/**
 * One slug rule, three callers.
 *
 * Route segments, heading anchors and entity addresses all turn a human title
 * into an identifier, and they used to do it three different ways. The entity
 * slugger was ASCII-only, so every title in a non-Latin script came out
 * 'untitled' — a Russian site had one addressable entity and a duplicate-
 * address error for the rest, while its routes were fine, because those went
 * through a different function.
 */
/**
 * Slug for one route segment — same rules as page heading anchors.
 *
 * Accented letters are FOLDED to their base (ă → a, ș → s, ł → l), not dropped:
 * filtering to ASCII first would turn "Verificări" into "verificri" and
 * "Setări" into "setri" — URLs that read like typos in every language that
 * isn't English. NFD splits a letter into base + combining mark, so removing
 * the marks leaves the base behind.
 *
 * Scripts with no ASCII base — Greek, Cyrillic, CJK, Arabic — keep their own
 * letters. They used to be stripped, which left every such title slugged
 * 'item': a site written in Russian had one reachable page and a route
 * collision for the rest. The router percent-encodes on the way out and
 * decodes on the way in, so `/кнопка` addresses the page it names.
 */
export declare function slugifySegment(text: string, fallback?: string): string;
/**
 * Decompose, then drop the combining marks — "ă" becomes "a".
 *
 * NFD only helps where the mark is a SEPARATE combining character. Letters whose
 * diacritic is part of the glyph have no canonical decomposition — a stroke is not a
 * combining mark — so ł, đ, ø and friends survive NFD untouched and would then be
 * filtered away. They get an explicit map; the list is the Latin-script letters a
 * European or Vietnamese title realistically contains.
 *
 * The fold applies only where it lands on the Latin alphabet. Outside it, a
 * combining mark is not an accent on a letter you already have: strip the
 * dakuten from ボ and you get ホ — "bo" becomes "ho", a different word.
 */
export declare function foldAccents(text: string): string;