// Создаём сегментатор слов с региональными настройками.
let segmenter = new Intl.Segmenter("fr", {granularity: "word"});
// Используем сегментатор для получения итератора по строке.
let input = "Moi?  N'est-ce pas.";
let segments = segmenter.segment(input);
// Используем итератор для сегментации!
for (let {segment, index, isWordLike} of segments) {
  console.log("segment at code units [%d, %d): «%s»%s",
    index, index + segment.length,
    segment,
    isWordLike ? " (word-like)" : ""
  );
}
// Вывод console.log:
// segment at code units [0, 3): «Moi» (word-like)
// segment at code units [3, 4): «?»
// segment at code units [4, 6): «  »
// segment at code units [6, 11): «N'est» (word-like)
// segment at code units [11, 12): «-»
// segment at code units [12, 14): «ce» (word-like)
// segment at code units [14, 15): « »
// segment at code units [15, 18): «pas» (word-like)
// segment at code units [18, 19): «.»

// ┃0 1 2 3 4 5┃6┃7┃8┃9
// ┃A l l o n s┃-┃y┃!┃
let input = "Allons-y!";
let segmenter = new Intl.Segmenter("fr", {granularity: "word"});
let segments = segmenter.segment(input);
let current = undefined;
current = segments.containing(0)
// → { index: 0, segment: "Allons", isWordLike: true }
current = segments.containing(5)
// → { index: 0, segment: "Allons", isWordLike: true }
current = segments.containing(6)
// → { index: 6, segment: "-", isWordLike: false }
current = segments.containing(current.index + current.segment.length)
// → { index: 7, segment: "y", isWordLike: true }
current = segments.containing(current.index + current.segment.length)
// → { index: 8, segment: "!", isWordLike: false }
current = segments.containing(current.index + current.segment.length)
// → undefined