export declare const SURVEY_FIELD_EMAIL_VALIDATION_DELAY_MS = 1500;
export declare const INVALID_EMAIL_MESSAGE = "Please enter a valid email address";
type ErrorChangeHandler = (fieldKey: string, error: string | null) => void;
export declare function isValidEmailAddress(email: string): boolean;
/**
 * Debounces visible respondent email feedback independently for each field.
 * Required-field validity remains the responsibility of the component's
 * synchronous submit-button validation.
 */
export declare class SurveyFieldEmailValidation {
    private readonly onErrorChange;
    private readonly timers;
    constructor(onErrorChange: ErrorChangeHandler);
    validate(fieldKey: string, value: string): void;
    clearField(fieldKey: string): void;
    clearAll(): void;
    private cancel;
}
export {};