code: /*
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
   * compliance with the License. You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software distributed under the License is
   * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
   * the License for the specific language governing permissions and limitations under the License.
   */
  
  package io.reactivex.rxjava3.internal.operators.flowable;
  
  import java.util.Iterator;
  import java.util.Objects;
  
  import org.reactivestreams.*;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.exceptions.Exceptions;
  import io.reactivex.rxjava3.functions.BiFunction;
  import io.reactivex.rxjava3.internal.subscriptions.*;
  import io.reactivex.rxjava3.plugins.RxJavaPlugins;
  
  public final class FlowableZipIterable<T, U, V> extends AbstractFlowableWithUpstream<T, V> {
      final Iterable<U> other;
      final BiFunction<? super T, ? super U, ? extends V> zipper;
  
      public FlowableZipIterable(
              Flowable<T> source,
              Iterable<U> other, BiFunction<? super T, ? super U, ? extends V> zipper) {
          super(source);
          this.other = other;
          this.zipper = zipper;
      }
  
      @Override
      public void subscribeActual(Subscriber<? super V> t) {
          Iterator<U> it;
  
          try {
              it = Objects.requireNonNull(other.iterator(), "The iterator returned by other is null");
          } catch (Throwable e) {
              Exceptions.throwIfFatal(e);
              EmptySubscription.error(e, t);
              return;
          }
  
          boolean b;
  
          try {
              b = it.hasNext();
          } catch (Throwable e) {
              Exceptions.throwIfFatal(e);
              EmptySubscription.error(e, t);
              return;
          }
  
          if (!b) {
              EmptySubscription.complete(t);
              return;
          }
  
          source.subscribe(new ZipIterableSubscriber<T, U, V>(t, it, zipper));
      }
  
      static final class ZipIterableSubscriber<T, U, V> implements FlowableSubscriber<T>, Subscription {
          final Subscriber<? super V> downstream;
          final Iterator<U> iterator;
          final BiFunction<? super T, ? super U, ? extends V> zipper;
  
          Subscription upstream;
  
          boolean done;
  
          ZipIterableSubscriber(Subscriber<? super V> actual, Iterator<U> iterator,
                  BiFunction<? super T, ? super U, ? extends V> zipper) {
              this.downstream = actual;
              this.iterator = iterator;
              this.zipper = zipper;
          }
  
          @Override
          public void onSubscribe(Subscription s) {
              if (SubscriptionHelper.validate(this.upstream, s)) {
                  this.upstream = s;
                  downstream.onSubscribe(this);
              }
          }
  
          @Override
          public void onNext(T t) {
              if (done) {
                  return;
              }
  
              U u;
  
              try {
                  u = Objects.requireNonNull(iterator.next(), "The iterator returned a null value");
              } catch (Throwable e) {
                  fail(e);
                  return;
              }
  
              V v;
              try {
                  v = Objects.requireNonNull(zipper.apply(t, u), "The zipper function returned a null value");
              } catch (Throwable e) {
                  fail(e);
                  return;
              }
  
              downstream.onNext(v);
  
              boolean b;
  
              try {
                  b = iterator.hasNext();
              } catch (Throwable e) {
                  fail(e);
                  return;
              }
  
              if (!b) {
                  done = true;
                  upstream.cancel();
                  downstream.onComplete();
              }
          }
  
          void fail(Throwable e) {
              Exceptions.throwIfFatal(e);
              done = true;
              upstream.cancel();
              downstream.onError(e);
          }
  
          @Override
          public void onError(Throwable t) {
              if (done) {
                  RxJavaPlugins.onError(t);
                  return;
              }
              done = true;
              downstream.onError(t);
          }
  
          @Override
          public void onComplete() {
              if (done) {
                  return;
              }
              done = true;
              downstream.onComplete();
          }
  
          @Override
          public void request(long n) {
              upstream.request(n);
          }
  
          @Override
          public void cancel() {
              upstream.cancel();
          }
  
      }
  }
  