export declare class State {
    private _failure;
    private rootState;
    private readonly _depth;
    private _emits;
    private success;
    constructor(depth: number);
    get failure(): State | null;
    set failure(state: State | null);
    get depth(): number;
    get emits(): string[];
    /**
     * Add outputs to the state.
     *
     * @param keywords the list of outputs.
     */
    addEmits(keywords: string[]): void;
    /**
     * Transit to the next state with the given character.
     *
     * @param char input character for the transition.
     */
    nextState(char: string, ignoreRootState?: boolean): State | null;
    /**
     * Create a new state and add a transition to the new state
     * with the given character.
     *
     * @param char input character for moving to the new state.
     */
    addState(char: string): State;
    /**
     * Return the list of reachable states with one step.
     */
    getStates(): State[];
    /**
     * Get the possible char to move to the next state.
     */
    getTransitions(): string[];
}