otp.net /Otp/Erlang/List.cs

Language C# Lines 359
MD5 Hash fc5e9435c324a485e8cc3b52837f3c9f Estimated Cost $4,750 (why?)
Repository https://github.com/saleyn/otp.net.git View Raw File View Project SPDX
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
/*``The contents of this file are subject to the Erlang Public License,
* Version 1.1, (the "License"); you may not use this file except in
* compliance with the License. You should have received a copy of the
* Erlang Public License along with this software. If not, it can be
* retrieved via the world wide web at http://www.erlang.org/.
* 
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
* the License for the specific language governing rights and limitations
* under the License.
* 
* The Initial Developer of the Original Code is Ericsson Utvecklings AB.
* Portions created by Ericsson are Copyright 1999, Ericsson Utvecklings
* AB. All Rights Reserved.''
* 
* Converted from Java to C# by Vlad Dumitrescu (vlad_Dumitrescu@hotmail.com)
* Contribution: Serge Aleynikov (added pattern matching)
*/
namespace Otp.Erlang
{
	using System;
    using System.Collections;
    using System.Collections.Generic;
	
	/*
	* Provides a C# representation of Erlang lists. Lists are created
	* from zero or more arbitrary Erlang terms.
	*
	* <p> The arity of the list is the number of elements it contains.
	**/
	[Serializable]
    public class List:Erlang.Object, IEnumerable<Object>
	{
		private Object[] elems;
		
		// todo: use a linked structure to make a proper list with append,
		// car, cdr etc methods. The current representation is essensially the
		// same as for tuples except that empty lists are allowed.
		// private Object car = null;
		// private Object cdr = null;
		// int arity;
		
		/*
		* Create an empty list.
		**/
		public List()
		{
			this.elems = new Object[0]; // empty list
		}
		
		/*
		* Create a list of characters.
		*
		* @param str the characters from which to create the list.
		*
		public List(System.String str)
		{
    		this.elems = new Object[] { new Erlang.String(str) };
		}
		
		* Create a list containing one element.
		*
		* @param elem the elememet to make the list from.
		*
		public List(Object elem)
		{
			this.elems = new Object[1];
			elems[0] = elem;
		}
        */		
        
		/*
        * Create a list from an array of arbitrary Erlang terms.
		*
		* @param elems the array of terms from which to create the list.
		* @param count the number of terms to insert.
		*/
        public List(Object[] elems): this(elems, 0, elems.Length)
        {
        }

		/*
        * Create a list from an array of arbitrary Erlang terms.
		*
		* @param elems the array of terms from which to create the list.
		* @param start the offset of the first term to insert.
		* @param count the number of terms to insert.
		*/
        public List(Object[] elems, int start, int count)
		{
			if ((elems != null) && (count > 0))
			{
				this.elems = new Object[count];
                Array.Copy(elems, 0, this.elems, start, count);
            }
		}

        /*
        * Create a list from an array of arbitrary Erlang terms.
        *
        * @param elems the array of terms from which to create the list.
        **/
        public List(params object[] elems)
        {
            int length = (elems != null) ? elems.Length : 0;
            this.elems = new Object[length];

            for (int i=0; i < length; i++)
            {
                object o = elems[i];
                if (o is int) this.elems[i] = new Int((int)o);
                else if (o is string) this.elems[i] = new String((string)o);
                else if (o is float) this.elems[i] = new Double((float)o);
                else if (o is double) this.elems[i] = new Double((double)o);
                else if (o is Erlang.Object) this.elems[i] = (Erlang.Object)o;
                //else if (o is BigInteger) this.elems[i] = (BigInteger)o;
                else if (o is uint) this.elems[i] = new UInt((int)o);
                else if (o is short) this.elems[i] = new Short((short)o);
                else if (o is ushort) this.elems[i] = new UShort((short)o);
                else if (o is bool) this.elems[i] = new Boolean((bool)o);
                else if (o is char) this.elems[i] = new Char((char)o);
                else
                    throw new System.ArgumentException("Unknown type of element[" + i + "]: " + o.GetType().ToString());
            }
        }

        /*
        * Create a list from a stream containing an list encoded in Erlang
        * external format.
        *
        * @param buf the stream containing the encoded list.
        * 
        * @exception DecodeException if the buffer does not
        * contain a valid external representation of an Erlang list.
        **/
		public List(OtpInputStream buf)
		{
			int arity = buf.read_list_head();

			if (arity < 0)
				arity = 0;

			this.elems = new Object[arity];

			if (arity > 0)
			{
				 for (int i = 0; i < arity; i++)
				{
					elems[i] = buf.read_any();
				}
				
