import java.util.stream.IntStream;
import org.jspecify.annotations.Nullable;

/** Spliterator utilities for {@code common.collect} internals. */
@GwtCompatible
final class CollectSpliterators {
  private CollectSpliterators() {}

  static <T extends @Nullable Object> Spliterator<T> indexed(
      int size, int extraCharacteristics, IntFunction<T> function) {
    return indexed(size, extraCharacteristics, function, null);

import junit.framework.TestCase;
import org.jspecify.annotations.NullMarked;

/** Tests for {@code CollectSpliterators}. */
@GwtCompatible
@NullMarked
public class CollectSpliteratorsTest extends TestCase {
  @GwtIncompatible
  public void testMap() {
    SpliteratorTester.of(
            () ->
                CollectSpliterators.map(
                    Arrays.spliterator(new String[] {"a", "b", "c", "d", "e"}),
                    0,

          return getEntry(index);
        }
      };
    }

    @Override
    @GwtIncompatible // Spliterator
    Spliterator<Entry<K, V>> entrySpliterator() {
      return CollectSpliterators.indexed(
          size(), Spliterator.ORDERED | Spliterator.DISTINCT | Spliterator.NONNULL, this::getEntry);
    }

    // TODO(lowasser): consider an optimized values() implementation

    @Override

      @Override
      public V next() {
        return entryItr.next().getValue();
      }
    };
  }

  @Override
  @GwtIncompatible // Spliterator
  public Spliterator<V> spliterator() {
    return CollectSpliterators.map(
        map.entrySet().spliterator(),
        Spliterator.ORDERED | Spliterator.IMMUTABLE | Spliterator.NONNULL,
        Entry::getValue);
  }

  @Override

      characteristics &= splitr.characteristics();
      estimatedSize = LongMath.saturatedAdd(estimatedSize, splitr.estimateSize());
    }
    return StreamSupport.stream(
            CollectSpliterators.flatMap(
                splitrsBuilder.build().spliterator(),
                splitr -> (Spliterator<T>) splitr,
                characteristics,
                estimatedSize),
            isParallel)

    return Maps.unmodifiableEntryIterator(delegate.entrySet().iterator());
  }

  @Override
  @GwtIncompatible // Spliterator
  Spliterator<Entry<K, V>> entrySpliterator() {
    return CollectSpliterators.map(
        delegate.entrySet().spliterator(),
        Spliterator.DISTINCT | Spliterator.ORDERED | Spliterator.IMMUTABLE | Spliterator.NONNULL,
        Maps::unmodifiableEntry);
  }

  @Override

  @Override
  Spliterator<Entry<K, V>> entrySpliterator() {
    return CollectSpliterators.flatMap(
        map.entrySet().spliterator(),
        keyToValueCollectionEntry -> {
          K key = keyToValueCollectionEntry.getKey();
          Collection<V> valueCollection = keyToValueCollectionEntry.getValue();
          return CollectSpliterators.map(
              valueCollection.spliterator(),

      }
    }
  }

  @Override
  @GwtIncompatible // Spliterator
  Spliterator<Cell<R, C, V>> cellSpliterator() {
    return CollectSpliterators.flatMap(
        backingMap.entrySet().spliterator(),
        (Entry<R, Map<C, V>> rowEntry) ->
            CollectSpliterators.map(
                rowEntry.getValue().entrySet().spliterator(),
                0,
                (Entry<C, V> columnEntry) ->

      V transform(Cell<R, C, V> cell) {
        return cell.getValue();
      }
    };
  }

  @GwtIncompatible // Spliterator
  Spliterator<V> valuesSpliterator() {
    return CollectSpliterators.map(cellSpliterator(), 0, Table.Cell::getValue);
  }

  @WeakOuter
  private final class Values extends AbstractCollection<V> {
    @Override
    public Iterator<V> iterator() {

      characteristics &= splitr.characteristics();
      estimatedSize = LongMath.saturatedAdd(estimatedSize, splitr.estimateSize());
    }
    return StreamSupport.stream(
            CollectSpliterators.flatMap(
                splitrsBuilder.build().spliterator(),
                splitr -> (Spliterator<T>) splitr,
                characteristics,
                estimatedSize),
            isParallel)