Java 类org.apache.commons.collections4.iterators.PeekingIterator 实例源码

/**
 * Writes the definitions of all variable sets defined by the given bindings.
 */
protected void writeVarSets( int varSetLevel, Iterator<VarBinding> varBindings)
  {
  xmlWriter_.writeTagStart( "TABLE");
  xmlWriter_.writeAttribute( "class", varSetLevel % 2 == 0? "light" : "dark");
  xmlWriter_.writeTagEnd();
  xmlWriter_.indent();

  String varSet = "";
  String varSetNext = "";
  for( PeekingIterator<VarBinding> peekBindings = new PeekingIterator<VarBinding>( varBindings);
       peekBindings.hasNext();
       varSet = varSetNext)
    {
    List<VarBinding> varSetBindings = new ArrayList<VarBinding>();
    for( varSetNext = "";

         peekBindings.hasNext()
           && (varSetNext = getVarSet( varSetLevel, peekBindings.peek())).equals( varSet);

         varSetBindings.add( peekBindings.next()));

    writeVarSet( varSet, varSetLevel, varSetBindings.iterator());
    }

  xmlWriter_.unindent();
  xmlWriter_.writeElementEnd( "TABLE");
  }

public DOM transform(DOM dom) throws IOException {
    this.dom = new DOM();
    this.dom.setLines(dom.getLines());
    this.dom.setSource(dom.getSource());
    iterator = new PeekingIterator<>(dom.iterator());

    while (iterator.hasNext()) {
        Node n = iterator.next();
        dispatch(n);
    }
    return this.dom;
}

@Override
public Iterator<Pair<State, String>> iterator() {
    return new Iterator<Pair<State, String>>() {
        private Iterator<State> states = ts.getNodes().iterator();
        private State currentState = null;
        private PeekingIterator<String> alphabet = null;

        @Override
        public boolean hasNext() {
            while (true) {
                if (alphabet == null || !alphabet.hasNext()) {
                    if (!states.hasNext())
                        return false;

                    currentState = states.next();
                    alphabet = peekingIterator(ts.getAlphabet().iterator());
                } else {
                    if (!SeparationUtility.isEventEnabled(currentState,
                                alphabet.peek()))
                        return true;
                    alphabet.next();
                }
            }
        }

        @Override
        public Pair<State, String> next() {
            if (!hasNext())
                throw new NoSuchElementException();
            return new Pair<>(currentState, alphabet.next());
        }

        @Override
        public void remove() {
            throw new UnsupportedOperationException();
        }
    };
}

@Override
public Iterator<Set<E>> iterator() {
    return new Iterator<Set<E>>() {
        private PeekingIterator<Set<E>> iter = peekingIterator(leaderToClass.values().iterator());

        @Override
        public boolean hasNext() {
            // Skip all sets which have just a single entry
            Set<E> next = iter.peek();
            while (next != null && next.size() == 1) {
                iter.next();
                iter.remove();
                next = iter.peek();
            }
            return iter.hasNext();
        }

        @Override
        public Set<E> next() {
            hasNext();
            return Collections.unmodifiableSet(iter.next());
        }

        @Override
        public void remove() {
            throw new UnsupportedOperationException();
        }
    };
}

/**
 * Gets an iterator that supports one-element lookahead.
 *
 * @param <E> the element type
 * @param iterator  the iterator to decorate, not null
 * @return a peeking iterator
 * @throws NullPointerException if the iterator is null
 * @since 4.0
 */
public static <E> Iterator<E> peekingIterator(final Iterator<? extends E> iterator) {
    return PeekingIterator.peekingIterator(iterator);
}

/**
 * Gets an iterator that supports one-element lookahead.
 *
 * @param <E> the element type
 * @param iterator  the iterator to decorate, not null
 * @return a peeking iterator
 * @throws NullPointerException if the iterator is null
 * @since 4.0
 */
public static <E> Iterator<E> peekingIterator(final Iterator<? extends E> iterator) {
    return PeekingIterator.peekingIterator(iterator);
}