Function surfaceByStem

src/context/approach-diff.ts:22–29

Map stem → first surface form, preserving first-seen order.

(text: string)

/** Map stem → first surface form, preserving first-seen order. */
function surfaceByStem(text: string): Map<string, string> {
  const m = new Map<string, string>();
  for (const w of tokenize(text)) {
    const s = stem(w);
    if (!m.has(s)) m.set(s, w);
  }
  return m;
}

/** Vocabulary diff of `other` against `ref`, compared by stem, displayed as surface words. PURE. */
export function termDiff(refText: string, otherText: string, cap = 8): TermDiff {