mcs/class/System.XML/System.Xml.XPath/Expression.cs

   1 //
   2 // System.Xml.XPath.XPathExpression support classes
   3 //
   4 // Author:
   5 //   Piers Haken (piersh@friskit.com)
   6 //
   7 // (C) 2002 Piers Haken
   8 //
   9
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30 using System;
  31 using System.IO;
  32 using System.Collections;
  33 using System.Xml;
  34 using System.Xml.XPath;
  35 using System.Xml.Xsl;
  36 using System.Globalization;
  37 using Mono.Xml.XPath;
  38
  39 #if NET_2_0
  40 using NSResolver = System.Xml.IXmlNamespaceResolver;
  41 #else
  42 using NSResolver = System.Xml.XmlNamespaceManager;
  43 #endif
  44
  45 namespace System.Xml.XPath
  46 {
  47 #if XPATH_DEBUG
  48         internal class CompiledExpression : Test.Xml.XPath.XPathExpression
  49 #else
  50         internal class CompiledExpression : XPathExpression
  51 #endif
  52         {
  53                 protected NSResolver _nsm;
  54                 protected Expression _expr;
  55                 XPathSorters _sorters;
  56                 string rawExpression;
  57
  58                 public CompiledExpression (string raw, Expression expr)
  59                 {
  60                         _expr = expr.Optimize ();
  61                         rawExpression = raw;
  62                 }
  63                 private CompiledExpression (CompiledExpression other)
  64                 {
  65                         _nsm = other._nsm;
  66                         _expr = other._expr;
  67                         rawExpression = other.rawExpression;
  68                 }
  69 #if XPATH_DEBUG
  70                 public override Test.Xml.XPath.XPathExpression Clone () { return new CompiledExpression (this); }
  71 #else
  72                 public override XPathExpression Clone () { return new CompiledExpression (this); }
  73 #endif
  74
  75                 public Expression ExpressionNode { get { return _expr; }}
  76
  77                 public override void SetContext (XmlNamespaceManager nsManager)
  78                 {
  79                         _nsm = nsManager;
  80                 }
  81
  82 #if NET_2_0
  83                 public override void SetContext (IXmlNamespaceResolver nsResolver)
  84                 {
  85                         _nsm = nsResolver;
  86                 }
  87 #endif
  88
  89                 internal NSResolver NamespaceManager { get { return _nsm; } }
  90                 public override String Expression { get { return rawExpression; }}
  91                 public override XPathResultType ReturnType { get { return _expr.ReturnType; }}
  92
  93                 public object Evaluate (BaseIterator iter)
  94                 {
  95                         if (_sorters != null)
  96                                 return EvaluateNodeSet (iter);
  97
  98                         try {
  99                                 return _expr.Evaluate (iter);
 100                         }
 101                         catch (XPathException) {
 102                                 throw;
 103                         }
 104                         catch (XsltException) {
 105                                 throw;
 106                         }
 107                         catch (Exception e) {
 108                                 throw new XPathException ("Error during evaluation", e);
 109                         }
 110                 }
 111                 public XPathNodeIterator EvaluateNodeSet (BaseIterator iter)
 112                 {
 113 #if false
 114                         try
 115                         {
 116 #endif
 117                                 BaseIterator iterResults = (BaseIterator) _expr.EvaluateNodeSet (iter);
 118                                 if (_sorters != null)
 119                                         return _sorters.Sort (iterResults);
 120                                 return iterResults;
 121 #if false
 122                         }
 123                         catch (XPathException)
 124                         {
 125                                 throw;
 126                         }
 127                         catch (Exception e)
 128                         {
 129                                 throw new XPathException ("Error during evaluation", e);
 130                         }
 131 #endif
 132                 }
 133                 public double EvaluateNumber (BaseIterator iter)
 134                 {
 135 #if true
 136                         return _expr.EvaluateNumber (iter);
 137 #else
 138                         try
 139                         {
 140                                 return _expr.EvaluateNumber (iter);
 141                         }
 142                         catch (XPathException)
 143                         {
 144                                 throw;
 145                         }
 146                         catch (Exception e)
 147                         {
 148                                 throw new XPathException ("Error during evaluation", e);
 149                         }
 150 #endif
 151                 }
 152                 public string EvaluateString (BaseIterator iter)
 153                 {
 154 #if true
 155                         return _expr.EvaluateString (iter);
 156 #else
 157                         try
 158                         {
 159                                 return _expr.EvaluateString (iter);
 160                         }
 161                         catch (XPathException)
 162                         {
 163                                 throw;
 164                         }
 165                         catch (Exception e)
 166                         {
 167                                 throw new XPathException ("Error during evaluation", e);
 168                         }
 169 #endif
 170                 }
 171                 public bool EvaluateBoolean (BaseIterator iter)
 172                 {
 173 #if true
 174                         return _expr.EvaluateBoolean (iter);
 175 #else
 176                         try
 177                         {
 178                                 return _expr.EvaluateBoolean (iter);
 179                         }
 180                         catch (XPathException)
 181                         {
 182                                 throw;
 183                         }
 184                         catch (Exception e)
 185                         {
 186                                 throw new XPathException ("Error during evaluation", e);
 187                         }
 188 #endif
 189                 }
 190
 191                 public override void AddSort (Object obj, IComparer cmp)
 192                 {
 193                         if (_sorters == null)
 194                                 _sorters = new XPathSorters ();
 195                         _sorters.Add (obj, cmp);
 196                 }
 197                 public override void AddSort(object expr, XmlSortOrder orderSort, XmlCaseOrder orderCase, string lang, XmlDataType dataType)
 198                 {
 199                         if (_sorters == null)
 200                                 _sorters = new XPathSorters ();
 201                         _sorters.Add (expr, orderSort, orderCase, lang, dataType);
 202                 }
 203
 204                 class XPathSorters : IComparer
 205                 {
 206                         readonly ArrayList _rgSorters = new ArrayList ();
 207
 208                         public void Add (object expr, IComparer cmp)
 209                         {
 210                                 _rgSorters.Add (new XPathSorter (expr, cmp));
 211                         }
 212
 213                         public void Add (object expr, XmlSortOrder orderSort, XmlCaseOrder orderCase, string lang, XmlDataType dataType)
 214                         {
 215                                 _rgSorters.Add (new XPathSorter (expr, orderSort, orderCase, lang, dataType));
 216                         }
 217
 218                         public BaseIterator Sort (BaseIterator iter)
 219                         {
 220                                 ArrayList rgElts = new ArrayList ();
 221                                 int cSorters = _rgSorters.Count;
 222                                 while (iter.MoveNext ())
 223                                 {
 224                                         XPathSortElement elt = new XPathSortElement ();
 225                                         elt.Navigator = iter.Current.Clone ();
 226                                         elt.Values = new object [cSorters];
 227                                         for (int iSorter = 0; iSorter < _rgSorters.Count; ++iSorter)
 228                                         {
 229                                                 XPathSorter sorter = (XPathSorter) _rgSorters [iSorter];
 230                                                 elt.Values [iSorter] = sorter.Evaluate (iter);
 231                                         }
 232                                         rgElts.Add (elt);
 233                                 }
 234                                 rgElts.Sort (this);
 235                                 XPathNavigator [] rgResults = new XPathNavigator [rgElts.Count];
 236                                 for (int iResult = 0; iResult < rgElts.Count; ++iResult)
 237                                 {
 238                                         XPathSortElement elt = (XPathSortElement) rgElts [iResult];
 239                                         rgResults [iResult] = elt.Navigator;
 240                                 }
 241                                 return new ListIterator (iter, rgResults, false);
 242                         }
 243
 244                         class XPathSortElement
 245                         {
 246                                 public XPathNavigator Navigator;
 247                                 public object [] Values;
 248                         }
 249
 250                         int IComparer.Compare (object o1, object o2)
 251                         {
 252                                 XPathSortElement elt1 = (XPathSortElement) o1;
 253                                 XPathSortElement elt2 = (XPathSortElement) o2;
 254                                 for (int iSorter = 0; iSorter < _rgSorters.Count; ++iSorter)
 255                                 {
 256                                         XPathSorter sorter = (XPathSorter) _rgSorters [iSorter];
 257                                         int cmp = sorter.Compare (elt1.Values [iSorter], elt2.Values [iSorter]);
 258                                         if (cmp != 0)
 259                                                 return cmp;