				/*discard the terminating nil (empty list) */
				buf.read_nil();
			}
		}
		
        public override Type Type { get { return GetType(); } }
 
        public override TermType TermType { get { return TermType.List; } }

        /*
		* Get the arity of the list.
		*
		* @return the number of elements contained in the list.
		**/
		public int arity()
		{
			return elems.Length;
		}
		
		/*
		* Get the specified element from the list.
		*
		* @param i the index of the requested element. List elements are
		* numbered as array elements, starting at 0.
		*
		* @return the requested element, of null if i is not a valid
		* element index.
		**/
		public Object elementAt(int i)
		{
			if ((i >= arity()) || (i < 0))
				return null;
			return elems[i];
		}
		
		/*
		* Get all the elements from the list as an array.
		*
		* @return an array containing all of the list's elements. 
		**/
		public Object[] elements()
		{
			if (arity() == 0)
				return null;
			else
			{
				Object[] res = new Object[arity()];
				Array.Copy(this.elems, 0, res, 0, res.Length);
				return res;
			}
		}

        public Object this[int index]
        {
            get { return elementAt(index); }
            set { this.elems[index] = value; }
        }

        public int Length
        {
            get { return this.arity(); }
        }

		/*
		* Get the string representation of the list.
		*
		* @return the string representation of the list.
		**/
		public override System.String ToString()
		{
			System.Text.StringBuilder s = new System.Text.StringBuilder();
			int _arity = arity();
			
			s.Append("[");
			
			 for (int i = 0; i < _arity; i++)
			{
				if (i > 0)
					s.Append(",");
				s.Append(elems[i].ToString());
			}
			
			s.Append("]");
			
			return s.ToString();
		}
		
		/*
		* Convert this list to the equivalent Erlang external
		* representation. Note that this method never encodes lists as
		* strings, even when it is possible to do so.
		*
		* @param buf An output stream to which the encoded list should be
		* written.
		*
		**/
		public override void  encode(OtpOutputStream buf)
		{
			int _arity = arity();
			
			if (_arity > 0)
			{
				buf.write_list_head(_arity);
				
				 for (int i = 0; i < _arity; i++)
				{
					buf.write_any(elems[i]);
				}
			}
			
			buf.write_nil();
		}
		
		/*
		* Determine if two lists are equal. Lists are equal if they have
		* the same arity and all of the elements are equal.
		*
		* @param o the list to compare to.
		*
		* @return true if the lists have the same arity and all the
		* elements are equal.
		**/
		public override bool Equals(System.Object o)
		{
			if (!(o is List))
				return false;
			
			List l = (List) o;
			int a = this.arity();
			
			if (a != l.arity())
				return false;
			
			 for (int i = 0; i < a; i++)
			{
				if (!this.elems[i].Equals(l.elems[i]))
					return false;
				// early exit
			}
			
			return true;
		}

		public override int GetHashCode()
		{
			return 1;
		}

		public override System.Object clone()
		{
			List newList = (List) (base.clone());
			newList.elems = new Object[elems.Length];
			elems.CopyTo(newList.elems, 0);
			return newList;
		}
        
        public override bool subst(ref Erlang.Object a_term, VarBind binding)
        {
            System.Collections.Generic.List<Erlang.Object> result =
                new System.Collections.Generic.List<Erlang.Object>();
            bool changed = false;

            if (this.elems != null)
                foreach (Erlang.Object term in this.elems)
                {
                    Erlang.Object obj = null;
                    if (term.subst(ref obj, binding))
                        result.Add(obj);
                    else
                    {
                        changed = true;
                        result.Add(term);
                    }
                }

            if (!changed)
                return false;

            a_term = new Erlang.List(result.ToArray());
            return true;
        }

        public override bool match(Erlang.Object pattern, VarBind binding)
        {
            if (pattern is Erlang.Var)
                pattern.match(this, binding);
            else if (!(pattern is Erlang.List))
                return false;
            Erlang.List tup = pattern as Erlang.List;
            if (arity() != tup.arity())
                return false;
            for (int i = 0; i < arity(); ++i)
                if (!elems[i].match(tup[i], binding))
                    return false;
            return true;
        }

        IEnumerator<Object> IEnumerable<Object>.GetEnumerator()
        {
            return ((IEnumerable<Object>)elems).GetEnumerator();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return elems.GetEnumerator();
        }
    }
}
Back to Top