mcs/class/System/System.Collections.Generic/Stack.cs

   1 //
   2 // System.Collections.Generic.Stack
   3 //
   4 // Authors:
   5 //      Martin Baulig (martin@ximian.com)
   6 //      Ben Maurer (bmaurer@ximian.com)
   7 //
   8 // (C) 2003, 2004 Novell, Inc.
   9 //
  10
  11 //
  12 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  13 //
  14 // Permission is hereby granted, free of charge, to any person obtaining
  15 // a copy of this software and associated documentation files (the
  16 // "Software"), to deal in the Software without restriction, including
  17 // without limitation the rights to use, copy, modify, merge, publish,
  18 // distribute, sublicense, and/or sell copies of the Software, and to
  19 // permit persons to whom the Software is furnished to do so, subject to
  20 // the following conditions:
  21 //
  22 // The above copyright notice and this permission notice shall be
  23 // included in all copies or substantial portions of the Software.
  24 //
  25 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  29 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  30 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  31 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  32 //
  33
  34 #if NET_2_0
  35 using System;
  36 using System.Runtime.InteropServices;
  37
  38 namespace System.Collections.Generic
  39 {
  40         [ComVisible (false)]
  41         [Serializable]
  42         public class Stack <T> : IEnumerable <T>, ICollection, IEnumerable
  43         {
  44                 T [] _array;
  45                 int _size;
  46                 int _version;
  47
  48                 private const int INITIAL_SIZE = 16;
  49
  50                 public Stack ()
  51                 {
  52                 }
  53
  54                 public Stack (int count)
  55                 {
  56                         if (count < 0)
  57                                 throw new ArgumentOutOfRangeException ("count");
  58
  59                         _array = new T [count];
  60                 }
  61
  62                 public Stack (IEnumerable <T> collection)
  63                 {
  64                         if (collection == null)
  65                                 throw new ArgumentNullException ("collection");
  66
  67                         ICollection <T> col = collection as ICollection <T>;
  68
  69                         if (col != null) {
  70                                 _size = col.Count;
  71                                 _array = new T [_size];
  72                                 col.CopyTo (_array, 0);
  73                         } else {
  74                                 foreach (T t in collection)
  75                                         Push (t);
  76                         }
  77                 }
  78
  79                 public void Clear ()
  80                 {
  81                         if (_array != null)
  82                                 Array.Clear (_array, 0, _array.Length);
  83
  84                         _size = 0;
  85                         _version ++;
  86                 }
  87
  88                 public bool Contains (T t)
  89                 {
  90                         return _array != null && Array.IndexOf (_array, t, 0, _size) != -1;
  91                 }
  92
  93                 public void CopyTo (T [] dest, int idx)
  94                 {
  95                         if (dest == null)
  96                                 throw new ArgumentNullException ("dest");
  97                         if (idx < 0)
  98                                 throw new ArgumentOutOfRangeException ("idx");
  99
 100                         // this gets copied in the order that it is poped
 101                         if (_array != null) {
 102                                 Array.Copy (_array, 0, dest, idx, _size);
 103                                 Array.Reverse (dest, idx, _size);
 104                         }
 105                 }
 106
 107                 public T Peek ()
 108                 {
 109                         if (_size == 0)
 110                                 throw new InvalidOperationException ();
 111
 112                         return _array [_size - 1];
 113                 }
 114
 115                 public T Pop ()
 116                 {
 117                         if (_size == 0)
 118                                 throw new InvalidOperationException ();
 119
 120                         _version ++;
 121                         T popped = _array [--_size];
 122                         // clear stuff out to make the GC happy
 123                         _array [_size] = default(T);
 124                         return popped;
 125                 }
 126
 127                 public void Push (T t)
 128                 {
 129                         if (_array == null || _size == _array.Length)
 130                                 Array.Resize <T> (ref _array, _size == 0 ? INITIAL_SIZE : 2 * _size);
 131
 132                         _version ++;
 133
 134                         _array [_size++] = t;
 135                 }
 136
 137                 public T [] ToArray ()
 138                 {
 139                         T [] copy = new T [_size];
 140                         CopyTo (copy, 0);
 141                         return copy;
 142                 }
 143
 144                 public void TrimExcess ()
 145                 {
 146                         if (_array != null && (_size < _array.Length * 0.9))
 147                                 Array.Resize <T> (ref _array, _size);
 148                         _version ++;
 149                 }
 150
 151                 public int Count {
 152                         get { return _size; }
 153                 }
 154
 155                 bool ICollection.IsSynchronized {
 156                         get { return false; }
 157                 }
 158
 159                 object ICollection.SyncRoot {
 160                         get { return this; }
 161                 }
 162
 163                 void ICollection.CopyTo (Array dest, int idx)
 164                 {
 165                         try {
 166                                 if (_array != null) {
 167                                         _array.CopyTo (dest, idx);
 168                                         Array.Reverse (dest, idx, _size);
 169                                 }
 170                         } catch (ArrayTypeMismatchException) {
 171                                 throw new ArgumentException ();
 172                         }
 173                 }
 174
 175                 public Enumerator GetEnumerator ()
 176                 {
 177                         return new Enumerator (this);
 178                 }
 179
 180                 IEnumerator <T> IEnumerable<T>.GetEnumerator ()
 181                 {
 182                         return GetEnumerator ();
 183                 }
 184
 185                 IEnumerator IEnumerable.GetEnumerator ()
 186                 {
 187                         return GetEnumerator ();
 188                 }
 189
 190                 [Serializable]
 191                 public struct Enumerator : IEnumerator <T>, IEnumerator, IDisposable {
 192                         const int NOT_STARTED = -2;
 193
 194                         // this MUST be -1, because we depend on it in move next.
 195                         // we just decr the _size, so, 0 - 1 == FINISHED
 196                         const int FINISHED = -1;
 197
 198                         Stack <T> parent;
 199                         int idx;
 200                         int _version;
 201
 202                         internal Enumerator (Stack <T> t)
 203                         {
 204                                 parent = t;
 205                                 idx = NOT_STARTED;
 206                                 _version = t._version;
 207                         }
 208
 209                         // for some fucked up reason, MSFT added a useless dispose to this class
 210                         // It means that in foreach, we must still do a try/finally. Broken, very
 211                         // broken.
 212                         public void Dispose ()
 213                         {
 214                                 idx = NOT_STARTED;
 215                         }
 216
 217                         public bool MoveNext ()
 218                         {
 219                                 if (_version != parent._version)
 220                                         throw new InvalidOperationException ();
 221
 222                                 if (idx == -2)
 223                                         idx = parent._size;
 224
 225                                 return idx != FINISHED && -- idx != FINISHED;
 226                         }
 227
 228                         public T Current {
 229                                 get {
 230                                         if (idx < 0)
 231                                                 throw new InvalidOperationException ();
 232
 233                                         return parent._array [idx];
 234                                 }
 235                         }
 236
 237                         void IEnumerator.Reset ()
 238                         {
 239                                 if (_version != parent._version)
 240                                         throw new InvalidOperationException ();
 241
 242                                 idx = NOT_STARTED;
 243                         }
 244
 245                         object IEnumerator.Current {
 246                                 get { return Current; }
 247                         }
 248
 249                 }
 250         }
 251 }
 252 #endif