Java List Value Add add(List list, int i, T v)

Description

Adds the element i in list, as in List#add(int,Object) , but independently on list.size().

License

Creative Commons License

Declaration

public static <T> void add(List<T> list, int i, T v) 

Method Source Code

//package com.java2s;
/*//  www .  j a  va 2  s  .  c om
 * __________
 * CREDITS
 * __________
 *
 * Team page: http://isatab.sf.net/
 * - Marco Brandizi (software engineer: ISAvalidator, ISAconverter, BII data management utility, BII model)
 * - Eamonn Maguire (software engineer: ISAcreator, ISAcreator configurator, ISAvalidator, ISAconverter,  BII data management utility, BII web)
 * - Nataliya Sklyar (software engineer: BII web application, BII model,  BII data management utility)
 * - Philippe Rocca-Serra (technical coordinator: user requirements and standards compliance for ISA software, ISA-tab format specification, BII model, ISAcreator wizard, ontology)
 * - Susanna-Assunta Sansone (coordinator: ISA infrastructure design, standards compliance, ISA-tab format specification, BII model, funds raising)
 *
 * Contributors:
 * - Manon Delahaye (ISA team trainee:  BII web services)
 * - Richard Evans (ISA team trainee: rISAtab)
 *
 *
 * ______________________
 * Contacts and Feedback:
 * ______________________
 *
 * Project overview: http://isatab.sourceforge.net/
 *
 * To follow general discussion: isatab-devel@list.sourceforge.net
 * To contact the developers: isatools@googlegroups.com
 *
 * To report bugs: http://sourceforge.net/tracker/?group_id=215183&atid=1032649
 * To request enhancements:  http://sourceforge.net/tracker/?group_id=215183&atid=1032652
 *
 *
 * __________
 * License:
 * __________
 *
 * This work is licenced under the Creative Commons Attribution-Share Alike 2.0 UK: England & Wales License. To view a copy of this licence, visit http://creativecommons.org/licenses/by-sa/2.0/uk/ or send a letter to Creative Commons, 171 Second Street, Suite 300, San Francisco, California 94105, USA.
 *
 * __________
 * Sponsors
 * __________
 * This work has been funded mainly by the EU Carcinogenomics (http://www.carcinogenomics.eu) [PL 037712] and in part by the
 * EU NuGO [NoE 503630](http://www.nugo.org/everyone) projects and in part by EMBL-EBI.
 */

import java.util.List;

public class Main {
    /**
     * Adds the element i in list, as in {@link List#add(int, Object)}, but independently on list.size(). That is: calls 
     * list.add (i, v) if i <= list.size() (and shifts all elements from i upward as usually), calls 
     * {@link #set(List, int, Object) set ( list, i, v)} otherwise (i.e.: adds null element up to i-1 and v as last 
     * element).  
     *  
     */
    public static <T> void add(List<T> list, int i, T v) {
        if (i <= list.size())
            list.add(i, v);
        else
            set(list, i, v);
    }

    /**
     * Sets the element i in list, independently on the list size. That is: if i < list.size() calls list.set (i, v), 
     * otherwise adds i - list.size() null elements to list and then adds v as the last element, which will be the i element. 
     * 
     */
    public static <T> T set(List<T> list, int i, T v) {
        int sz = list.size();
        if (i == sz) {
            list.add(v);
            return null;
        } else if (i > sz) {
            for (int j = sz; j < i; j++) {
                assert (list.size() == j) : "Internal error: loop invariant in ListUtils.set() violated!";
                // Proof: base is trivial. Recursion: from list.sz == j, you increase sz with add and j with incr. step 
                list.add(null);
            }
            assert (list.size() == i) : "Internal error: loop-end assertion in ListUtils.set() violated!";
            // Proof: trivial, from the loop invariant + the end condition

            list.add(v);
            return null;
        } else
            return list.set(i, v);
    }
}

Related

1. add(List a, List b)
2. add(List list, String value)
3. add(List aList, T anObj)
4. add(List aList, T anObject)
5. add(List current, T toAdd)
6. add(List list, T element)
7. add(Map> multiValueMap, String key, Object value)
8. add(Object o, List oldList)
9. addElement(T element, List list)