 260                                 }
 261                                 switch (elt1.Navigator.ComparePosition (elt2.Navigator)) {
 262                                 case XmlNodeOrder.Same:
 263                                         return 0;
 264                                 case XmlNodeOrder.After:
 265                                         return 1;
 266                                 default:
 267                                         return -1;
 268                                 }
 269                         }
 270
 271                         class XPathSorter
 272                         {
 273                                 readonly Expression _expr;
 274                                 readonly IComparer _cmp;
 275                                 readonly XmlDataType _type;
 276
 277                                 public XPathSorter (object expr, IComparer cmp)
 278                                 {
 279                                         _expr = ExpressionFromObject (expr);
 280                                         _cmp = cmp;
 281                                         _type = XmlDataType.Text;
 282                                 }
 283
 284                                 public XPathSorter (object expr, XmlSortOrder orderSort, XmlCaseOrder orderCase, string lang, XmlDataType dataType)
 285                                 {
 286                                         _expr = ExpressionFromObject (expr);
 287                                         _type = dataType;
 288                                         if (dataType == XmlDataType.Number)
 289                                                 _cmp = new XPathNumberComparer (orderSort);
 290                                         else
 291                                                 _cmp = new XPathTextComparer (orderSort, orderCase, lang);
 292                                 }
 293
 294                                 static Expression ExpressionFromObject (object expr)
 295                                 {
 296                                         if (expr is CompiledExpression)
 297                                                 return ((CompiledExpression) expr)._expr;
 298                                         if (expr is string)
 299                                                 return new XPathParser ().Compile ((string)expr);
 300
 301                                         throw new XPathException ("Invalid query object");
 302                                 }
 303
 304                                 public object Evaluate (BaseIterator iter)
 305                                 {
 306                                         if (_type == XmlDataType.Number)
 307                                                 return _expr.EvaluateNumber (iter);
 308                                         return _expr.EvaluateString (iter);
 309                                 }
 310
 311                                 public int Compare (object o1, object o2)
 312                                 {
 313                                         return _cmp.Compare (o1, o2);
 314                                 }
 315
 316                                 class XPathNumberComparer : IComparer
 317                                 {
 318                                         int _nMulSort;
 319
 320                                         public XPathNumberComparer (XmlSortOrder orderSort)
 321                                         {
 322                                                 _nMulSort = (orderSort == XmlSortOrder.Ascending) ? 1 : -1;
 323                                         }
 324
 325                                         int IComparer.Compare (object o1, object o2)
 326                                         {
 327                                                 double num1 = (double) o1;
 328                                                 double num2 = (double) o2;
 329                                                 if (num1 < num2)
 330                                                         return -_nMulSort;
 331                                                 if (num1 > num2)
 332                                                         return _nMulSort;
 333                                                 if (num1 == num2)
 334                                                         return 0;
 335                                                 if (double.IsNaN (num1))
 336                                                         return (double.IsNaN (num2)) ? 0 : -_nMulSort;
 337                                                 return _nMulSort;
 338                                         }
 339                                 }
 340
 341                                 class XPathTextComparer : IComparer
 342                                 {
 343                                         int _nMulSort;
 344                                         int _nMulCase;
 345                                         XmlCaseOrder _orderCase;
 346                                         CultureInfo _ci;
 347
 348                                         public XPathTextComparer (XmlSortOrder orderSort, XmlCaseOrder orderCase, string strLang)
 349                                         {
 350                                                 _orderCase = orderCase;
 351                                                 _nMulCase = (orderCase == XmlCaseOrder.UpperFirst) ? 1 : -1;
 352
 353                                                 _nMulSort = (orderSort == XmlSortOrder.Ascending) ? 1 : -1;
 354
 355                                                 if (strLang == null || strLang == "")
 356                                                         _ci = CultureInfo.CurrentCulture;       // TODO: defer until evaluation?
 357                                                 else
 358                                                         _ci = new CultureInfo (strLang);
 359                                         }
 360
 361                                         int IComparer.Compare (object o1, object o2)
 362                                         {
 363                                                 string str1 = (string) o1;
 364                                                 string str2 = (string) o2;
 365                                                 int cmp = String.Compare (str1, str2, true, _ci);
 366                                                 if (cmp != 0 || _orderCase == XmlCaseOrder.None)
 367                                                         return cmp * _nMulSort;
 368                                                 return _nMulSort * _nMulCase * String.Compare (str1, str2, false, _ci);
 369                                         }
 370                                 }
 371                         }
 372                 }
 373         }
 374
 375
 376         /// <summary>
 377         /// Summary description for Expression.
 378         /// </summary>
 379         internal abstract class Expression
 380         {
 381                 public Expression ()
 382                 {
 383                 }
 384                 public abstract XPathResultType ReturnType { get; }
 385                 public virtual XPathResultType GetReturnType (BaseIterator iter) { return ReturnType; }
 386
 387                 public virtual Expression Optimize ()
 388                 {
 389                         return this;
 390                 }
 391
 392                 public abstract object Evaluate (BaseIterator iter);
 393
 394                 public virtual BaseIterator EvaluateNodeSet (BaseIterator iter)
 395                 {
 396                         XPathResultType type = GetReturnType (iter);
 397                         switch (type) {
 398                         case XPathResultType.NodeSet:
 399                         case XPathResultType.Any:
 400                         case XPathResultType.Navigator: // FIXME: It may pass not-allowed use of RTF
 401                                 object o = Evaluate (iter);
 402                                 BaseIterator iterResult = o as BaseIterator;
 403                                 if (iterResult != null)
 404                                         return iterResult;
 405                                 XPathNavigator nav = o as XPathNavigator;
 406                                 if (nav != null)
 407                                         iterResult = nav.SelectChildren (XPathNodeType.All) as BaseIterator;
 408                                 if (iterResult != null)
 409                                         return iterResult;
 410                                 break;
 411                         }
 412                         throw new XPathException ("expected nodeset: "+ToString ());
 413                 }
 414
 415                 protected static XPathResultType GetReturnType (object obj)
 416                 {
 417                         if (obj is string)
 418                                 return XPathResultType.String;
 419                         if (obj is bool)
 420                                 return XPathResultType.Boolean;
 421                         if (obj is XPathNodeIterator)
 422                                 return XPathResultType.NodeSet;
 423                         if (obj is double || obj is int)
 424                                 return XPathResultType.Number;
 425                         if (obj is XPathNavigator)
 426                                 return XPathResultType.Navigator;
 427                         throw new XPathException ("invalid node type: "+obj.GetType ().ToString ());
 428                 }
 429
 430                 internal virtual XPathNodeType EvaluatedNodeType {
 431                         get { return XPathNodeType.All; }
 432                 }
 433
 434                 internal virtual bool IsPositional {
 435                         get { return false; }
 436                 }
 437
 438                 internal virtual bool Peer {
 439                         get { return false; }
 440                 }
 441
 442                 public virtual double EvaluateNumber (BaseIterator iter)
 443                 {
 444                         object result;
 445                         XPathResultType type = GetReturnType (iter);
 446                         if (type == XPathResultType.NodeSet)
 447                         {
 448                                 result = EvaluateString (iter);
 449                                 type = XPathResultType.String;
 450                         }
 451                         else
 452                                 result = Evaluate (iter);
 453
 454                         if (type == XPathResultType.Any)
