/**
 * Wrapper around `pgsql-parser` that handles the reality that RLS predicates
 * appearing in `pg_get_expr(polqual, polrelid)` are fragments, not statements.
 *
 * We wrap the fragment in a `SELECT … WHERE <expr>` so the parser accepts it,
 * then pull the `whereClause` out of the resulting AST.
 */
/** Opaque AST node — intentionally `unknown` to keep us loose against pgsql-parser upgrades. */
export type PgAstNode = unknown;
export interface PolicyExpression {
    /** Original text (exactly as returned by pg_get_expr). */
    text: string;
    /** Root AST node of the expression (not the wrapping SELECT). */
    ast: PgAstNode;
}
export declare class PolicyParseError extends Error {
    readonly expr: string;
    readonly cause: unknown;
    constructor(expr: string, cause: unknown);
}
/**
 * Parse a policy expression fragment.
 *
 * `parse` from pgsql-parser v17 is async (it awaits a WASM load), so this
 * wrapper is async too.
 *
 * @param expr   The text from `pg_get_expr(...)`.
 * @returns      Parsed AST, or `null` if `expr` is null/empty.
 * @throws       `PolicyParseError` on parse failure.
 */
export declare function parsePolicyExpression(expr: string | null): Promise<PolicyExpression | null>;