class/System.Core/System.Linq.Expressions/LambdaExpression.cs

   1 //
   2 // LambdaExpression.cs
   3 //
   4 // Author:
   5 //   Jb Evain (jbevain@novell.com)
   6 //   Miguel de Icaza (miguel@novell.com)
   7 //
   8 // (C) 2008 Novell, Inc. (http://www.novell.com)
   9 //
  10 // Permission is hereby granted, free of charge, to any person obtaining
  11 // a copy of this software and associated documentation files (the
  12 // "Software"), to deal in the Software without restriction, including
  13 // without limitation the rights to use, copy, modify, merge, publish,
  14 // distribute, sublicense, and/or sell copies of the Software, and to
  15 // permit persons to whom the Software is furnished to do so, subject to
  16 // the following conditions:
  17 //
  18 // The above copyright notice and this permission notice shall be
  19 // included in all copies or substantial portions of the Software.
  20 //
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28 //
  29
  30 using System;
  31 using System.Collections.ObjectModel;
  32 using System.Collections.Generic;
  33 using System.Reflection;
  34 using System.Reflection.Emit;
  35
  36 namespace System.Linq.Expressions {
  37
  38         public class LambdaExpression : Expression {
  39
  40                 Expression body;
  41                 ReadOnlyCollection<ParameterExpression> parameters;
  42
  43                 public Expression Body {
  44                         get { return body; }
  45                 }
  46
  47                 public ReadOnlyCollection<ParameterExpression> Parameters {
  48                         get { return parameters; }
  49                 }
  50
  51                 internal LambdaExpression (Type delegateType, Expression body, ReadOnlyCollection<ParameterExpression> parameters)
  52                         : base (ExpressionType.Lambda, delegateType)
  53                 {
  54                         this.body = body;
  55                         this.parameters = parameters;
  56                 }
  57
  58                 void EmitPopIfNeeded (EmitContext ec)
  59                 {
  60                         if (GetReturnType () == typeof (void) && body.Type != typeof (void))
  61                                 ec.ig.Emit (OpCodes.Pop);
  62                 }
  63
  64                 internal override void Emit (EmitContext ec)
  65                 {
  66                         ec.EmitCreateDelegate (this);
  67                 }
  68
  69                 internal void EmitBody (EmitContext ec)
  70                 {
  71                         body.Emit (ec);
  72                         EmitPopIfNeeded (ec);
  73                         ec.ig.Emit (OpCodes.Ret);
  74                 }
  75
  76                 internal Type GetReturnType ()
  77                 {
  78                         return this.Type.GetInvokeMethod ().ReturnType;
  79                 }
  80
  81                 public Delegate Compile ()
  82                 {
  83 #if TARGET_JVM || MONOTOUCH
  84                         System.Linq.jvm.Interpreter inter =
  85                                 new System.Linq.jvm.Interpreter (this);
  86                         inter.Validate ();
  87                         return inter.CreateDelegate ();
  88 #else
  89                         var context = new CompilationContext ();
  90                         context.AddCompilationUnit (this);
  91                         return context.CreateDelegate ();
  92 #endif
  93                 }
  94         }
  95 }