 455                                 type = GetReturnType (result);
 456
 457                         switch (type)
 458                         {
 459                                 case XPathResultType.Number:
 460                                         return (double)result;
 461                                 case XPathResultType.Boolean:
 462                                         return ((bool) result) ? 1.0 : 0.0;
 463                                 case XPathResultType.NodeSet:
 464                                         return XPathFunctions.ToNumber (EvaluateString (iter));
 465                                 case XPathResultType.String:
 466                                         return XPathFunctions.ToNumber ((string) result);
 467                                 case XPathResultType.Navigator:
 468                                         return XPathFunctions.ToNumber (((XPathNavigator) (result)).Value);
 469                                 default:
 470                                         throw new XPathException ("invalid node type");
 471                         }
 472                 }
 473
 474                 public virtual string EvaluateString (BaseIterator iter)
 475                 {
 476                         object result = Evaluate (iter);
 477                         XPathResultType type = GetReturnType (iter);
 478                         if (type == XPathResultType.Any)
 479                                 type = GetReturnType (result);
 480                         switch (type)
 481                         {
 482                                 case XPathResultType.Number:
 483                                         double d = (double) result;
 484                                         // See XPath 1.0 section 4.2
 485                                         if (d == Double.NegativeInfinity)
 486                                                 return "-Infinity";
 487                                         if (d == Double.PositiveInfinity)
 488                                                 return "Infinity";
 489                                         return (string) XmlConvert.ToString (d);
 490                                 case XPathResultType.Boolean:
 491                                         return ((bool) result) ? "true" : "false";
 492                                 case XPathResultType.String:
 493                                         return (string) result;
 494                                 case XPathResultType.NodeSet:
 495                                 {
 496                                         BaseIterator iterResult = (BaseIterator) result;
 497                                         if (iterResult == null || !iterResult.MoveNext ())
 498                                                 return "";
 499                                         return iterResult.Current.Value;
 500                                 }
 501                                 case XPathResultType.Navigator:
 502                                         return ((XPathNavigator) result).Value;
 503                                 default:
 504                                         throw new XPathException ("invalid node type");
 505                         }
 506                 }
 507
 508                 public virtual bool EvaluateBoolean (BaseIterator iter)
 509                 {
 510                         object result = Evaluate (iter);
 511                         XPathResultType type = GetReturnType (iter);
 512                         if (type == XPathResultType.Any)
 513                                 type = GetReturnType (result);
 514                         switch (type)
 515                         {
 516                                 case XPathResultType.Number:
 517                                 {
 518                                         double num = Convert.ToDouble (result);
 519                                         return (num != 0.0 && num != -0.0 && !Double.IsNaN (num));
 520                                 }
 521                                 case XPathResultType.Boolean:
 522                                         return (bool) result;
 523                                 case XPathResultType.String:
 524                                         return ((string) result).Length != 0;
 525                                 case XPathResultType.NodeSet:
 526                                 {
 527                                         BaseIterator iterResult = (BaseIterator) result;
 528                                         return (iterResult != null && iterResult.MoveNext ());
 529                                 }
 530                                 case XPathResultType.Navigator:
 531                                         return ((string) ((XPathNavigator) result).Value).Length != 0;
 532                                 default:
 533                                         throw new XPathException ("invalid node type");
 534                         }
 535                 }
 536
 537                 public object EvaluateAs (BaseIterator iter, XPathResultType type)
 538                 {
 539                         switch (type)
 540                         {
 541                         case XPathResultType.Boolean:
 542                                 return EvaluateBoolean (iter);
 543                         case XPathResultType.NodeSet:
 544                                 return EvaluateNodeSet (iter);
 545                         case XPathResultType.String:
 546                                 return EvaluateString (iter);
 547                         case XPathResultType.Number:
 548                                 return EvaluateNumber (iter);
 549                         }
 550                         return Evaluate (iter);
 551                 }
 552
 553                 public virtual bool RequireSorting { get { return false; } }
 554         }
 555
 556         internal abstract class ExprBinary : Expression
 557         {
 558                 protected Expression _left, _right;
 559
 560                 public ExprBinary (Expression left, Expression right)
 561                 {
 562                         _left = left;
 563                         _right = right;
 564                 }
 565                 public override String ToString ()
 566                 {
 567                         return _left.ToString () + ' ' + Operator + ' ' + _right.ToString ();
 568                 }
 569                 protected abstract String Operator { get; }
 570
 571                 internal override XPathNodeType EvaluatedNodeType {
 572                         get {
 573                                 if (_left.EvaluatedNodeType == _right.EvaluatedNodeType)
 574                                         return _left.EvaluatedNodeType;
 575                                 else
 576                                         return XPathNodeType.All;
 577                         }
 578                 }
 579
 580                 internal override bool IsPositional {
 581                         get { return _left.IsPositional || _right.IsPositional; }
 582                 }
 583
 584                 internal override bool Peer {
 585                         get { return _left.Peer && _right.Peer; }
 586                 }
 587         }
 588
 589         internal abstract class ExprBoolean : ExprBinary
 590         {
 591                 public ExprBoolean (Expression left, Expression right) : base (left, right) {}
 592                 public override XPathResultType ReturnType { get { return XPathResultType.Boolean; }}
 593                 public override object Evaluate (BaseIterator iter)
 594                 {
 595                         return EvaluateBoolean (iter);
 596                 }
 597                 public override double EvaluateNumber (BaseIterator iter)
 598                 {
 599                         return EvaluateBoolean (iter) ? 1 : 0;
 600                 }
 601
 602                 public override string EvaluateString (BaseIterator iter)
 603                 {
 604                         return EvaluateBoolean (iter) ? "true" : "false";
 605                 }
 606         }
 607
 608         internal class ExprOR : ExprBoolean
 609         {
 610                 public ExprOR (Expression left, Expression right) : base (left, right) {}
 611                 protected override String Operator { get { return "or"; }}
 612                 public override bool EvaluateBoolean (BaseIterator iter)
 613                 {
 614                         if (_left.EvaluateBoolean (iter))
 615                                 return true;
 616                         return _right.EvaluateBoolean (iter);
 617                 }
 618         }
 619
 620         internal class ExprAND : ExprBoolean
 621         {
 622                 public ExprAND (Expression left, Expression right) : base (left, right) {}
 623                 protected override String Operator { get { return "and"; }}
 624                 public override bool EvaluateBoolean (BaseIterator iter)
 625                 {
 626                         if (!_left.EvaluateBoolean (iter))
 627                                 return false;
 628                         return _right.EvaluateBoolean (iter);
 629                 }
 630         }
 631
 632         internal abstract class EqualityExpr : ExprBoolean
 633         {
 634                 bool trueVal;
 635                 public EqualityExpr (Expression left, Expression right, bool trueVal) : base (left, right)
 636                 {
 637                         this.trueVal = trueVal;
 638                 }
 639
 640                 [MonoTODO ("Avoid extraneous evaluation")]
 641                 public override bool EvaluateBoolean (BaseIterator iter)
 642                 {
 643                         XPathResultType typeL = _left.GetReturnType (iter);
 644                         XPathResultType typeR = _right.GetReturnType (iter);
 645
 646                         // TODO: avoid double evaluations
 647                         if (typeL == XPathResultType.Any)
 648                                 typeL = GetReturnType (_left.Evaluate (iter));
 649                         if (typeR == XPathResultType.Any)
 650                                 typeR = GetReturnType (_right.Evaluate (iter));
 651
 652                         // Regard RTF as nodeset
 653                         if (typeL == XPathResultType.Navigator)
 654                                 typeL = XPathResultType.NodeSet;
 655                         if (typeR == XPathResultType.Navigator)
 656                                 typeR = XPathResultType.NodeSet;
 657
 658                         if (typeL == XPathResultType.NodeSet || typeR == XPathResultType.NodeSet)
