import type { FilterFieldProps } from '../../FilterField.types.js';
import type { FilterFieldValueOperationResult, FilterFieldValueOperationStatement } from '../../types/value-operations.js';
/**
 * Adds a filter statement or value to an existing FilterField value string.
 *
 * - If no statement with the given key exists, a new one is appended at the end.
 * - If a matching `key = value` statement exists, it is converted to `key in (existingValue, newValue)`.
 * - If a matching `key in (...)` statement exists, the new value is appended to the list.
 * - The same merge logic applies to `!=` / `not in`.
 * - When multiple statements with the same key exist, the rightmost one (in document order) wins.
 *
 * @public
 * @param currentValue - The current FilterField value string.
 * @param filter - The filter statement or value to add.
 * @param options - Optional configuration. `parserConfig` controls how `currentValue` is parsed
 *                  and which leaf types are constructed for new keys / values.
 * @returns The new FilterField value string and whether the operation produced a change.
 */
export declare function addFilter(currentValue: string, filter: FilterFieldValueOperationStatement, options?: {
    /** Parser config to apply when interpreting the existing value and constructing new nodes. */
    parserConfig?: FilterFieldProps['parserConfig'];
}): FilterFieldValueOperationResult;