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         public class Stack <T> : IEnumerable <T>, ICollection, IEnumerable {
  42
  43                 T [] data;
  44                 int size;
  45                 int ver;
  46                 int defaultCapacity;
  47
  48                 private readonly static int INITIAL_SIZE = 16;
  49
  50                 public Stack ()
  51                 {
  52                         defaultCapacity = INITIAL_SIZE;
  53                 }
  54
  55                 public Stack (int count)
  56                 {
  57                         if (count < 0)
  58                                 throw new ArgumentOutOfRangeException ("count");
  59
  60                         defaultCapacity = count;
  61                         data = new T [count];
  62                 }
  63
  64                 public Stack (IEnumerable <T> collection)
  65                 {
  66                         if (collection == null)
  67                                 throw new ArgumentNullException ("collection");
  68
  69                         ICollection <T> col = collection as ICollection <T>;
  70
  71                         if (col != null) {
  72                                 size = col.Count;
  73                                 data = new T [size];
  74                                 col.CopyTo (data, 0);
  75                         } else {
  76                                 foreach (T t in collection)
  77                                         Push (t);
  78                         }
  79                         defaultCapacity = size;
  80                 }
  81
  82                 public void Clear ()
  83                 {
  84                         if (data != null)
  85                                 Array.Clear (data, 0, data.Length);
  86
  87                         size = 0;
  88                         ver ++;
  89                 }
  90
  91                 public bool Contains (T t)
  92                 {
  93                         return data != null && Array.IndexOf (data, t, 0, size) != -1;
  94                 }
  95
  96                 public void CopyTo (T [] dest, int idx)
  97                 {
  98                         // this gets copied in the order that it is poped
  99                         if (data != null) {
 100                                 Array.Copy (data, 0, dest, idx, size);
 101                                 Array.Reverse (dest, idx, size);
 102                         }
 103                 }
 104
 105                 public T Peek ()
 106                 {
 107                         if (size == 0)
 108                                 throw new InvalidOperationException ();
 109
 110                         ver ++;
 111
 112                         return data [size - 1];
 113                 }
 114
 115                 public T Pop ()
 116                 {
 117                         if (size == 0)
 118                                 throw new InvalidOperationException ();
 119
 120                         ver ++;
 121
 122                         return data [-- size];
 123                 }
 124
 125                 public void Push (T t)
 126                 {
 127                         if (size == 0 || size == data.Length)
 128                                 Array.Resize <T> (ref data, size == 0 ? INITIAL_SIZE : 2 * size);
 129
 130                         ver ++;
 131
 132                         data [size++] = t;
 133                 }
 134
 135                 public T [] ToArray ()
 136                 {
 137                         T [] copy = new T [size];
 138                         CopyTo (copy, 0);
 139                         return copy;
 140                 }
 141
 142                 public void TrimExcess ()
 143                 {
 144                         if (data != null && (size < data.Length * 0.9))
 145                                 Array.Resize <T> (ref data, size == 0 ? defaultCapacity : size);
 146                 }
 147
 148                 public int Count {
 149                         get { return size; }
 150                 }
 151
 152                 bool ICollection.IsSynchronized {
 153                         get { return false; }
 154                 }
 155
 156                 object ICollection.SyncRoot {
 157                         get { return this; }
 158                 }
 159
 160                 void ICollection.CopyTo (Array dest, int idx)
 161                 {
 162                         try {
 163                                 if (data != null) {
 164                                         data.CopyTo (dest, idx);
 165                                         Array.Reverse (dest, idx, size);
 166                                 }
 167                         } catch (ArrayTypeMismatchException) {
 168                                 throw new ArgumentException ();
 169                         }
 170                 }
 171
 172                 public Enumerator GetEnumerator ()
 173                 {
 174                         return new Enumerator (this);
 175                 }
 176
 177                 IEnumerator <T> IEnumerable<T>.GetEnumerator ()
 178                 {
 179                         return GetEnumerator ();
 180                 }
 181
 182                 IEnumerator IEnumerable.GetEnumerator ()
 183                 {
 184                         return GetEnumerator ();
 185                 }
 186
 187                 public struct Enumerator : IEnumerator <T>, IEnumerator, IDisposable {
 188                         const int NOT_STARTED = -2;
 189
 190                         // this MUST be -1, because we depend on it in move next.
 191                         // we just decr the size, so, 0 - 1 == FINISHED
 192                         const int FINISHED = -1;
 193
 194                         Stack <T> parent;
 195                         int idx;
 196                         int ver;
 197
 198                         internal Enumerator (Stack <T> t)
 199                         {
 200                                 parent = t;
 201                                 idx = NOT_STARTED;
 202                                 ver = t.ver;
 203                         }
 204
 205                         // for some fucked up reason, MSFT added a useless dispose to this class
 206                         // It means that in foreach, we must still do a try/finally. Broken, very
 207                         // broken.
 208                         public void Dispose ()
 209                         {
 210                                 idx = NOT_STARTED;
 211                         }
 212
 213                         public bool MoveNext ()
 214                         {
 215                                 if (ver != parent.ver)
 216                                         throw new InvalidOperationException ();
 217
 218                                 if (idx == -2)
 219                                         idx = parent.size;
 220
 221                                 return idx != FINISHED && -- idx != FINISHED;
 222                         }
 223
 224                         public T Current {
 225                                 get {
 226                                         if (idx < 0)
 227                                                 throw new InvalidOperationException ();
 228
 229                                         return parent.data [idx];
 230                                 }
 231                         }
 232
 233                         void IEnumerator.Reset ()
 234                         {
 235                                 if (ver != parent.ver)
 236                                         throw new InvalidOperationException ();
 237
 238                                 idx = NOT_STARTED;
 239                         }
 240
 241                         object IEnumerator.Current {
 242                                 get { return Current; }
 243                         }
 244
 245                 }
 246         }
 247 }
 248 #endif