/**
 * Minimal XML helpers for OPC content types and relationships.
 *
 * Intentionally small: attribute-oriented element extraction without a full DOM.
 * Not a general-purpose OOXML parser — higher layers will own SpreadsheetML.
 *
 * @private
 */
/**
 * Decode UTF-8 (with BOM strip) package part text.
 */
export declare function decodeUtf8(bytes: Uint8Array): string;
/**
 * Encode text as UTF-8 bytes.
 */
export declare function encodeUtf8(text: string): Uint8Array;
/**
 * Escape attribute values for XML 1.0 (double-quoted attributes).
 */
export declare function escapeXml(value: string): string;
/**
 * Escape character data (element text). Does not escape quotes — Excel formula
 * text (`f`) and similar keep literal `"` as in the original package.
 */
export declare function escapeXmlText(value: string): string;
/**
 * Unescape common XML attribute / text entities.
 */
export declare function unescapeXml(value: string): string;
/**
 * Parse attribute text into a map. Prefixed names are stored under the full
 * name and also under the local name when that slot is free so callers can
 * look up either form. Local aliases must not be re-emitted on serialize
 * (see {@link attrsToXmlExcluding}).
 */
export declare function parseAttrMap(attrText: string): Map<string, string>;
/**
 * Serialize attributes, skipping exclude keys and parseAttrMap local aliases.
 *
 * - Keeps `xmlns:*` declarations (only the exact exclude set drops them).
 * - Drops unprefixed aliases synthesized for `prefix:local` / `xmlns:prefix`.
 * - Exclusion matches exact key, or local name for non-namespace attrs
 *   (so `exclude {'id'}` drops both `id` and `r:id`).
 */
export declare function attrsToXmlExcluding(attrs: Map<string, string>, exclude: Set<string>): string;
/**
 * One empty-or-simple XML element with attributes (body ignored for OPC CT/rels).
 */
export interface XmlElementAttrs {
    readonly localName: string;
    readonly attrs: ReadonlyMap<string, string>;
}
/**
 * Extract elements by local name with their attributes.
 * Handles default and prefixed tags; ignores comments and processing instructions.
 */
export declare function findElementsWithAttrs(xml: string, localName: string): XmlElementAttrs[];
/**
 * Require a root local name to appear (namespace prefix optional).
 */
export declare function assertRootLocalName(xml: string, localName: string, partName: string): void;