import { Env } from "../env";
import { Goal, GoalQueue } from "../goal";
import { Mod } from "../mod";
import { Solution } from "../solution";
/**

   # Solver

   In implementation, we use array of queues to do search,
   but we should be thinking in terms of tree instead of queues,
   only by doing so, we can have a clear understanding of the implementation.

**/
export declare class Solver<T> {
    queues: Array<GoalQueue>;
    constructor(queues: Array<GoalQueue>);
    static forGoals<T>(goals: Array<Goal>): Solver<T>;
    next(mod: Mod, env: Env): Solution | undefined;
    report(): void;
    solve(mod: Mod, env: Env, options?: {
        limit?: number;
    }): Array<Solution>;
}
export declare function formatGoal(goal: Goal): string;