/**
 * Namespace defining the `nil` attribute (used to represent `null` values).
 */
export declare const XSI_NS = "http://www.w3.org/2001/XMLSchema-instance";
/**
 * Namespace defining the `nil` attribute (used to represent `null` values).
 */
export declare const XSI_NS_PREFIX = "xsi";
/**
 * Transforms a map of namespaces into an object representing the attributes
 * used to declare the namespaces in the XML.
 * @param namespaces Record of namespaces (mapping from the namespace to its
 * prefix).
 * @returns Attributes to set in an XML element (mapping from attribute name to
 * its value).
 */
export declare function namespacesToAttributes(namespaces: Record<string, string>): Record<string, string>;
/**
 * Transforms an object representing the attributes of an XML element into a map
 * of namespaces.
 * @param attrs object representing the attributes of an XML element (mapping
 * from attribute name to its value).
 * @returns Map of namespaces (mapping from the namespace to its prefix).
 */
export declare function attributesToNamespaces(attrs: Record<string, string>): Record<string, string>;
/**
 * Adds a namespace to the record of namespaces if not yet added given a
 * preferred prefix for the namespace. If the prefix is already taken, a new one
 * is generated.
 * @param namespaces Map of namespaces (mapping from the namespace to its
 * prefix).
 * @param namespace Namespace to add.
 * @param preferredPrefix Preferred prefix to be associated with the namespace.
 */
export declare function addNamespace(namespaces: Record<string, string>, namespace: string, preferredPrefix: string): void;
/**
 * Returns the provided string with a namespace prefix.
 * @param namespaces Record of namespaces (mapping from the namespace to its
 * prefix).
 * @param ns Namespace to prefix.
 * @param str String to prefix with the namespace.
 * @returns Prefixed string.
 */
export declare function withPrefix(namespaces: Record<string, string>, ns: string, str: string): string;