Method searchNodesFuzzy

src/db/queries.ts:930–984

* Fuzzy fallback: when zero FTS/LIKE hits, try an edit-distance * sweep over the distinct symbol-name set. Caps `maxDist` at 2 so * `getUssr` finds `getUser` but `process` doesn't match `prosody`. * Bounded edit distance keeps each comparison cheap; the per-query * scan is O(distinct-nam

(
    text: string,
    options: { kinds?: NodeKind[]; languages?: Language[]; limit: number }
  )

   * node count on any real codebase.
   */
  private searchNodesFuzzy(
    text: string,
    options: { kinds?: NodeKind[]; languages?: Language[]; limit: number }
  ): SearchResult[] {
    const { kinds, languages, limit } = options;
    const lowered = text.toLowerCase();
    const maxDist = lowered.length <= 4 ? 1 : 2;

    // Pull the distinct name list once. The set is cached on QueryBuilder
    // by getAllNodeNames(); even on a 200k-node project the distinct
    // name set is typically O(10k) because most names repeat. The
    // candidate-cap below bounds memory regardless.
    const allNames = this.getAllNodeNames();
    const candidates: Array<{ name: string; dist: number }> = [];
    for (const name of allNames) {
      const dist = boundedEditDistance(name.toLowerCase(), lowered, maxDist);
      if (dist <= maxDist) candidates.push({ name, dist });
    }
    candidates.sort((a, b) => a.dist - b.dist);

    // Cap the per-name follow-up queries. Each survivor triggers a
    // separate `SELECT * FROM nodes WHERE name = ?`; without this cap
    // a project with many similar names (`getUser1`, `getUser2`...)
    // could fan out far beyond `limit` queries before the inner-loop
    // limit kicks in.
    const FUZZY_FOLLOWUP_CAP = Math.max(limit * 2, 50);
    const cappedCandidates = candidates.slice(0, FUZZY_FOLLOWUP_CAP);

    const results: SearchResult[] = [];
    const seen = new Set<string>();
    for (const c of cappedCandidates) {
      if (results.length >= limit) break;
      let sql = 'SELECT * FROM nodes WHERE name = ?';
      const params: (string | number)[] = [c.name];
      if (kinds && kinds.length > 0) {
        sql += ` AND kind IN (${kinds.map(() => '?').join(',')})`;
        params.push(...kinds);
      }
      if (languages && languages.length > 0) {
        sql += ` AND language IN (${languages.map(() => '?').join(',')})`;
        params.push(...languages);
      }
      sql += ' LIMIT 5';
      const rows = this.db.prepare(sql).all(...params) as NodeRow[];
      for (const row of rows) {
        if (seen.has(row.id)) continue;
        seen.add(row.id);
        // Lower the score for each edit step away from the query so
        // exact-match fallbacks (dist 0) outrank dist-2 typos.
        results.push({ node: rowToNode(row), score: 1 / (1 + c.dist) });
        if (results.length >= limit) break;
      }
    }
    return results;
  }

  /**
   * FTS5 search with prefix matching