bundles/org.simantics.utils.datastructures/src/org/simantics/utils/datastructures/ImmutableSList.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management
   3  * in Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.utils.datastructures;
  13
  14 import java.util.Collection;
  15 import java.util.Iterator;
  16 import java.util.NoSuchElementException;
  17
  18
  19 public class ImmutableSList<T> extends ImmutableCollection<T> {
  20
  21         final public T                 head;
  22         final public ImmutableSList<T> tail; // null, if this is the last element
  23
  24         public ImmutableSList(T head, ImmutableSList<T> tail) {
  25                 this.head = head;
  26                 this.tail = tail;
  27         }
  28
  29         public ImmutableSList(T head) {
  30                 this(head, null);
  31         }
  32
  33         @Override
  34         public boolean contains(Object o) {
  35                 ImmutableSList<T> cur = this;
  36                 do {
  37                         if(cur.head.equals(o))
  38                                 return true;
  39                         cur = cur.tail;
  40                 } while(cur != null);
  41                 return false;
  42         }
  43         @Override
  44         public boolean containsAll(Collection<?> c) {
  45                 for(Object o : c)
  46                         if(!contains(o))
  47                                 return false;
  48                 return true;
  49         }
  50         @Override
  51         public boolean isEmpty() {
  52                 return false;
  53         }
  54
  55         static private class Iter<T> implements Iterator<T> {
  56                 public ImmutableSList<T> cur;
  57
  58                 public Iter(ImmutableSList<T> cur) {
  59                         this.cur = cur;
  60                 }
  61
  62                 @Override
  63                 public boolean hasNext() {
  64                         return cur != null;
  65                 }
  66
  67                 @Override
  68                 public T next() {
  69                         if(cur == null)
  70                                 throw new NoSuchElementException();
  71                         T ret = cur.head;
  72                         cur = cur.tail;
  73                         return ret;
  74                 }
  75
  76                 @Override
  77                 public void remove() {
  78                         throw new UnsupportedOperationException();
  79                 }
  80
  81         }
  82
  83         @Override
  84         public Iterator<T> iterator() {
  85                 return new Iter<T>(this);
  86         }
  87         @Override
  88         public int size() {
  89                 ImmutableSList<T> cur = this;
  90                 int count = 0;
  91                 do {
  92                         ++count;
  93                         cur = cur.tail;
  94                 } while(cur != null);
  95                 return count;
  96         }
  97
  98
  99
 100 }