static List expandOrClauses()

in spectator-api/src/main/java/com/netflix/spectator/impl/matcher/PatternUtils.java [223:257]

• 35 lines of code
• 14 McCabe index (conditional complexity)

  static List<Matcher> expandOrClauses(Matcher matcher, int max) {
    if (matcher instanceof IndexOfMatcher) {
      IndexOfMatcher m = matcher.as();
      return map(expandOrClauses(m.next(), max), n -> new IndexOfMatcher(m.pattern(), n), max);
    } else if (matcher instanceof ZeroOrMoreMatcher) {
      ZeroOrMoreMatcher m = matcher.as();
      return map(expandOrClauses(m.next(), max), n -> new ZeroOrMoreMatcher(m.repeated(), n), max);
    } else if (matcher instanceof ZeroOrOneMatcher) {
      ZeroOrOneMatcher m = matcher.as();
      List<Matcher> rs = expandOrClauses(m.repeated(), max);
      List<Matcher> ns = expandOrClauses(m.next(), max);
      if (rs == null || ns == null || ns.size() * (rs.size() + 1) > max) {
        return null;
      } else if (rs.size() == 1 && ns.size() == 1) {
        return Collections.singletonList(matcher);
      } else {
        List<Matcher> results = new ArrayList<>(ns);
        for (Matcher r : rs) {
          for (Matcher n : ns) {
            results.add(new ZeroOrOneMatcher(r, n));
          }
        }
        return results;
      }
    } else if (matcher instanceof PositiveLookaheadMatcher) {
      PositiveLookaheadMatcher m = matcher.as();
      return map(expandOrClauses(m.matcher(), max), PositiveLookaheadMatcher::new, max);
    } else if (matcher instanceof SeqMatcher) {
      return expandSeq(matcher.as(), max);
    } else if (matcher instanceof OrMatcher) {
      return expandOr(matcher.as(), max);
    } else {
      return Collections.singletonList(matcher);
    }
  }