import { Ast } from 'thingtalk';
import * as C from '../ast_manip';
import { ContextInfo } from '../state_manip';
declare type EmptySearch = [Ast.Expression | null, C.ParamSlot | null, boolean];
/**
 * Agent dialogue act: a search command returned no result.
 *
 * @param ctx - the current context
 * @param base - the base table used in the reply
 * @param question - a search question used in the reply
 */
export declare function makeEmptySearchError(ctx: ContextInfo, [base, question, offerMonitor]: EmptySearch): import("../../sentence-generator/types").AgentReplyRecord | null;
/**
 * User dialogue act: in response to an empty search, the user changes their constraints.
 *
 * The "precise" variant explicitly contains a reference to a table, which must be the same
 * as the context.
 */
export declare function preciseEmptySearchChangeRequest(ctx: ContextInfo, phrase: Ast.Expression): Ast.DialogueState | null;
/**
 * User dialogue act: in response to an empty search, the user changes their constraints.
 *
 * The "imprecise" variant only contains a value and optionally a parameter name.
 * The table is inferred from the context.
 */
export declare function impreciseEmptySearchChangeRequest(ctx: ContextInfo, answer: Ast.Value | C.FilterSlot): Ast.DialogueState | null;
/**
 * User dialogue act: in response to an empty search where the agent proposed a statement,
 * the user accepts the statement.
 */
export declare function acceptEmptySearchOffer(ctx: ContextInfo): Ast.DialogueState | null;
export {};