import type { ExistsResult, ExistsOptions } from './npm.js';
interface PurlObject {
    name: string;
    namespace?: string | undefined;
    qualifiers?: Record<string, string> | undefined;
    subpath?: string | undefined;
    type?: string | undefined;
    version?: string | undefined;
}
/**
 * Check if an R package exists on CRAN.
 *
 * Queries CRAN database to verify package existence and retrieve
 * the latest version. Note: CRAN provides a list of all packages
 * via their packages.rds file.
 *
 * @param name - Package name (e.g., 'ggplot2')
 * @param version - Optional version to validate (e.g., '3.4.4')
 * @param options - Optional configuration including cache
 * @returns Promise resolving to existence result with latest version
 *
 * @example
 * ```typescript
 * // Check if package exists
 * const result = await cranExists('ggplot2')
 * // -> { exists: true, latestVersion: '3.4.4' }
 *
 * // Validate specific version
 * const result = await cranExists('ggplot2', '3.4.4')
 * // -> { exists: true, latestVersion: '3.4.4' }
 *
 * // Non-existent package
 * const result = await cranExists('FakePackage')
 * // -> { exists: false, error: 'Package not found' }
 * ```
 */
export declare function cranExists(name: string, version?: string, options?: ExistsOptions): Promise<ExistsResult>;
/**
 * Validate CRAN package URL.
 * CRAN packages require a version. Name must not contain injection characters.
 */
export declare function validate(purl: PurlObject, throws: boolean): boolean;
export {};