 659                         {
 660                                 Expression left, right;
 661                                 if (typeL != XPathResultType.NodeSet)
 662                                 {
 663                                         left = _right;
 664                                         right = _left;
 665                                         XPathResultType typeTmp = typeL;
 666                                         typeL = typeR;
 667                                         typeR = typeTmp;
 668                                 }
 669                                 else
 670                                 {
 671                                         left = _left;
 672                                         right = _right;
 673                                 }
 674                                 if (typeR == XPathResultType.Boolean)
 675                                 {
 676                                         return left.EvaluateBoolean (iter) == right.EvaluateBoolean (iter) == trueVal;
 677                                 }
 678                                 else
 679                                 {
 680                                         BaseIterator iterL = left.EvaluateNodeSet (iter);
 681                                         if (typeR == XPathResultType.Number)
 682                                         {
 683                                                 double dR = right.EvaluateNumber (iter);
 684                                                 while (iterL.MoveNext ())
 685                                                         if (XPathFunctions.ToNumber (iterL.Current.Value) == dR == trueVal)
 686                                                                 return true;
 687                                         }
 688                                         else if (typeR == XPathResultType.String)
 689                                         {
 690                                                 string strR = right.EvaluateString (iter);
 691                                                 while (iterL.MoveNext ())
 692                                                         if (iterL.Current.Value == strR == trueVal)
 693                                                                 return true;
 694                                         }
 695                                         else if (typeR == XPathResultType.NodeSet)
 696                                         {
 697                                                 BaseIterator iterR = right.EvaluateNodeSet (iter);
 698                                                 ArrayList rgNodesL = new ArrayList ();
 699                                                 while (iterL.MoveNext ())
 700                                                         rgNodesL.Add (XPathFunctions.ToString (iterL.Current.Value));
 701                                                 while (iterR.MoveNext ())
 702                                                 {
 703                                                         string strR = XPathFunctions.ToString (iterR.Current.Value);
 704                                                         for (int l = 0; l < rgNodesL.Count; l++)
 705                                                                 if ((strR == (string) rgNodesL [l]) == trueVal)
 706                                                                         return true;
 707                                                 }
 708                                         }
 709                                         return false;
 710                                 }
 711                         }
 712                         else if (typeL == XPathResultType.Boolean || typeR == XPathResultType.Boolean)
 713                                 return _left.EvaluateBoolean (iter) == _right.EvaluateBoolean (iter) == trueVal;
 714                         else if (typeL == XPathResultType.Number || typeR == XPathResultType.Number)
 715                                 return _left.EvaluateNumber (iter) == _right.EvaluateNumber (iter) == trueVal;
 716                         else
 717                                 return _left.EvaluateString (iter) == _right.EvaluateString (iter) == trueVal;
 718                 }
 719         }
 720
 721         internal class ExprEQ : EqualityExpr
 722         {
 723                 public ExprEQ (Expression left, Expression right) : base (left, right, true) {}
 724                 protected override String Operator { get { return "="; }}
 725         }
 726
 727         internal class ExprNE : EqualityExpr
 728         {
 729                 public ExprNE (Expression left, Expression right) : base (left, right, false) {}
 730                 protected override String Operator { get { return "!="; }}
 731         }
 732
 733         internal abstract class RelationalExpr : ExprBoolean
 734         {
 735                 public RelationalExpr (Expression left, Expression right) : base (left, right) {}
 736                 [MonoTODO ("Avoid extraneous evaluation.")]
 737                 public override bool EvaluateBoolean (BaseIterator iter)
 738                 {
 739                         XPathResultType typeL = _left.GetReturnType (iter);
 740                         XPathResultType typeR = _right.GetReturnType (iter);
 741
 742                         if (typeL == XPathResultType.Any)
 743                                 typeL = GetReturnType (_left.Evaluate (iter));
 744                         if (typeR == XPathResultType.Any)
 745                                 typeR = GetReturnType (_right.Evaluate (iter));
 746
 747                         // Regard RTF as nodeset
 748                         if (typeL == XPathResultType.Navigator)
 749                                 typeL = XPathResultType.NodeSet;
 750                         if (typeR == XPathResultType.Navigator)
 751                                 typeR = XPathResultType.NodeSet;
 752
 753                         if (typeL == XPathResultType.NodeSet || typeR == XPathResultType.NodeSet)
 754                         {
 755                                 bool fReverse = false;
 756                                 Expression left, right;
 757                                 if (typeL != XPathResultType.NodeSet)
 758                                 {
 759                                         fReverse = true;
 760                                         left = _right;
 761                                         right = _left;
 762                                         XPathResultType typeTmp = typeL;
 763                                         typeL = typeR;
 764                                         typeR = typeTmp;
 765                                 }
 766                                 else
 767                                 {
 768                                         left = _left;
 769                                         right = _right;
 770                                 }
 771                                 if (typeR == XPathResultType.Boolean)
 772                                 {
 773                                         bool fL = left.EvaluateBoolean (iter);
 774                                         bool fR = right.EvaluateBoolean (iter);
 775                                         return Compare (Convert.ToDouble (fL), Convert.ToDouble (fR), fReverse);
 776                                 }
 777                                 else
 778                                 {
 779                                         BaseIterator iterL = left.EvaluateNodeSet (iter);
 780                                         if (typeR == XPathResultType.Number || typeR == XPathResultType.String)
 781                                         {
 782                                                 double dR = right.EvaluateNumber (iter);
 783                                                 while (iterL.MoveNext ())
 784                                                         if (Compare (XPathFunctions.ToNumber (iterL.Current.Value), dR, fReverse))
 785                                                                 return true;
 786                                         }
 787                                         else if (typeR == XPathResultType.NodeSet)
 788                                         {
 789                                                 BaseIterator iterR = right.EvaluateNodeSet (iter);
 790                                                 ArrayList rgNodesL = new ArrayList ();
 791                                                 while (iterL.MoveNext ())
 792                                                         rgNodesL.Add (XPathFunctions.ToNumber (iterL.Current.Value));
 793                                                 while (iterR.MoveNext ())
 794                                                 {
 795                                                         double numR = XPathFunctions.ToNumber (iterR.Current.Value);
 796                                                         for (int l = 0; l < rgNodesL.Count; l++)
 797                                                                 if (Compare ((double) rgNodesL [l], numR))
 798                                                                         return true;
 799                                                 }
 800                                         }
 801                                         return false;
 802                                 }
 803                         }
 804                         else
 805                                 return Compare (_left.EvaluateNumber (iter), _right.EvaluateNumber (iter));
 806                 }
 807                 public abstract bool Compare (double arg1, double arg2);
 808                 public bool Compare (double arg1, double arg2, bool fReverse)
 809                 {
 810                         if (fReverse)
 811                                 return Compare (arg2, arg1);
 812                         else
 813                                 return Compare (arg1, arg2);
 814                 }
 815         }
 816
 817         internal class ExprGT : RelationalExpr
 818         {
 819                 public ExprGT (Expression left, Expression right) : base (left, right) {}
 820                 protected override String Operator { get { return ">"; }}
 821                 public override bool Compare (double arg1, double arg2)
 822                 {
 823                         return arg1 > arg2;
 824                 }
 825         }
 826
 827         internal class ExprGE : RelationalExpr
 828         {
 829                 public ExprGE (Expression left, Expression right) : base (left, right) {}
