/**
 * The Level of Class Logger
 * Priority: ERROR > WARN > INFO > DEBUG
 *
 * @category Logger
 */
export declare enum Level {
    ERROR = 1,
    WARN = 2,
    INFO = 3,
    DEBUG = 4
}
/**
 * The options type of Class Logger
 *
 * @category Logger
 */
export interface Options {
    prefix?: string | undefined;
    onLog?: ((level: Level, args: Array<unknown>) => void) | undefined;
}
/**
 * Class Logger
 *
 * **Quick Usage:**
 * ```typescript
 * const logger = new Logger({ prefix: 'glacierjs' });
 * logger.info('hello');  // print: glacierjs [info] hello
 * logger.debug('hello');  // print: glacierjs [debug] hello
 * logger.warn('hello');  // print: glacierjs [warn] hello
 * logger.error('hello');  // print: glacierjs [error] hello
 * ```
 *
 * @category Logger
 */
export declare class Logger {
    static level: Level;
    private static methodToColorMap;
    private prefix;
    private onLog;
    constructor(options?: Options);
    error(...args: any[]): void;
    warn(...args: any[]): void;
    info(...args: any[]): void;
    debug(...args: any[]): void;
    extends({ prefix }: {
        prefix: Options['prefix'];
    }): Logger;
    private log;
    private getStyle;
}
/**
 * The instance of Class Logger in GlacierJS
 *
 * @category Logger
 */
export declare const logger: Logger;