package org.davidmoten.kool.internal.operators.stream;
   
   import org.davidmoten.kool.Stream;
   import org.davidmoten.kool.StreamIterable;
   import org.davidmoten.kool.StreamIterator;
   import org.davidmoten.kool.function.Function;
   
   public final class Map<T, R> implements Stream<R> {
   
      private final Function<? super T, ? extends R> function;
      private final StreamIterable<T> source;
  
      public Map(Function<? super T, ? extends R> function, StreamIterable<T> source) {
          this.function = function;
          this.source = source;
  
      }
  
      @Override
      public StreamIterator<R> iterator() {
          return new StreamIterator<R>() {
  
              StreamIterator<T> it = source.iteratorNullChecked();
  
              @Override
              public boolean hasNext() {
                  return it != null && it.hasNext();
              }
  
              @Override
              public R next() {
                  return function.applyUnchecked(it.nextNullChecked());
              }
  
              @Override
              public void dispose() {
                  if (it != null) {
                      it.dispose();
                      it = null;
                  }
              }
  
          };
      }
  
  }