/**
 * Format key characters that can appear in patterns
 */
export declare const FORMAT_KEY_CHARS: Set<string>;
/**
 * Represents a segment of the format string (mask field, separator, or literal)
 */
export interface FormatSegment {
    type: 'mask' | 'separator' | 'literal';
    text: string;
    start: number;
    end: number;
}
/**
 * Parse format string into segments with their actual value positions
 * Handles bracket literals and consecutive format keys
 */
export declare function parseFormatSegments(format: string): FormatSegment[];
/**
 * Check if a mask segment is fully filled with digits
 */
export declare function isMaskSegmentFilled(value: string, segment: FormatSegment): boolean;
/**
 * Find the last mask segment before a given position
 */
export declare function findPreviousMaskSegment(segments: FormatSegment[], currentPos: number): FormatSegment | null;
/**
 * Strip brackets from format string to get template without brackets
 */
export declare function getTemplateWithoutBrackets(format: string): string;
/**
 * Check if a character is a format key character
 */
export declare function isFormatKeyChar(char: string): boolean;