So I am attempting to create a LinkedHashedDictionary's Iterator member for a homework assignment, however I am having multiple issues regarding its types.
Iterator Interface:
package nhUtilities.containers2;
public interface Iterator<Element> extends Cloneable, java.util.Iterator<Element>
{
public void reset ();
public void advance ();
public boolean done ();
public Element get ();
public boolean equals (Object obj);
public boolean traverses (Object container);
public Object clone ();
public void setEqualTo (Iterator<Element> other);
public boolean hasNext ();
public Element next ();
public void remove ();
}
In my code, I have a private class called EntryIterator. It extends an AbstractIterator, but implements the Iterator above.
My current implementation is as follows:
private class EntryIterator<Element> extends AbstractIterator<Element>
implements Iterator<Element>
{
protected Iterator<Key> keyIterator;
protected Dictionary<Key,Value> dictionary;
public EntryIterator(Dictionary<Key,Value> dictionary)
{
keyIterator = keys.iterator();
this.dictionary = dictionary;
}
public void reset()
{ keyIterator = keys.iterator(); }
/**
* @Requrie !this.done()
*/
public void advance()
{ keyIterator.advance(); }
public boolean done()
{ return keyIterator.done(); }
// public Entry<Key,Value> get()
// Violates initial Interface: Results in compile error.
// Return type must be "Element"
public Element get()
{
Key key = keyIterator.get();
Value value = dictionary.get(keyIterator.get());
return (Element) new Entry<Key,Value>(key, value);
}
public boolean traverses(Object container)
{
// TODO Iterator traverses
return false;
}
public void setEqualTo(Iterator<Element> other)
{
this.keyIterator = ((EntryIterator<Element>) other).keyIterator;
this.dictionary = ((EntryIterator<Element>) other).dictionary;
}
}
I have done multiple varieties of this class regarding its types, but none of them seem to be compatible with my Dictionary. Should I keep the formatting as is above, I get an error on my Dictionary's iterator() function:
public Iterator<Entry<Key,Value>> iterator()
{
return new EntryIterator<Entry<Key,Value>>(this);
}
The error states it is "The return type is incompatible for Dictionary.iterator()"
Should I change the type of the EntryIterator class' type to:
private class EntryIterator<eEntry<Key,Value>> extends AbstractIterator<Element>
implements Iterator<Element>
I simply get an error saying "Syntax error expected on token '<'" as well as another incompatibility error on my Dictionary.Iterator() function.
Can someone point me in the right direction as to how I can link up all of these different types to get them to return what my contract for Dictionary demands?
I have attempted asking my question during the class, via email to the instructor, as well as one on one merely to be avoided. Any help would be much appreciated.
