day (inclusive). */
    end: number;
    /** Spacing between samples, days. Must be positive. */
    step: number;
    /** Called with (done, total) sample counts during the scan. */
    onProgress?: (done: number, total: number) => void;
    /** Samples between progress callbacks (default 256). */
    progressEvery?: number;
}
/** Number of samples a scan of these options visits. */
export declare function sampleCount(start: number, end: number, step: number): number;
/** Evaluate fn at each sampled instant in [start, end], returning the results in
 *  time order. */
export declare function scan<T>(opts: ScanOptions, fn: (jd: number) => T): T[];
export interface RankOptions extends ScanOptions {
    /** Keep only the top N moments (default: all). */
    limit?: number;
    /** Drop moments scoring below this (default: keep all). */
    minScore?: number;
}
export interface RankedMoment {
    jd: number;
    score: number;
}
/** Score every sampled instant and return the best, highest score first. */
export declare function rankMoments(opts: RankOptions, score: (jd: number) => number): RankedMoment[];
/** rankMoments that yields to the event loop every `chunk` samples, so a long
 *  main-thread scan does not freeze the UI. Same result as rankMoments. */
export declare function rankMomentsAsync(opts: RankOptions, score: (jd: number) => number, chunk?: number): Promise<RankedMoment[]>;