import { State } from "../vm";
import { MappedRelation, Predicate } from "./predicate";
import { UnificationEnvironment } from "./unification";
export declare class Database implements IDatabase {
    private relations;
    add(name: string, relation: MappedRelation): void;
    update(name: string, relation: MappedRelation): void;
    try_lookup(name: string): MappedRelation | null;
    lookup(name: string): MappedRelation;
    search(state: State, predicate: Predicate, initial_environment: UnificationEnvironment): UnificationEnvironment[];
}
export interface IDatabase {
    add(name: string, relation: MappedRelation): void;
    update(name: string, relation: MappedRelation): void;
    lookup(name: string): MappedRelation;
    try_lookup(name: string): MappedRelation | null;
    search(state: State, predicate: Predicate, initial_environment: UnificationEnvironment): UnificationEnvironment[];
}