 830                 protected override String Operator { get { return ">="; }}
 831                 public override bool Compare (double arg1, double arg2)
 832                 {
 833                         return arg1 >= arg2;
 834                 }
 835         }
 836
 837         internal class ExprLT : RelationalExpr
 838         {
 839                 public ExprLT (Expression left, Expression right) : base (left, right) {}
 840                 protected override String Operator { get { return "<"; }}
 841                 public override bool Compare (double arg1, double arg2)
 842                 {
 843                         return arg1 < arg2;
 844                 }
 845         }
 846
 847         internal class ExprLE : RelationalExpr
 848         {
 849                 public ExprLE (Expression left, Expression right) : base (left, right) {}
 850                 protected override String Operator { get { return "<="; }}
 851                 public override bool Compare (double arg1, double arg2)
 852                 {
 853                         return arg1 <= arg2;
 854                 }
 855         }
 856
 857         internal abstract class ExprNumeric : ExprBinary
 858         {
 859                 public ExprNumeric (Expression left, Expression right) : base (left, right) {}
 860                 public override XPathResultType ReturnType { get { return XPathResultType.Number; }}
 861
 862                 public override object Evaluate (BaseIterator iter)
 863                 {
 864                         return EvaluateNumber (iter);
 865                 }
 866         }
 867
 868         internal class ExprPLUS : ExprNumeric
 869         {
 870                 public ExprPLUS (Expression left, Expression right) : base (left, right) {}
 871                 protected override String Operator { get { return "+"; }}
 872                 public override double EvaluateNumber (BaseIterator iter)
 873                 {
 874                         return _left.EvaluateNumber (iter) + _right.EvaluateNumber (iter);
 875                 }
 876         }
 877
 878         internal class ExprMINUS : ExprNumeric
 879         {
 880                 public ExprMINUS (Expression left, Expression right) : base (left, right) {}
 881                 protected override String Operator { get { return "-"; }}
 882                 public override double EvaluateNumber (BaseIterator iter)
 883                 {
 884                         return _left.EvaluateNumber (iter) - _right.EvaluateNumber (iter);
 885                 }
 886         }
 887
 888         internal class ExprMULT : ExprNumeric
 889         {
 890                 public ExprMULT (Expression left, Expression right) : base (left, right) {}
 891                 protected override String Operator { get { return "*"; }}
 892                 public override double EvaluateNumber (BaseIterator iter)
 893                 {
 894                         return _left.EvaluateNumber (iter) * _right.EvaluateNumber (iter);
 895                 }
 896         }
 897
 898         internal class ExprDIV : ExprNumeric
 899         {
 900                 public ExprDIV (Expression left, Expression right) : base (left, right) {}
 901                 protected override String Operator { get { return " div "; }}
 902                 public override double EvaluateNumber (BaseIterator iter)
 903                 {
 904                         return _left.EvaluateNumber (iter) / _right.EvaluateNumber (iter);
 905                 }
 906         }
 907
 908         internal class ExprMOD : ExprNumeric
 909         {
 910                 public ExprMOD (Expression left, Expression right) : base (left, right) {}
 911                 protected override String Operator { get { return "%"; }}
 912
 913                 public override double EvaluateNumber (BaseIterator iter)
 914                 {
 915                         return _left.EvaluateNumber (iter) % _right.EvaluateNumber (iter);
 916                 }
 917         }
 918
 919         internal class ExprNEG : Expression
 920         {
 921                 Expression _expr;
 922                 public ExprNEG (Expression expr)
 923                 {
 924                         _expr = expr;
 925                 }
 926                 public override String ToString () { return "- " + _expr.ToString (); }
 927                 public override XPathResultType ReturnType { get { return XPathResultType.Number; }}
 928                 public override object Evaluate (BaseIterator iter)
 929                 {
 930                         return - _expr.EvaluateNumber (iter);
 931                 }
 932
 933                 public override double EvaluateNumber (BaseIterator iter)
 934                 {
 935                         return - _expr.EvaluateNumber (iter);
 936                 }
 937
 938                 internal override bool IsPositional {
 939                         get { return _expr.IsPositional; }
 940                 }
 941         }
 942
 943
 944         internal abstract class NodeSet : Expression
 945         {
 946                 public override XPathResultType ReturnType { get { return XPathResultType.NodeSet; }}
 947
 948                 internal abstract bool Subtree { get; }
 949         }
 950
 951         internal class ExprUNION : NodeSet
 952         {
 953                 internal readonly Expression left, right;
 954                 public ExprUNION (Expression left, Expression right)
 955                 {
 956                         this.left = left;
 957                         this.right = right;
 958                 }
 959                 public override String ToString () { return left.ToString ()+ " | " + right.ToString (); }
 960                 public override object Evaluate (BaseIterator iter)
 961                 {
 962                         BaseIterator iterLeft = left.EvaluateNodeSet (iter);
 963                         BaseIterator iterRight = right.EvaluateNodeSet (iter);
 964                         return new UnionIterator (iter, iterLeft, iterRight);
 965                 }
 966
 967                 internal override XPathNodeType EvaluatedNodeType {
 968                         get { return left.EvaluatedNodeType == right.EvaluatedNodeType ? left.EvaluatedNodeType : XPathNodeType.All; }
 969                 }
 970
 971                 internal override bool IsPositional {
 972                         get { return left.IsPositional || right.IsPositional; }
 973                 }
 974
 975                 internal override bool Peer {
 976                         get { return left.Peer && right.Peer; }
 977                 }
 978
 979                 internal override bool Subtree {
 980                         get {
 981                                 NodeSet nl = left as NodeSet;
 982                                 NodeSet nr = right as NodeSet;
 983                                 return nl != null && nr != null && nl.Subtree && nr.Subtree;
 984                         }
 985                 }
 986         }
 987
 988         internal class ExprSLASH : NodeSet
 989         {
 990                 public readonly Expression left;
 991                 public readonly NodeSet right;
 992                 public ExprSLASH (Expression left, NodeSet right)
 993                 {
 994                         this.left = left;
 995                         this.right = right;
 996                 }
 997                 public override String ToString () { return left.ToString ()+ "/" + right.ToString (); }
 998                 public override object Evaluate (BaseIterator iter)
 999                 {
1000                         BaseIterator iterLeft = left.EvaluateNodeSet (iter);
1001                         if (left.Peer && right.Subtree && !RequireSorting)
1002                                 return new SimpleSlashIterator (iterLeft, right);
1003                         return new SlashIterator (iterLeft, right, RequireSorting);
1004                 }
1005
1006                 public override bool RequireSorting { get { return left.RequireSorting || right.RequireSorting; } }
1007
1008                 internal override XPathNodeType EvaluatedNodeType {
1009                         get { return right.EvaluatedNodeType; }
1010                 }
1011
1012                 internal override bool IsPositional {
1013                         get { return left.IsPositional || right.IsPositional; }
1014                 }
1015
1016                 internal override bool Peer {
1017                         get { return left.Peer && right.Peer; }
1018                 }
1019
1020                 internal override bool Subtree {
1021                         get {
1022                                 NodeSet n = left as NodeSet;
1023                                 return n != null && n.Subtree && right.Subtree;
1024                         }
1025                 }
1026         }
1027
1028         internal class ExprSLASH2 : NodeSet {
1029                 public readonly Expression left;
1030                 public readonly NodeSet right;
1031
1032                 static NodeTest DescendantOrSelfStar = new NodeTypeTest (Axes.DescendantOrSelf, XPathNodeType.All);
1033
1034                 public ExprSLASH2 (Expression left, NodeSet right)
1035                 {
1036                         this.left = left;
1037                         this.right = right;
1038                 }
1039                 public override String ToString () { return left.ToString ()+ "//" + right.ToString (); }
1040                 public override object Evaluate (BaseIterator iter)
1041                 {
1042                         return new SlashIterator (
1043                                 new SlashIterator (
1044                                         left.EvaluateNodeSet (iter),
1045                                         DescendantOrSelfStar,
1046                                         left.RequireSorting || DescendantOrSelfStar.RequireSorting
1047                                 ),
1048                                 right,
1049                                 DescendantOrSelfStar.RequireSorting || right.RequireSorting
1050                         );
1051                 }
1052
1053                 public override bool RequireSorting { get { return left.RequireSorting || right.RequireSorting; } }
1054
1055                 internal override XPathNodeType EvaluatedNodeType {
1056                         get { return right.EvaluatedNodeType; }
1057                 }
1058
1059                 internal override bool IsPositional {
1060                         get { return left.IsPositional || right.IsPositional; }
1061                 }
1062
1063                 internal override bool Peer {
1064                         get { return false; }
