/**

 * Copyright 2011 The ARIES Consortium (http://www.ariesonline.org) and

 * www.integratedmodelling.org. 



   This file is part of Thinklab.



   Thinklab is free software: you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published

   by the Free Software Foundation, either version 3 of the License,

   or (at your option) any later version.



   Thinklab is distributed in the hope that it will be useful, but

   WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   General Public License for more details.



   You should have received a copy of the GNU General Public License

   along with Thinklab.  If not, see <http://www.gnu.org/licenses/>.

 */

package org.integratedmodelling.clojure.utils;



import java.util.Collection;

import java.util.Iterator;



import org.integratedmodelling.thinklab.exception.ThinklabRuntimeException;

import org.integratedmodelling.utils.Pair;



/**

 * Pass a collection (e.g. a clojure list of :kw value pairs) and retrieve pairs of key/value with the key 

 * converted to a string and the leading colon removed. Also performs minimal error checking and is null-tolerant.

 * 

 * @author Ferdinando

 *

 */

public class OptionListIterator implements Iterator<Pair<String, Object>> {



	Iterator<?> _it = null;

	

	public OptionListIterator(Object o) {

		if (o != null)

			_it = ((Collection<?>)o).iterator();

	}

	

	@Override

	public boolean hasNext() {

		return _it == null ? false : _it.hasNext();

	}



	@Override

	public Pair<String, Object> next() {

		String key = _it.next().toString();

		Object val = _it.next();

		if (!key.startsWith(":"))

			throw new ThinklabRuntimeException("keyword list improperly formatted: key is not a clojure keyword");

		key = key.substring(1);

		return new Pair<String, Object>(key, val);

	}



	@Override

	public void remove() {

		_it.remove();

		_it.remove();

	}



}