export declare const enum PATCH_OP_TYPE {
    DEL = -1,
    EQL = 0,
    INS = 1
}
export type Patch = PatchOperation[];
export type PatchOperation = PatchOperationDelete | PatchOperationEqual | PatchOperationInsert;
export type PatchOperationDelete = [type: PATCH_OP_TYPE.DEL, txt: string];
export type PatchOperationEqual = [type: PATCH_OP_TYPE.EQL, txt: string];
export type PatchOperationInsert = [type: PATCH_OP_TYPE.INS, txt: string];
/**
 * Determine the common prefix of two strings.
 *
 * @param txt1 First string.
 * @param txt2 Second string.
 * @return The number of characters common to the start of each string.
 */
export declare const pfx: (txt1: string, txt2: string) => number;
/**
 * Determine the common suffix of two strings.
 *
 * @param txt1 First string.
 * @param txt2 Second string.
 * @return The number of characters common to the end of each string.
 */
export declare const sfx: (txt1: string, txt2: string) => number;
/**
 * Find the differences between two texts.
 *
 * @param src Old string to be diffed.
 * @param dst New string to be diffed.
 * @return A {@link Patch} - an array of patch operations.
 */
export declare const diff: (src: string, dst: string) => Patch;
/**
 * Considers simple insertion and deletion cases around the caret position in
 * the destination string. If the fast patch cannot be constructed, it falls
 * back to the default full implementation.
 *
 * Cases considered:
 *
 * 1. Insertion of a single or multiple characters right before the caret.
 * 2. Deletion of one or more characters right before the caret.
 *
 * @param src Old string to be diffed.
 * @param dst New string to be diffed.
 * @param caret The position of the caret in the new string. Set to -1 to
 *     ignore the caret position.
 * @return A {@link Patch} - an array of patch operations.
 */
export declare const diffEdit: (src: string, dst: string, caret: number) => Patch;
export declare const src: (patch: Patch) => string;
export declare const dst: (patch: Patch) => string;
/**
 * Inverts patch such that it can be applied to `dst` to get `src` (instead of
 * `src` to get `dst`).
 *
 * @param patch The patch to invert.
 * @returns Inverted patch.
 */
export declare const invert: (patch: Patch) => Patch;
/**
 * @param patch The patch to apply.
 * @param srcLen The length of the source string.
 * @param onInsert Callback for insert operations.
 * @param onDelete Callback for delete operations.
 */
export declare const apply: (patch: Patch, srcLen: number, onInsert: (pos: number, str: string) => void, onDelete: (pos: number, len: number, str: string) => void) => void;