import { LanguageTag, ValidationOptions, ValidationResult } from "../types/index.js";
/**
 * Validates a language tag against the BCP-47 specification
 *
 * @param tag The language tag to validate
 * @param options Validation options
 * @returns Validation result
 */
export declare function validateLanguageTag(tag: string, options?: ValidationOptions): ValidationResult;
/**
 * Checks if a language tag is well-formed according to BCP-47 syntax rules
 *
 * @param tag The language tag to check
 * @returns True if the tag is well-formed, false otherwise
 */
export declare function isWellFormed(tag: string): boolean;
/**
 * Checks if a language tag is valid (well-formed and all subtags exist in registry)
 *
 * @param tag The language tag to check
 * @returns True if the tag is valid, false otherwise
 */
export declare function isValid(tag: string): boolean;
/**
 * Parses a language tag string into its component parts without validation
 *
 * @param tag The language tag to parse
 * @returns The parsed language tag or null if parsing fails
 */
export declare function parseTag(tag: string): LanguageTag | null;
/**
 * Canonicalizes a language tag to its canonical form
 *
 * @param tag The language tag to canonicalize
 * @returns The canonicalized tag or null if the tag is invalid
 */
export declare function canonicalizeTag(tag: string): string | null;