/**
 * Timestamp normalization + duration math. Pure and total — never throws,
 * never does I/O. All internal math is bigint ns (ADR D2 of the plan): no
 * float precision loss on unix-ns timestamps.
 */
import type { SpanStatus, TraceSpan } from "./types.js";
/**
 * Normalize a timestamp to unix ns. Accepts bigint ns, a numeric string
 * (treated as ns), or an ISO-8601 string (ms precision → ns). Returns null
 * for anything unparseable — callers treat null as "cannot place this span".
 */
export declare function toNs(value: bigint | string | null | undefined): bigint | null;
/** Span duration in ms; null when unavailable or clock-skewed (end < start). */
export declare function durationMs(span: Pick<TraceSpan, "startTime" | "endTime">): number | null;
/** Whether a span status counts as an error. Total: unknown statuses are not errors. */
export declare function isSpanError(status: SpanStatus | string | undefined): boolean;
/** Compact ms/s/min duration label (`1500 → "1.5s"`). Null → "in-flight". Pure, no locale. */
export declare function formatDurationMs(ms: number | null): string;