org.polarsys.reqcycle.utils.collect.IterableFactory.java Source code

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Here is the source code for org.polarsys.reqcycle.utils.collect.IterableFactory.java

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/*******************************************************************************
 *  Copyright (c) 2013 AtoS
 *  All rights reserved. This program and the accompanying materials
 *  are made available under the terms of the Eclipse Public License v1.0
 *  which accompanies this distribution, and is available at
 *  http://www.eclipse.org/legal/epl-v10.html *
 *  Contributors:
 *    Olivier Melois (AtoS) - initial API and implementation and/or initial documentation
 *   
 *******************************************************************************/
package org.polarsys.reqcycle.utils.collect;

import java.util.Arrays;
import java.util.Collections;

import org.polarsys.reqcycle.utils.collect.collectors.DepthCollector;
import org.polarsys.reqcycle.utils.collect.collectors.WidthCollector;
import org.polarsys.reqcycle.utils.collect.yieldadapters.ThreadedYieldAdapter;

import com.google.common.collect.Iterables;

/**
 * Class that generates iterables, provided a bunch of pickers and a starting element. The iterable created can then be filtered using Guava. These iterables are strictly not collections, and should not be considered as such. Guava provides utilities
 * that should be used if you need to test the uniqueness of an element, for instance...
 */
public class IterableFactory {

    /**
     * Creates a depth wise iterable : in the order given by the caller, the first element returned by {@link Picker#getNexts(Object)} call serves as the parameter for the next call before the second element is processed.
     */
    public static <T> Iterable<T> createIterable(T startingElement, Iterable<? extends Picker<T>> pickers) {
        Collector<T> collector = new DepthCollector<T>(startingElement, pickers);
        YieldAdapter<T> yieldAdapter = new ThreadedYieldAdapter<T>();
        return yieldAdapter.adapt(collector);
    }

    /**
     * Creates a depth wise iterable : in the order given by the caller, the first element returned by {@link Picker#getNexts(Object)} call serves as the parameter for the next call before the second element is processed.
     */
    public static <T> Iterable<T> createIterable(T startingElement, Picker<T>... pickers) {
        Collector<T> collector = new DepthCollector<T>(startingElement, Arrays.asList(pickers));
        YieldAdapter<T> yieldAdapter = new ThreadedYieldAdapter<T>();
        return yieldAdapter.adapt(collector);
    }

    /**
     * Creates a depth wise iterable that concats all the iterables created by the call of createIterable on each of the starting elements.
     */
    public static <T> Iterable<T> createIterable(Iterable<T> startingElements,
            Iterable<? extends Picker<T>> pickers) {
        Iterable<T> result = Collections.emptyList();
        for (T t : startingElements) {
            Iterable<T> tIterable = createIterable(t, pickers);
            result = Iterables.concat(result, tIterable);
        }
        return result;
    }

    /**
     * Creates a depth wise iterable that concats all the iterables created by the call of createIterable on each of the starting elements.
     */
    public static <T> Iterable<T> createIterable(Iterable<T> startingElements, Picker<T> picker) {
        Iterable<T> result = Collections.emptyList();
        for (T t : startingElements) {
            Iterable<T> tIterable = createIterable(t, Collections.singleton(picker));
            result = Iterables.concat(result, tIterable);
        }
        return result;
    }

    /**
     * Creates a depth wise iterable that concats all the iterables created by the call of createIterable on each of the starting elements.
     */
    public static <T> Iterable<T> createIterable(Iterable<T> startingElements, Picker<T>... pickers) {
        Iterable<T> result = Collections.emptyList();
        for (T t : startingElements) {
            Iterable<T> tIterable = createIterable(t, pickers);
            result = Iterables.concat(result, tIterable);
        }
        return result;
    }

    /**
     * Creates a depth wise iterable : in the order given by the caller, the first element returned by {@link Picker#getNexts(Object)} call serves as the parameter for the next call before the second element is processed.
     */
    public static <T> Iterable<T> createWidthWiseIterable(T startingElement,
            Iterable<? extends Picker<T>> pickers) {
        Collector<T> collector = new WidthCollector<T>(startingElement, pickers);
        YieldAdapter<T> yieldAdapter = new ThreadedYieldAdapter<T>();
        return yieldAdapter.adapt(collector);
    }

    /**
     * Creates a depth wise iterable : in the order given by the caller, the first element returned by {@link Picker#getNexts(Object)} call serves as the parameter for the next call before the second element is processed.
     */
    public static <T> Iterable<T> createWidthWiseIterable(T startingElement, Picker<T>... pickers) {
        Collector<T> collector = new WidthCollector<T>(startingElement, Arrays.asList(pickers));
        YieldAdapter<T> yieldAdapter = new ThreadedYieldAdapter<T>();
        return yieldAdapter.adapt(collector);
    }

    /**
     * Creates a width wise iterable that iterates over starting elements and then on the concatenation on the call of createWidthWiseIterable on each of these elements.
     */
    public static <T> Iterable<T> createWidthWiseIterable(Iterable<T> startingElements,
            Iterable<? extends Picker<T>> pickers) {
        Collector<T> collector = new WidthCollector<T>(startingElements, pickers);
        YieldAdapter<T> yieldAdapter = new ThreadedYieldAdapter<T>();
        return yieldAdapter.adapt(collector);
    }

}