mcs/class/System.Core/System.Linq.Expressions/ExpressionVisitor.cs

   1 //
   2 // ExpressionVisitor.cs
   3 //
   4 // Author:
   5 //   Jb Evain (jbevain@novell.com)
   6 //
   7 // (C) 2008 Novell, Inc. (http://www.novell.com)
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 #if !NET_4_0
  30
  31 using System;
  32 using System.Collections.ObjectModel;
  33
  34 namespace System.Linq.Expressions {
  35
  36         abstract class ExpressionVisitor {
  37
  38                 protected virtual void Visit (Expression expression)
  39                 {
  40                         if (expression == null)
  41                                 return;
  42
  43                         switch (expression.NodeType) {
  44                         case ExpressionType.Negate:
  45                         case ExpressionType.NegateChecked:
  46                         case ExpressionType.Not:
  47                         case ExpressionType.Convert:
  48                         case ExpressionType.ConvertChecked:
  49                         case ExpressionType.ArrayLength:
  50                         case ExpressionType.Quote:
  51                         case ExpressionType.TypeAs:
  52                         case ExpressionType.UnaryPlus:
  53                                 VisitUnary ((UnaryExpression) expression);
  54                                 break;
  55                         case ExpressionType.Add:
  56                         case ExpressionType.AddChecked:
  57                         case ExpressionType.Subtract:
  58                         case ExpressionType.SubtractChecked:
  59                         case ExpressionType.Multiply:
  60                         case ExpressionType.MultiplyChecked:
  61                         case ExpressionType.Divide:
  62                         case ExpressionType.Modulo:
  63                         case ExpressionType.Power:
  64                         case ExpressionType.And:
  65                         case ExpressionType.AndAlso:
  66                         case ExpressionType.Or:
  67                         case ExpressionType.OrElse:
  68                         case ExpressionType.LessThan:
  69                         case ExpressionType.LessThanOrEqual:
  70                         case ExpressionType.GreaterThan:
  71                         case ExpressionType.GreaterThanOrEqual:
  72                         case ExpressionType.Equal:
  73                         case ExpressionType.NotEqual:
  74                         case ExpressionType.Coalesce:
  75                         case ExpressionType.ArrayIndex:
  76                         case ExpressionType.RightShift:
  77                         case ExpressionType.LeftShift:
  78                         case ExpressionType.ExclusiveOr:
  79                                 VisitBinary ((BinaryExpression) expression);
  80                                 break;
  81                         case ExpressionType.TypeIs:
  82                                 VisitTypeIs ((TypeBinaryExpression) expression);
  83                                 break;
  84                         case ExpressionType.Conditional:
  85                                 VisitConditional ((ConditionalExpression) expression);
  86                                 break;
  87                         case ExpressionType.Constant:
  88                                 VisitConstant ((ConstantExpression) expression);
  89                                 break;
  90                         case ExpressionType.Parameter:
  91                                 VisitParameter ((ParameterExpression) expression);
  92                                 break;
  93                         case ExpressionType.MemberAccess:
  94                                 VisitMemberAccess ((MemberExpression) expression);
  95                                 break;
  96                         case ExpressionType.Call:
  97                                 VisitMethodCall ((MethodCallExpression) expression);
  98                                 break;
  99                         case ExpressionType.Lambda:
 100                                 VisitLambda ((LambdaExpression) expression);
 101                                 break;
 102                         case ExpressionType.New:
 103                                 VisitNew ((NewExpression) expression);
 104                                 break;
 105                         case ExpressionType.NewArrayInit:
 106                         case ExpressionType.NewArrayBounds:
 107                                 VisitNewArray ((NewArrayExpression) expression);
 108                                 break;
 109                         case ExpressionType.Invoke:
 110                                 VisitInvocation ((InvocationExpression) expression);
 111                                 break;
 112                         case ExpressionType.MemberInit:
 113                                 VisitMemberInit ((MemberInitExpression) expression);
 114                                 break;
 115                         case ExpressionType.ListInit:
 116                                 VisitListInit ((ListInitExpression) expression);
 117                                 break;
 118                         default:
 119                                 throw new ArgumentException (string.Format ("Unhandled expression type: '{0}'", expression.NodeType));
 120                         }
 121                 }
 122
 123                 protected virtual void VisitBinding (MemberBinding binding)
 124                 {
 125                         switch (binding.BindingType) {
 126                         case MemberBindingType.Assignment:
 127                                 VisitMemberAssignment ((MemberAssignment) binding);
 128                                 break;
 129                         case MemberBindingType.MemberBinding:
 130                                 VisitMemberMemberBinding ((MemberMemberBinding) binding);
 131                                 break;
 132                         case MemberBindingType.ListBinding:
 133                                 VisitMemberListBinding ((MemberListBinding) binding);
 134                                 break;
 135                         default:
 136                                 throw new ArgumentException (string.Format ("Unhandled binding type '{0}'", binding.BindingType));
 137                         }
 138                 }
 139
 140                 protected virtual void VisitElementInitializer (ElementInit initializer)
 141                 {
 142                         VisitExpressionList (initializer.Arguments);
 143                 }
 144
 145                 protected virtual void VisitUnary (UnaryExpression unary)
 146                 {
 147                         Visit (unary.Operand);
 148                 }
 149
 150                 protected virtual void VisitBinary (BinaryExpression binary)
 151                 {
 152                         Visit (binary.Left);
 153                         Visit (binary.Right);
 154                         Visit (binary.Conversion);
 155                 }
 156
 157                 protected virtual void VisitTypeIs (TypeBinaryExpression type)
 158                 {
 159                         Visit (type.Expression);
 160                 }
 161
 162                 protected virtual void VisitConstant (ConstantExpression constant)
 163                 {
 164                 }
 165
 166                 protected virtual void VisitConditional (ConditionalExpression conditional)
 167                 {
 168                         Visit (conditional.Test);
 169                         Visit (conditional.IfTrue);
 170                         Visit (conditional.IfFalse);
 171                 }
 172
 173                 protected virtual void VisitParameter (ParameterExpression parameter)
 174                 {
 175                 }
 176
 177                 protected virtual void VisitMemberAccess (MemberExpression member)
 178                 {
 179                         Visit (member.Expression);
 180                 }
 181
 182                 protected virtual void VisitMethodCall (MethodCallExpression methodCall)
 183                 {
 184                         Visit (methodCall.Object);
 185                         VisitExpressionList (methodCall.Arguments);
 186                 }
 187
 188                 protected virtual void VisitList<T> (ReadOnlyCollection<T> list, Action<T> visitor)
 189                 {
 190                         foreach (T element in list) {
 191                                 visitor (element);
 192                         }
 193                 }
 194
 195                 protected virtual void VisitExpressionList (ReadOnlyCollection<Expression> list)
 196                 {
 197                         VisitList (list, Visit);
 198                 }
 199
 200                 protected virtual void VisitMemberAssignment (MemberAssignment assignment)
 201                 {
 202                         Visit (assignment.Expression);
 203                 }
 204
 205                 protected virtual void VisitMemberMemberBinding (MemberMemberBinding binding)
 206                 {
 207                         VisitBindingList (binding.Bindings);
 208                 }
 209
 210                 protected virtual void VisitMemberListBinding (MemberListBinding binding)
 211                 {
 212                         VisitElementInitializerList (binding.Initializers);
 213                 }
 214
 215                 protected virtual void VisitBindingList (ReadOnlyCollection<MemberBinding> list)
 216                 {
 217                         VisitList (list, VisitBinding);
 218                 }
 219
 220                 protected virtual void VisitElementInitializerList (ReadOnlyCollection<ElementInit> list)
 221                 {
 222                         VisitList (list, VisitElementInitializer);
 223                 }
 224
 225                 protected virtual void VisitLambda (LambdaExpression lambda)
 226                 {
 227                         Visit (lambda.Body);
 228                 }
 229
 230                 protected virtual void VisitNew (NewExpression nex)
 231                 {
 232                         VisitExpressionList (nex.Arguments);
 233                 }
 234
 235                 protected virtual void VisitMemberInit (MemberInitExpression init)
 236                 {
 237                         VisitNew (init.NewExpression);
 238                         VisitBindingList (init.Bindings);
 239                 }
 240
 241                 protected virtual void VisitListInit (ListInitExpression init)
 242                 {
 243                         VisitNew (init.NewExpression);
 244                         VisitElementInitializerList (init.Initializers);
 245                 }
 246
 247                 protected virtual void VisitNewArray (NewArrayExpression newArray)
 248                 {
 249                         VisitExpressionList (newArray.Expressions);
 250                 }
 251
 252                 protected virtual void VisitInvocation (InvocationExpression invocation)
 253                 {
 254                         VisitExpressionList (invocation.Arguments);
 255                         Visit (invocation.Expression);
 256                 }
 257         }
 258 }
 259
 260 #endif