1065                 }
1066
1067                 internal override bool Subtree {
1068                         get {
1069                                 NodeSet n = left as NodeSet;
1070                                 return n != null && n.Subtree && right.Subtree;
1071                         }
1072                 }
1073         }
1074
1075         internal class ExprRoot : NodeSet
1076         {
1077                 public override String ToString () { return ""; }
1078                 public override object Evaluate (BaseIterator iter)
1079                 {
1080                         XPathNavigator navRoot = iter.Current.Clone ();
1081                         navRoot.MoveToRoot ();
1082                         return new SelfIterator (navRoot, iter.NamespaceManager);
1083                 }
1084
1085                 internal override XPathNodeType EvaluatedNodeType {
1086                         get { return XPathNodeType.Root; }
1087                 }
1088
1089                 internal override bool Peer {
1090                         get { return true; }
1091                 }
1092
1093                 internal override bool Subtree {
1094                         get { return false; }
1095                 }
1096         }
1097
1098         internal enum Axes
1099         {
1100                 Ancestor,
1101                 AncestorOrSelf,
1102                 Attribute,
1103                 Child,
1104                 Descendant,
1105                 DescendantOrSelf,
1106                 Following,
1107                 FollowingSibling,
1108                 Namespace,
1109                 Parent,
1110                 Preceding,
1111                 PrecedingSibling,
1112                 Self,
1113         }
1114
1115         internal class AxisSpecifier
1116         {
1117                 protected Axes _axis;
1118                 public AxisSpecifier (Axes axis)
1119                 {
1120                         _axis = axis;
1121                 }
1122                 public XPathNodeType NodeType
1123                 {
1124                         get
1125                         {
1126                                 switch (_axis)
1127                                 {
1128                                 case Axes.Namespace:
1129                                         return XPathNodeType.Namespace;
1130                                 case Axes.Attribute:
1131                                         return XPathNodeType.Attribute;
1132                                 default:
1133                                         return XPathNodeType.Element;
1134                                 }
1135                         }
1136                 }
1137                 public override string ToString ()
1138                 {
1139                         switch (_axis)
1140                         {
1141                                 case Axes.Ancestor:
1142                                         return "ancestor";
1143                                 case Axes.AncestorOrSelf:
1144                                         return "ancestor-or-self";
1145                                 case Axes.Attribute:
1146                                         return "attribute";
1147                                 case Axes.Child:
1148                                         return "child";
1149                                 case Axes.Descendant:
1150                                         return "descendant";
1151                                 case Axes.DescendantOrSelf:
1152                                         return "descendant-or-self";
1153                                 case Axes.Following:
1154                                         return "following";
1155                                 case Axes.FollowingSibling:
1156                                         return "following-sibling";
1157                                 case Axes.Namespace:
1158                                         return "namespace";
1159                                 case Axes.Parent:
1160                                         return "parent";
1161                                 case Axes.Preceding:
1162                                         return "preceeding";
1163                                 case Axes.PrecedingSibling:
1164                                         return "preceeding-sibling";
1165                                 case Axes.Self:
1166                                         return "self";
1167                                 default:
1168                                         throw new IndexOutOfRangeException ();
1169                         }
1170                 }
1171                 public Axes Axis { get { return _axis; }}
1172                 public virtual SimpleIterator Evaluate (BaseIterator iter)
1173                 {
1174                         switch (_axis)
1175                         {
1176                                 case Axes.Ancestor:
1177                                         return new AncestorIterator (iter);
1178                                 case Axes.AncestorOrSelf:
1179                                         return new AncestorOrSelfIterator (iter);
1180                                 case Axes.Attribute:
1181                                         return new AttributeIterator (iter);
1182                                 case Axes.Child:
1183                                         return new ChildIterator (iter);
1184                                 case Axes.Descendant:
1185                                         return new DescendantIterator (iter);
1186                                 case Axes.DescendantOrSelf:
1187                                         return new DescendantOrSelfIterator (iter);
1188                                 case Axes.Following:
1189                                         return new FollowingIterator (iter);
1190                                 case Axes.FollowingSibling:
1191                                         return new FollowingSiblingIterator (iter);
1192                                 case Axes.Namespace:
1193                                         return new NamespaceIterator (iter);
1194                                 case Axes.Parent:
1195                                         return new ParentIterator (iter);
1196                                 case Axes.Preceding:
1197                                         return new PrecedingIterator (iter);
1198                                 case Axes.PrecedingSibling:
1199                                         return new PrecedingSiblingIterator (iter);
1200                                 case Axes.Self:
1201                                         return new SelfIterator (iter);
1202                                 default:
1203                                         throw new IndexOutOfRangeException ();
1204                         }
1205                 }
1206         }
1207
1208         internal abstract class NodeTest : NodeSet
1209         {
1210                 protected AxisSpecifier _axis;
1211                 public NodeTest (Axes axis)
1212                 {
1213                         _axis = new AxisSpecifier (axis);
1214                 }
1215                 public abstract bool Match (NSResolver nsm, XPathNavigator nav);
1216                 public AxisSpecifier Axis { get { return _axis; }}
1217                 public override object Evaluate (BaseIterator iter)
1218                 {
1219                         SimpleIterator iterAxis = _axis.Evaluate (iter);
1220                         return new AxisIterator (iterAxis, this);
1221                 }
1222
1223                 public abstract void GetInfo (out string name, out string ns, out XPathNodeType nodetype, NSResolver nsm);
1224
1225                 public override bool RequireSorting {
1226                         get {
1227                                 switch (_axis.Axis) {
1228                                 case Axes.Ancestor:
1229                                 case Axes.AncestorOrSelf:
1230                                 case Axes.Preceding:
1231                                 case Axes.PrecedingSibling:
1232                                 case Axes.Attribute:
1233                                 case Axes.Namespace:
1234                                         return true;
1235                                 default:
1236                                         return false;
1237                                 }
1238                         }
1239
1240                 }
1241
1242                 internal override bool Peer {
1243                         get {
1244                                 switch (_axis.Axis) {
1245                                 case Axes.Ancestor:
1246                                 case Axes.AncestorOrSelf:
1247                                 case Axes.DescendantOrSelf:
1248                                 case Axes.Descendant:
1249                                 case Axes.Preceding:
1250                                 case Axes.Following:
1251                                         return false;
1252                                 default:
1253                                         return true;
1254                                 }
1255                         }
1256                 }
1257
1258                 internal override bool Subtree {
1259                         get {
1260                                 switch (_axis.Axis) {
1261                                 case Axes.Parent:
1262                                 case Axes.Ancestor:
1263                                 case Axes.AncestorOrSelf:
1264                                 case Axes.Preceding:
1265                                 case Axes.Following:
1266                                         return false;
1267                                 default:
1268                                         return true;
1269                                 }
1270                         }
1271
1272                 }
1273
1274                 internal override XPathNodeType EvaluatedNodeType {
1275                         get { return _axis.NodeType; }
1276                 }
1277         }
1278
1279         internal class NodeTypeTest : NodeTest
1280         {
1281                 public readonly XPathNodeType type;
1282                 protected String _param;
1283                 public NodeTypeTest (Axes axis) : base (axis)
1284                 {
1285                         this.type = _axis.NodeType;
1286                 }
1287                 public NodeTypeTest (Axes axis, XPathNodeType type) : base (axis)
1288                 {
1289                         this.type = type;
1290                 }
1291                 [MonoTODO ("Better description.")]
