ListPicker.java

Go to the documentation of this file.

/*
    Synthia, a data structure generator
    Copyright (C) 2019-2020 Laboratoire d'informatique formelle
    Université du Québec à Chicoutimi, Canada
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published
    by the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
 
    This program 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 Lesser General Public License for more details.
 
    You should have received a copy of the GNU Lesser General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package ca.uqac.lif.synthia.collection;
 
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
 
import ca.uqac.lif.synthia.Picker;
import ca.uqac.lif.synthia.util.Constant;
 
/**
 * Picker that merges the result of other pickers into a list.
 * @ingroup API
 */
public class ListPicker extends CompositePicker<List<Object>>
{
    protected Picker<Integer> m_sizePicker;
 
 
    /**
     * Default constructor using a constant list size.
     * @param pickers The array of pickers used to generate the values
     */
    public ListPicker(Picker<?> ... pickers)
    {
        super(pickers);
        m_sizePicker = new Constant<>(pickers.length);
    }
 
    /**
     * Constructor who takes a {@link ca.uqac.lif.synthia.Picker<Integer>} to determine the size of
     * the list returned by the {@link #pick()} method.
     *
     * @param size_picker A picker who picks the size of the list returned by
     *                    the {@link #pick()} method.
     * @param pickers A list of {@link ca.uqac.lif.synthia.Picker} used to produce lists of values.
     */
    public ListPicker(Picker<Integer> size_picker, Picker<?>... pickers)
    {
        super(pickers);
        m_sizePicker = size_picker;
    }
 
    /**
     * Returns a new list picker. This version will return an instance who returns lists of constant
     * size with {@link #pick()} method.
     *
     * @param pickers The pickers used to generate the values
     * @return A new instance of {@link ListPicker}.
     */
    @Override
    public ListPicker newPicker(Picker<?> ... pickers)
    {
        return new ListPicker(pickers);
    }
 
    /**
     * Returns a new list picker. This version will return an instance who returns lists of variable
     * size with {@link #pick()} method. The size of the lists returned by the {@link #pick()} method
     * is determined by a {@link ca.uqac.lif.synthia.Picker<Integer>}.
     *
     * @param size_picker A picker who picks the size of the list returned by
     *                    the {@link #pick()} method.
     * @param pickers A list of {@link ca.uqac.lif.synthia.Picker} used to produce lists of values.
     * @return A new instance of {@link ListPicker}.
     */
    public ListPicker newPicker(Picker<Integer> size_picker, Picker<?>... pickers)
    {
        return new ListPicker(size_picker, pickers);
    }
 
    /**
     * Return a list of values
     * @param values The values to return
     * @return The values
     */
    @Override
    public List<Object> getOutput(Object ... values)
    {
        List<Object> list = new ArrayList<>(values.length);
        Collections.addAll(list, values);
        return list;
    }
 
    @Override
    public List<Object> pick ()
    {
        List<Object> picked_elements = new ArrayList<>();
        int size = m_sizePicker.pick();
        int index =0;
 
        for (int i = 0; i < size; i++)
        {
            picked_elements.add(m_pickers[index].pick());
            index++;
 
            // reset index if size >= m_pickers.length
            if (index == m_pickers.length)
            {
                index = 0;
            }
        }
 
        return picked_elements;
    }
 
    @Override
    public void reset()
    {
        super.reset(); //reset m_pickers
        m_sizePicker.reset();
    }
 
    @Override
    public ListPicker duplicate(boolean with_state)
    {
        return newPicker(m_sizePicker.duplicate(with_state), super.duplicateM_pickers(with_state));
    }
}