definitelyNotFilter

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package cz.cvut.k36.pr2.hw.hw06.impl;

import cz.cvut.k36.pr2.hw.hw06.Function;
import cz.cvut.k36.pr2.hw.hw06.Pr2List;
import cz.cvut.k36.pr2.hw.hw06.Predicate;
import static cz.cvut.k36.pr2.hw.hw06.impl.ListFactory.nil;
import java.util.Iterator;
import java.util.NoSuchElementException;

/**
 *
 * @author Azathoth
 */
public class NotNilViewFilter<Input> extends NotNilView<Input>{

    private Predicate<Input> predicate;
    protected Pr2List<Input> list;
    Input head=null;

    public NotNilViewFilter(Pr2List list, Predicate predicate) {
        super(list);
        this.list=list;
        this.predicate=predicate;
    }

    @Override
    public boolean isEmpty() {
        if (this.list.isEmpty()) {
            return this.list.isEmpty();
        }
        head=this.list.head();
        if (predicate.apply(head)) {
            return false;
        } else {
            this.list=this.list.tail();
        }
        return this.isEmpty();
    }

    @Override
    public Pr2List filter(Predicate predicate) {
        Pr2List<Input> output=new NotNilViewFilter<Input>(this, predicate);
        return output;
    }

    @Override
    public <Output> Pr2List<Output> map(Function<Input, Output> function){
        Pr2List<Output> output=new NotNilViewMap<Input, Output>(this, function);
        return output;
    }

    @Override
    public Input head() {
        if (isEmpty()) {
            return this.list.head();
        }
        return head;
    }

    @Override
    public Pr2List tail() {
        this.isEmpty();
        NotNilViewFilter<Input> output=new NotNilViewFilter(this.list.tail(), predicate);
        return output;
    }

    @Override
    public Pr2List view() {
        NotNilView<Input> output=new NotNilView(this);
        return output;
    }

    @Override
    public int size() {
        isEmpty();
        return this.list.size();
    }

    @Override
    public Iterator iterator() {
        return new MyIterator();
    }

    @Override
    public String toString() {
        return this.getClass()+", "+this.list.toString();
    }

    private class MyIterator<Input> implements Iterator<Input>{

        Pr2List<Input> iterator=new NotNilViewFilter<>(list,predicate);
        Input head;
        Pr2List<Input> next;

        @Override
        public boolean hasNext() {
            System.out.println("hasNextBegin");
            if (!iterator.equals(nil())) {
                try {
                    next=iterator.tail();
                } catch (UnsupportedOperationException e){
                    return false;
                }
            }
            if (!next.equals(nil())) {
                System.out.println("hasNextEnd");
                return true;
            }
            System.out.println("hasNextEnd");
            return false;
        }

        @Override
        public Input next() {
            System.out.println("nextBegin");
            Input output;
            if (iterator instanceof NotNilViewFilter) {
                NotNilViewFilter<Input> temp=(NotNilViewFilter) iterator;
                head=temp.list.head();
            } else {
                head=iterator.head();
            }
            iterator=next;
            output=head;
            System.out.println("nextEnd");
            return output;
        }

        @Override
        public void remove() {
            throw new UnsupportedOperationException("Z view nejde odebĂ­rat.");
        }
    }

}