1292                 public NodeTypeTest (Axes axis, XPathNodeType type, String param) : base (axis)
1293                 {
1294                         this.type = type;
1295                         _param = param;
1296                         if (param != null && type != XPathNodeType.ProcessingInstruction)
1297                                 throw new XPathException ("No argument allowed for "+ToString (type)+"() test");        // TODO: better description
1298                 }
1299
1300                 public override String ToString ()
1301                 {
1302                         String strType = ToString (type);
1303                         if (type == XPathNodeType.ProcessingInstruction && _param != null)
1304                                 strType += "('" + _param + "')";
1305                         else
1306                                 strType += "()";
1307
1308                         return _axis.ToString () + "::" + strType;
1309                 }
1310
1311                 private static String ToString (XPathNodeType type)
1312                 {
1313                         switch (type)
1314                         {
1315                                 case XPathNodeType.Comment:
1316                                         return "comment";
1317                                 case XPathNodeType.Text:
1318                                         return "text";
1319                                 case XPathNodeType.ProcessingInstruction:
1320                                         return "processing-instruction";
1321                                 case XPathNodeType.All:
1322                                 case XPathNodeType.Attribute:
1323                                 case XPathNodeType.Element:
1324                                 case XPathNodeType.Namespace:
1325                                         return "node";
1326                                 default:
1327                                         return "node-type [" + type.ToString () + "]";
1328                         }
1329                 }
1330
1331                 public override bool Match (NSResolver nsm, XPathNavigator nav)
1332                 {
1333                         XPathNodeType nodeType = nav.NodeType;
1334                         switch (type)
1335                         {
1336                                 case XPathNodeType.All:
1337                                         return true;
1338
1339                                 case XPathNodeType.ProcessingInstruction:
1340                                         if (nodeType != XPathNodeType.ProcessingInstruction)
1341                                                 return false;
1342                                         if (_param != null && nav.Name != _param)
1343                                                 return false;
1344                                         return true;
1345
1346                                 case XPathNodeType.Text:
1347                                         if (nodeType == XPathNodeType.SignificantWhitespace)
1348                                                 return true;
1349                                         goto default;
1350                                 default:
1351                                         return type == nodeType;
1352                         }
1353                 }
1354
1355                 public override void GetInfo (out string name, out string ns, out XPathNodeType nodetype, NSResolver nsm)
1356                 {
1357                         name = _param;
1358                         ns = null;
1359                         nodetype = type;
1360                 }
1361         }
1362
1363         internal class NodeNameTest : NodeTest
1364         {
1365                 protected XmlQualifiedName _name;
1366                 protected readonly bool resolvedName = false;
1367                 public NodeNameTest (Axes axis, XmlQualifiedName name, IStaticXsltContext ctx) : base (axis)
1368                 {
1369                         if (ctx != null) {
1370                                 name = ctx.LookupQName (name.ToString ());
1371                                 resolvedName = true;
1372                         }
1373                         _name = name;
1374                 }
1375
1376                 public NodeNameTest (Axes axis, XmlQualifiedName name, bool resolvedName) : base (axis)
1377                 {
1378                         _name = name;
1379                         resolvedName = resolvedName;
1380                 }
1381                 public override String ToString () { return _axis.ToString () + "::" + _name.ToString (); }
1382
1383                 public XmlQualifiedName Name { get { return _name; } }
1384
1385                 public override bool Match (NSResolver nsm, XPathNavigator nav)
1386                 {
1387                         // must be the correct node type
1388                         if (nav.NodeType != _axis.NodeType)
1389                                 return false;
1390
1391                         if (_name.Name != "")
1392                         {
1393                                 // test the local part of the name first
1394                                 if (_name.Name != nav.LocalName)
1395                                         return false;
1396                         }
1397
1398                         // get the prefix for the given name
1399                         String strURI1 = "";
1400                         if (nsm != null && _name.Namespace != "")
1401                         {
1402                                 if (resolvedName)
1403                                         strURI1 = _name.Namespace;
1404                                 else
1405                                         strURI1 = nsm.LookupNamespace (_name.Namespace, false);
1406                                 if (strURI1 == null)
1407                                         throw new XPathException ("Invalid namespace prefix: "+_name.Namespace);
1408                         }
1409
1410                         // test the prefixes
1411                         return strURI1 == nav.NamespaceURI;
1412                 }
1413
1414                 public override void GetInfo (out string name, out string ns, out XPathNodeType nodetype, NSResolver nsm)
1415                 {
1416                         // must be the correct node type
1417                         nodetype = _axis.NodeType;
1418
1419                         if (_name.Name != "")
1420                                 name = _name.Name;
1421                         else
1422                                 name = null;
1423                         ns = "";
1424                         if (nsm != null && _name.Namespace != "") {
1425                                 if (resolvedName)
1426                                         ns = _name.Namespace;
1427                                 else
1428                                         ns = nsm.LookupNamespace (_name.Namespace, false);      // TODO: check to see if this returns null or ""
1429                                 if (ns == null)
1430                                         throw new XPathException ("Invalid namespace prefix: "+_name.Namespace);
1431                         }
1432                 }
1433         }
1434
1435         internal class ExprFilter : NodeSet
1436         {
1437                 public readonly Expression expr, pred;
1438
1439                 public ExprFilter (Expression expr, Expression pred)
1440                 {
1441                         this.expr = expr;
1442                         this.pred = pred;
1443                 }
1444
1445                 internal Expression LeftHandSide {get{return expr;}}
1446                 public override String ToString () { return "(" + expr.ToString () + ")[" + pred.ToString () + "]"; }
1447                 public override object Evaluate (BaseIterator iter)
1448                 {
1449                         BaseIterator iterExpr = expr.EvaluateNodeSet (iter);
1450                         return new PredicateIterator (iterExpr, pred);
1451                 }
1452
1453                 internal override XPathNodeType EvaluatedNodeType {
1454                         get { return expr.EvaluatedNodeType; }
1455                 }
1456
1457                 internal override bool IsPositional {
1458                         get {
1459                                 if (pred.ReturnType == XPathResultType.Number)
1460                                         return true;
1461                                 return expr.IsPositional || pred.IsPositional;
1462                         }
1463                 }
1464
1465                 internal override bool Peer {
1466                         get { return expr.Peer && pred.Peer; }
1467                 }
1468
1469                 internal override bool Subtree {
1470                         get {
1471                                 NodeSet n = expr as NodeSet;
1472                                 return n != null && n.Subtree;
1473                         }
1474                 }
1475         }
1476
1477         internal class ExprNumber : Expression
1478         {
1479                 protected double _value;
1480                 public ExprNumber (double value)
1481                 {
1482                         _value = value;
1483                 }
1484                 public override String ToString () { return _value.ToString (); }
1485                 public override XPathResultType ReturnType { get { return XPathResultType.Number; }}
1486                 public override object Evaluate (BaseIterator iter)
1487                 {
1488                         return _value;
1489                 }
1490
1491                 public override double EvaluateNumber (BaseIterator iter)
1492                 {
1493                         return _value;
1494                 }
1495
1496                 internal override bool IsPositional {
1497                         get { return false; }
1498                 }
1499         }
1500
1501         internal class ExprLiteral : Expression
1502         {
1503                 protected String _value;
1504                 public ExprLiteral (String value)
1505                 {
1506                         _value = value;
1507                 }
1508                 public string Value { get { return _value; } }
1509                 public override String ToString () { return "'" + _value + "'"; }
1510                 public override XPathResultType ReturnType { get { return XPathResultType.String; }}
1511                 public override object Evaluate (BaseIterator iter)
1512                 {
1513                         return _value;
1514                 }
1515
1516                 public override string EvaluateString (BaseIterator iter)
1517                 {
1518                         return _value;
1519                 }
1520         }
1521
1522         internal class ExprVariable : Expression
1523         {
1524                 protected XmlQualifiedName _name;
1525                 protected bool resolvedName = false;
1526                 public ExprVariable (XmlQualifiedName name, IStaticXsltContext ctx)
1527                 {
1528                         if (ctx != null) {
1529                                 name = ctx.LookupQName (name.ToString ());
1530                                 resolvedName = true;
1531                         }
1532
1533                         _name = name;
1534                 }
1535                 public override String ToString () { return "$" + _name.ToString (); }
1536                 public override XPathResultType ReturnType { get { return XPathResultType.Any; }}
