/**
 * Parse / serialize SpreadsheetML rich-text runs (`CT_RElt` / `CT_RPrElt`).
 *
 * Citations:
 * - ECMA-376-1 §18.4 Shared String Table
 * - Transitional `sml.xsd`: `CT_Rst`, `CT_RElt`, `CT_RPrElt`
 * - Path: `specs/schemas/xsd/OfficeOpenXML-XMLSchema-Transitional/sml.xsd`
 *
 * Run typeface uses `rFont` (not styles-table `font/name`).
 *
 * @private
 */
import { Font as FontInput } from '../styles/styles-xml';
/**
 * One rich-text run: text plus optional run properties.
 */
export interface RichTextRun {
    readonly text: string;
    readonly font?: FontInput;
}
/**
 * Join run texts into the plain fallback string.
 */
export declare function joinRunText(runs: ReadonlyArray<RichTextRun>): string;
/**
 * True when any run carries explicit font properties.
 */
export declare function runsHaveFont(runs: ReadonlyArray<RichTextRun>): boolean;
/**
 * Snapshot `FontInput` (strip undefined; deep-copy color).
 */
export declare function snapshotFontInput(input: FontInput | undefined): FontInput | undefined;
/**
 * Canonical key for coalescing adjacent runs with equal fonts.
 */
export declare function fontInputMatchKey(font: FontInput | undefined): string;
/**
 * Coalesce adjacent runs that share the same font key.
 */
export declare function coalesceRuns(runs: ReadonlyArray<RichTextRun>): RichTextRun[];
/**
 * Expand runs to per-code-unit fonts, assign inclusive range, coalesce.
 */
export declare function applyFontToRange(runs: ReadonlyArray<RichTextRun>, start: number, end: number, font: FontInput | undefined): RichTextRun[];
/**
 * Parse runs from a full `<si>…</si>` or `<is>…</is>` element, or inner XML.
 * Phonetic (`rPh` / `phoneticPr`) and unknown children are skipped on rebuild.
 */
export declare function parseRichRunsFromSiXml(siOrInnerXml: string): RichTextRun[];
/**
 * Serialize runs to a full `<si>…</si>` element (`CT_Rst` with `r*` only).
 */
export declare function serializeRichSiXml(runs: ReadonlyArray<RichTextRun>): string;
/**
 * Parse `CT_RPrElt` (`rPr`).
 */
export declare function parseRPrElement(rPrXml: string): FontInput;
/**
 * Serialize `CT_RPrElt` with `rFont` for typeface.
 */
export declare function serializeRPrElement(font: FontInput): string;