import type { AccessChainElement } from "../types/access.js";
/**
 * Pure path-segment core, split out of `flow.ts` so both `flow.ts` and
 * `narrowing.ts` can VALUE-import it without forming a runtime cycle (`flow.ts`
 * value-imports `narrowByRefine` from `narrowing.ts`; `narrowing.ts` needs
 * `chainToSegments`). No dependency on the flow graph, scopes, or narrowing.
 */
/**
 * One hop of a narrowed access path. A `prop` is a static property name; an
 * `index` is a LITERAL array index. They are kept distinct so `box.r` (property
 * "r") and `arr[0]` (index 0) — and a numeric property `obj["0"]` vs `arr[0]` —
 * never alias in `referenceKey`/`isPrefixOf`. The chain is reserved for stable
 * paths only: calls, computed keys, slices, and method hops never appear here
 * (the recognizers reject them).
 */
export type PathSegment = {
    kind: "prop";
    name: string;
} | {
    kind: "index";
    index: number;
};
/**
 * A normalized reference path — the bound thing being narrowed. A bare variable
 * is the empty-chain case; member paths (`box.r`, `arr[0]`, `a.b.c`) carry their
 * hops as `PathSegment`s.
 */
export type Reference = {
    variable: string;
    chain: PathSegment[];
};
/** Stable string key for one path hop. `prop` → its name; `index` → `[N]`. */
export declare function segKey(seg: PathSegment): string;
/** Stable string key for a reference (map keys, equality). */
export declare function referenceKey(ref: Reference): string;
/**
 * True if `prefix` is a proper prefix of `path` (same variable; `prefix.chain`
 * is a leading sub-sequence of `path.chain`). Used for prefix invalidation:
 * reassigning `box` (or `box.r`) drops a narrowing on `box.r` (or `box.r.value`).
 */
export declare function isPrefixOf(prefix: Reference, path: Reference): boolean;
/**
 * One access-chain hop → a path segment, or null if the hop is UNSTABLE (a
 * computed/non-literal-integer index, a slice, or a method call). Stable hops:
 * a property, or a literal non-negative-integer index. THE single source of the
 * stability rule — `chainToSegments` and `stablePrefix` both build on it.
 */
export declare function toSegment(el: AccessChainElement): PathSegment | null;
/** Whole chain → segments, or null if ANY hop is unstable. */
export declare function chainToSegments(elements: AccessChainElement[]): PathSegment[] | null;
/**
 * The maximal STABLE prefix — stops at the first unstable hop instead of
 * nulling the whole chain. A later unstable hop must NOT block narrowing an
 * earlier stable prefix (`a.b[i()].x` can still use a narrowed `a.b`).
 */
export declare function stablePrefix(elements: AccessChainElement[]): PathSegment[];