private function getUnusedClauses()

in src/Linters/UnusedUseClauseLinter.hack [42:97]
52 lines of code
13 McCabe index (conditional complexity)

  private function getUnusedClauses(
    ?Token $kind,
    vec<NamespaceUseClause> $clauses,
  ): vec<(string, NamespaceUseClause)> {
    $used = $this->getUnresolvedReferencedNames();
    $unused = vec[];
    foreach ($clauses as $clause) {
      $as = $clause->getAlias();
      if ($as !== null) {
        $as = $as->getText();
      } else {
        $name = $clause->getName();
        if ($name is NameToken) {
          $as = $name->getText();
        } else {
          invariant($name is QualifiedName, 'Unhandled name type');
          $as = $name->getParts()->getChildrenOfItemsOfType(NameToken::class)
            |> (C\lastx($$) as nonnull)->getText();
        }
      }
      if ($kind is NamespaceToken) {
        if (!C\contains($used['namespaces'], $as)) {
          $unused[] = tuple($as, $clause);
        }
        continue;
      }
      if ($kind is TypeToken) {
        if (!C\contains($used['types'], $as)) {
          $unused[] = tuple($as, $clause);
        }
        continue;
      }

      if ($kind is FunctionToken) {
        if (!C\contains($used['functions'], $as)) {
          $unused[] = tuple($as, $clause);
        }
        continue;
      }

      if ($kind is ConstToken) {
        // unsupported
        continue;
      }

      invariant($kind === null, 'Unhandled kind: %s', \get_class($kind));
      if (C\contains($used['namespaces'], $as)) {
        continue;
      }
      if (C\contains($used['types'], $as)) {
        continue;
      }
      $unused[] = tuple($as, $clause);
    }
    return $unused;
  }