import { SyslConfiguration } from "../config";
import { Sysl } from "./sysl";
/** The minimum supported version of the Sysl binary. */
export declare const minVersion = "0.791.0";
/** The minimum supported version of the Sysl binary as a semantic version. */
export declare const minSemver: import("semver").SemVer;
export declare class SyslDownloader {
    private readonly config?;
    constructor(config?: SyslConfiguration | undefined);
    /**
     * Returns an instance of {@link Sysl} to perform Sysl operations (e.g. parsing).
     *
     * Looks for Sysl on the process environment's path and in {@link dir}. If an executable is not
     * found, the latest version of Sysl will be downloaded into {@link dir}.
     */
    getOrDownloadSysl(dir: string): Promise<Sysl>;
    /**
     * Returns a local instance of {@link Sysl} to perform Sysl operations (e.g. parsing).
     *
     * If no local copy of Sysl could be found, the promise will be rejected. Use
     * {@link getOrDownloadSysl} to also fetch a copy of Sysl if it's missing locally.
     *
     * @param dir Directory to check in addition and in precedence to the system path.
     */
    localSysl(dir: string): Promise<Sysl>;
    /**
     * Attempts to invoke Sysl at the given path to check its existence.
     * Returns a {@link Sysl} instance if it can be invoked.
     */
    checkSysl(syslPath: string): Promise<Sysl>;
    /** Downloads Sysl from https://github.com/anz-bank/sysl/releases. */
    downloadSysl(dir: string): Promise<Sysl>;
}
/** Error messages relating to Sysl downloading and availability. */
export declare const errorMessage: {
    syslUnavailable: string;
};