/**
 * A fixed-width digit mask: `99:99`, `99.99.9999`.
 *
 * Fixed means every character keeps its position. Clearing a digit in the middle leaves a hole
 * rather than pulling the rest left, which is what a date or a time wants: deleting the month
 * out of `11.11.2025` must not turn the year into the month.
 *
 * `9` marks a slot that takes a digit. Every other character is a literal the caret steps over
 * and the user cannot type into.
 */
export interface MaskSelection {
    start: number;
    end: number;
}
export interface MaskState {
    value: string;
    selection: MaskSelection | null;
}
/** The mask indices that take a digit, in order. */
export declare function slotIndices(mask: string): number[];
/** The mask with every slot empty: `__.__.____`. */
export declare function emptyMask(mask: string, placeholder: string): string;
/**
 * Any string as one character per mask index, so slots can be read and written by position.
 *
 * Every other function here assumes a value exactly as long as the mask, with literals where the
 * mask has them. Putting a value through this is what guarantees that, whether it came from a
 * keystroke, from a consumer's state, or from nothing at all.
 */
export declare function toMask(value: string, mask: string, placeholder: string): string;
/**
 * Where the caret belongs when the field is entered: the first slot with no digit in it.
 *
 * A mask is as wide when empty as when full, so a click lands wherever it likes, and clicking at
 * the end of `__.__.____` would otherwise leave the caret past every slot with nowhere to put the
 * next digit.
 */
export declare function firstEmptyCaret(value: string, mask: string, placeholder: string): number;
/**
 * What the field should show after the browser has changed its raw text, and where the caret
 * belongs.
 *
 * Works from the edit rather than from key events, so a paste, a drag, a replaced selection, an
 * autofill and a keystroke all arrive the same way.
 */
export declare function maskChange(previous: string, raw: string, caret: number, mask: string, placeholder: string): MaskState;
/** Whether a masked value holds no digits at all, so the field reads as empty. */
export declare function isBlank(value: string, mask: string): boolean;