BaseList.java

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package org.hsqldb.lib;

import java.util.NoSuchElementException;

/**
 * Abstract base for Lists
 *
 * @author Fred Toussi (fredt@users dot sourceforge.net)
 * @version 2.7.3
 * @since 1.7.0
 */
abstract class BaseList<E> {

    protected ObjectComparator<E> comparator =
        ObjectComparator.defaultComparator;
    protected int elementCount;

    public abstract E get(int index);

    public abstract E remove(int index);

    public abstract boolean add(E element);

    public abstract int size();

    public boolean contains(Object element) {

        for (int i = 0, size = size(); i < size; i++) {
            E current = get(i);

            if (comparator.equals(current, (E) element)) {
                return true;
            }
        }

        return false;
    }

    public int indexOf(E element) {

        for (int i = 0, size = size(); i < size; i++) {
            E current = get(i);

            if (comparator.equals(current, element)) {
                return i;
            }
        }

        return -1;
    }

    public boolean addAll(Collection<? extends E> other) {

        boolean               result = false;
        Iterator<? extends E> it     = other.iterator();

        while (it.hasNext()) {
            result = true;

            add(it.next());
        }

        return result;
    }

    public boolean addAll(E[] array) {

        boolean result = false;

        for (E object: array) {
            result = true;

            add(object);
        }

        return result;
    }

    public boolean isEmpty() {
        return elementCount == 0;
    }

    public String toString() {

        StringBuilder sb = new StringBuilder(32 + elementCount * 3);

        sb.append("List : size=");
        sb.append(elementCount);
        sb.append(' ');
        sb.append('{');

        Iterator<?> it = iterator();

        while (it.hasNext()) {
            sb.append(it.next());

            if (it.hasNext()) {
                sb.append(',');
                sb.append(' ');
            }
        }

        sb.append('}');

        return sb.toString();
    }

    public Iterator<E> iterator() {
        return new BaseListIterator();
    }

    private class BaseListIterator implements Iterator<E> {

        int     counter = 0;
        boolean removed;

        public boolean hasNext() {
            return counter < elementCount;
        }

        public E next() {

            if (counter < elementCount) {
                removed = false;

                E returnValue = get(counter);

                counter++;

                return returnValue;
            }

            throw new NoSuchElementException();
        }

        public int nextInt() {
            throw new NoSuchElementException();
        }

        public long nextLong() {
            throw new NoSuchElementException();
        }

        public void remove() {

            if (removed) {
                throw new NoSuchElementException("Iterator");
            }

            removed = true;

            if (counter != 0) {
                BaseList.this.remove(counter - 1);

                counter--;    // above can throw, so decrement if successful

                return;
            }

            throw new NoSuchElementException();
        }
    }
}