import type { ExpressionErrorReason } from "@uicast/expr";
/**
 * What failed: an expression's refusal or failure (an `ExpressionErrorReason`), or an element-level one.
 *
 * @example
 * if (error.reason === "unknown-component") return <p>No implementation for {error.elementKey}</p>;
 */
export type EntryErrorReason = ExpressionErrorReason | "invalid-entry" | "unknown-component" | "invalid-list" | "invalid-props" | "host-init" | "implementation" | "unknown";
/**
 * Whose code must fix a failure: `"document"` the model's (re-emit the entry), `"environment"` the host's, `"unknown"`
 * either.
 *
 * @example
 * const fault: EntryFault = error.fault; // "document" for reason "invalid-props"
 */
export type EntryFault = "document" | "environment" | "unknown";
export declare const FAULT_BY_REASON: Record<EntryErrorReason, EntryFault>;
export declare const REASON_DESCRIPTIONS: Record<EntryErrorReason, string>;
/**
 * The classified error every element failure arrives as, in the error slot and in `onError`. `reason` says what
 * failed; `fault` says whose code must fix it.
 *
 * @example
 * const onError = (error: EntryError) =>
 *   error.fault === "document" ? askModelToFix(error.elementKey, error.message) : report(error);
 */
export declare class EntryError extends Error {
    /** What failed, e.g. `"invalid-props"`. */
    readonly reason: EntryErrorReason;
    /** The key of the element that failed. The error boundary fills it in when the throw site could not. */
    elementKey?: string;
    /** Brand for `EntryError.is`: `instanceof` fails when two copies of this package share a bundle. */
    readonly uicastEntryError = true;
    constructor(message: string, options: {
        reason: EntryErrorReason;
        elementKey?: string;
        cause?: unknown;
    });
    /** Whose code must fix it: `"document"` (the model, by re-emitting), `"environment"` (host code) or `"unknown"`. */
    get fault(): EntryFault;
    /**
     * Whether `err` is an `EntryError`, from any copy of this package. Use it over `instanceof`.
     *
     * @example
     * if (EntryError.is(err)) console.warn(err.reason, err.elementKey);
     */
    static is(err: unknown): err is EntryError;
    /**
     * Turns any thrown value into an `EntryError` with this `reason`. An `EntryError` passes through as is, and gets
     * `elementKey` if it had none.
     *
     * @example
     * const error = EntryError.wrap(err, "implementation", "orders-table");
     * error.fault; // "environment"
     */
    static wrap(err: unknown, reason: EntryErrorReason, elementKey?: string): EntryError;
}