/**
 * Words of a joining script (Arabic, Syriac, N'Ko, Mongolian, Adlam…) stay
 * whole: their letters connect, and the shape of each letter depends on
 * its neighbours. A piece of such a word measured alone has the wrong
 * width (in Amiri `مكت` alone is wider than the whole `مكتبة`), and painted
 * alone it shows the wrong letter forms. So the measurer never hyphenates
 * one, never cuts one between letters, never measures a prefix of one, and
 * never spreads letter-spacing on one (tracking breaks the joins on every
 * renderer, as CSS `letter-spacing` does). See engine-ltr-audit §1.3–1.4
 * and §2.2.
 *
 * The predicates here are the measurer's gate: they cost one comparison
 * per UTF-16 unit for text with nothing past U+05FF (every Latin, Greek,
 * Cyrillic, Hebrew or CJK word), which never holds a joining letter.
 */
/** Whether `text` holds a letter of a joining script (dual-, right- or
 *  left-joining, see `hasJoiningScript`): a word to keep whole and set
 *  without tracking. */
export declare function joiningScriptIn(text: string): boolean;
/**
 * Whether a cut before `text[idx]` falls inside a word of a joining script:
 * between two of its letters (whether or not those two connect: an Arabic
 * word is not divided at a line end either way), or before a mark, which
 * stays with its letter. A cut between an Arabic word and a Latin one or a
 * digit run glued to it (`ABCكتاب`, `و2020`) is not inside one.
 */
export declare function insideJoiningWord(text: string, idx: number): boolean;
/**
 * Whether most of a paragraph's letters belong to a joining script: an
 * Arabic paragraph, which no tracking lever may reach (column balancing's
 * paragraph tracking, the runt fix's negative tracking). Those levers then
 * fall through to the others. A Latin paragraph quoting an Arabic word
 * keeps them: the quoted word alone is set without tracking.
 */
export declare function mostlyJoiningScript(text: string): boolean;
/** The tracking (letter-spacing) a word of `text` takes, `letterSpacingPx`
 *  after each grapheme: none on a word of a joining script. */
export declare function wordLetterSpacing(text: string, letterSpacingPx: number): number;
//# sourceMappingURL=joining.d.ts.map