1537                 public override XPathResultType GetReturnType (BaseIterator iter)
1538                 {
1539                         return XPathResultType.Any;
1540                 }
1541
1542                 public override object Evaluate (BaseIterator iter)
1543                 {
1544                         IXsltContextVariable var = null;
1545
1546                         XsltContext context = iter.NamespaceManager as XsltContext;
1547                         if (context != null) {
1548                                 if (resolvedName)
1549                                         var = context.ResolveVariable (_name);
1550                                 else
1551                                         var = context.ResolveVariable (new XmlQualifiedName (_name.Name, _name.Namespace));
1552                         }
1553
1554                         if (var == null)
1555                                 throw new XPathException ("variable "+_name.ToString ()+" not found");
1556                         object objResult = var.Evaluate (context);
1557                         XPathNodeIterator iterResult = objResult as XPathNodeIterator;
1558                         if (iterResult != null)
1559                                 return iterResult is BaseIterator ? iterResult : new WrapperIterator (iterResult, iter.NamespaceManager);
1560                         return objResult;
1561                 }
1562
1563                 internal override bool Peer {
1564                         get { return false; }
1565                 }
1566         }
1567
1568         internal class ExprParens : Expression
1569         {
1570                 protected Expression _expr;
1571                 public ExprParens (Expression expr)
1572                 {
1573                         _expr = expr;
1574                 }
1575
1576                 public override Expression Optimize ()
1577                 {
1578                         return _expr;
1579                 }
1580
1581                 public override String ToString () { return "(" + _expr.ToString () + ")"; }
1582                 public override XPathResultType ReturnType { get { return _expr.ReturnType; }}
1583                 public override object Evaluate (BaseIterator iter)
1584                 {
1585                         object o = (_expr.Evaluate (iter));
1586                         BaseIterator predBase = o as BaseIterator;
1587                         if (predBase != null)
1588                                 return new ParensIterator (predBase);
1589                         else
1590                                 return o;
1591                 }
1592
1593                 internal override XPathNodeType EvaluatedNodeType {
1594                         get { return _expr.EvaluatedNodeType; }
1595                 }
1596
1597                 internal override bool IsPositional {
1598                         get { return _expr.IsPositional; }
1599                 }
1600
1601                 internal override bool Peer {
1602                         get { return _expr.Peer; }
1603                 }
1604         }
1605
1606         internal class FunctionArguments
1607         {
1608                 protected Expression _arg;
1609                 protected FunctionArguments _tail;
1610                 public FunctionArguments (Expression arg, FunctionArguments tail)
1611                 {
1612                         _arg = arg;
1613                         _tail = tail;
1614                 }
1615                 public Expression Arg
1616                 {
1617                         get { return _arg; }
1618                 }
1619                 public FunctionArguments Tail
1620                 {
1621                         get { return _tail; }
1622                 }
1623
1624                 public void ToArrayList (ArrayList a)
1625                 {
1626                         FunctionArguments cur = this;
1627
1628                         do {
1629                                 a.Add (cur._arg);
1630                                 cur = cur._tail;
1631                         } while (cur != null);
1632
1633                 }
1634         }
1635
1636         internal class ExprFunctionCall : Expression
1637         {
1638                 protected readonly XmlQualifiedName _name;
1639                 protected readonly bool resolvedName = false;
1640                 protected readonly ArrayList _args = new ArrayList ();
1641                 public ExprFunctionCall (XmlQualifiedName name, FunctionArguments args, IStaticXsltContext ctx)
1642                 {
1643                         if (ctx != null) {
1644                                 name = ctx.LookupQName (name.ToString ());
1645                                 resolvedName = true;
1646                         }
1647
1648                         _name = name;
1649                         if (args != null)
1650                                 args.ToArrayList (_args);
1651                 }
1652
1653                 public static Expression Factory (XmlQualifiedName name, FunctionArguments args, IStaticXsltContext ctx)
1654                 {
1655                         if (name.Namespace != null && name.Namespace != "")
1656                                 return new ExprFunctionCall (name, args, ctx);
1657
1658                         switch (name.Name) {
1659                                 case "last": return new XPathFunctionLast (args);
1660                                 case "position": return new XPathFunctionPosition (args);
1661                                 case "count": return new XPathFunctionCount (args);
1662                                 case "id": return new XPathFunctionId (args);
1663                                 case "local-name": return new XPathFunctionLocalName (args);
1664                                 case "namespace-uri": return new XPathFunctionNamespaceUri (args);
1665                                 case "name": return new XPathFunctionName (args);
1666                                 case "string": return new XPathFunctionString (args);
1667                                 case "concat": return new XPathFunctionConcat (args);
1668                                 case "starts-with": return new XPathFunctionStartsWith (args);
1669                                 case "contains": return new XPathFunctionContains (args);
1670                                 case "substring-before": return new XPathFunctionSubstringBefore (args);
1671                                 case "substring-after": return new XPathFunctionSubstringAfter (args);
1672                                 case "substring": return new XPathFunctionSubstring (args);
1673                                 case "string-length": return new XPathFunctionStringLength (args);
1674                                 case "normalize-space": return new XPathFunctionNormalizeSpace (args);
1675                                 case "translate": return new XPathFunctionTranslate (args);
1676                                 case "boolean": return new XPathFunctionBoolean (args);
1677                                 case "not": return new XPathFunctionNot (args);
1678                                 case "true": return new XPathFunctionTrue (args);
1679                                 case "false": return new XPathFunctionFalse (args);
1680                                 case "lang": return new XPathFunctionLang (args);
1681                                 case "number": return new XPathFunctionNumber (args);
1682                                 case "sum": return new XPathFunctionSum (args);
1683                                 case "floor": return new XPathFunctionFloor (args);
1684                                 case "ceiling": return new XPathFunctionCeil (args);
1685                                 case "round": return new XPathFunctionRound (args);
1686                         }
1687                         return new ExprFunctionCall (name, args, ctx);
1688                 }
1689
1690                 public override String ToString ()
1691                 {
1692                         String strArgs = "";
1693                         for (int i = 0; i < _args.Count; i++) {
1694                                 Expression arg = (Expression) _args [i];
1695                                 if (strArgs != "")
1696                                         strArgs += ", ";
1697                                 strArgs += arg.ToString ();
1698                         }
1699                         return _name.ToString () + '(' + strArgs + ')';
1700                 }
1701                 public override XPathResultType ReturnType { get { return XPathResultType.Any; }}
1702                 public override XPathResultType GetReturnType (BaseIterator iter)
1703                 {
1704                         return XPathResultType.Any;
1705                 }
1706
1707                 private XPathResultType [] GetArgTypes (BaseIterator iter)
1708                 {
1709                         // TODO: can we cache these? what if the types depend on the nsm?
1710                         XPathResultType [] rgArgs = new XPathResultType [_args.Count];
1711                         for (int iArg = 0; iArg < _args.Count; iArg++)
1712                                 rgArgs [iArg] = ((Expression) _args [iArg]).GetReturnType (iter);
1713                         return rgArgs;
1714                 }
1715                 public override object Evaluate (BaseIterator iter)
1716                 {
1717                         XPathResultType [] rgTypes = GetArgTypes (iter);
1718                         IXsltContextFunction func = null;
1719                         XsltContext context = iter.NamespaceManager as XsltContext;
1720                         if (context != null) {
1721                                 if (resolvedName)
1722                                         func = context.ResolveFunction (_name, rgTypes);
1723                                 else
1724                                         func = context.ResolveFunction (_name.Namespace, _name.Name, rgTypes);
1725                         }
1726
1727                         if (func == null)
1728                                 throw new XPathException ("function "+_name.ToString ()+" not found");
1729
1730                         object [] rgArgs = new object [_args.Count];
1731                         if (func.Maxargs != 0)
1732                         {
1733                                 XPathResultType [] rgFuncTypes = func.ArgTypes;
1734                                 for (int iArg = 0; iArg < _args.Count; iArg ++)
1735                                 {
1736                                         XPathResultType typeArg;
1737                                         if (rgFuncTypes == null)
1738                                                 typeArg = XPathResultType.Any;
1739                                         else if (iArg < rgFuncTypes.Length)
1740                                                 typeArg = rgFuncTypes [iArg];
1741                                         else
1742                                                 typeArg = rgFuncTypes [rgFuncTypes.Length - 1];
1743
1744                                         Expression arg = (Expression) _args [iArg];
1745                                         object result = arg.EvaluateAs (iter, typeArg);
1746                                         rgArgs [iArg] = result;
1747                                 }
1748                         }
1749                         return func.Invoke (context, rgArgs, iter.Current);
1750                 }
1751
1752                 internal override bool Peer {
1753                         get { return false; }
1754                 }
1755         }
1756 }