import { type Dispatch, type SetStateAction } from "react";
import type { SortState } from "./sort_header";
/** `read` is required: stored data came from an earlier page version or by hand, so `JSON.parse` as `T` is
 *  a lie that surfaces as a filter matching nothing. Validate and return `undefined` to fall back. `write`
 *  only for types `JSON.stringify` cannot round-trip (`Set`, `Map`, `Date`). */
export interface PersistedCodec<T> {
    read: (raw: unknown) => T | undefined;
    write?: (value: T) => unknown;
}
/** `useState` that remembers what a reader arranged (filters, grouping, folded bands), with the same
 *  signature. Storage is per browser and origin — private to the app on that machine, never shared or
 *  synced — so it is for convenience only; durable facts belong in a record. Every access is guarded
 *  (absent, full, or throwing storage), and `fallback` makes the screen work with nothing stored. A new
 *  `key` (a viewer named once the host knows them) reads what that key holds. */
export declare function usePersistedState<T>(key: string, fallback: T, codec: PersistedCodec<T>): [T, Dispatch<SetStateAction<T>>];
/** A string from a known set (an option key, a grouping): an allowlist, since a deleted option's key would
 *  filter everything away. `""` is always allowed — the kit's "off". */
export declare function oneOf<T extends string>(allowed: readonly T[]): PersistedCodec<T | "">;
export declare const asText: PersistedCodec<string>;
/** Stored as an array, since JSON has no set; used for folded bands. */
export declare const asStringSet: PersistedCodec<Set<string>>;
/** Takes the sortable columns, so a stored key from a renamed or removed column falls back to the
 *  register's order. */
export declare function asSortState(keys: readonly string[]): PersistedCodec<SortState | null>;