private static AstNode ModifyLambdaForSelectMany(LambdaExpression lambdaExpression,
ParenthesizedExpression parenthesizedlambdaExpression,
InvocationExpression invocationExpression)
{
AstNode node = lambdaExpression;
if (invocationExpression.Arguments.Count > 0 && invocationExpression.Arguments.ElementAt(0) == lambdaExpression) // first one, select the collection
{
// need to enter a cast for (IEnumerable<dynamic>) on the end of the lambda body
var selectManyExpression = new LambdaExpression
{
Body =
new CastExpression(new SimpleType("IEnumerable<dynamic>"),
new ParenthesizedExpression((Expression)lambdaExpression.Body.Clone())),
};
selectManyExpression.Parameters.AddRange(lambdaExpression.Parameters.Select(x => (ParameterDeclaration)x.Clone()));
node = new CastExpression(new SimpleType("Func<dynamic, IEnumerable<dynamic>>"),
new ParenthesizedExpression(selectManyExpression.Clone()));
}
else if (invocationExpression.Arguments.Count > 1 && invocationExpression.Arguments.ElementAt(1) == lambdaExpression) // first one, select the collection
{
node = new CastExpression(new SimpleType("Func<dynamic, dynamic, dynamic>"), parenthesizedlambdaExpression.Clone());
}
return(node);
}
public override AstNode VisitLambdaExpression(LambdaExpression lambdaExpression)
{
var clonLambdaExpression = (LambdaExpression)base.VisitLambdaExpression(lambdaExpression);
if (clonLambdaExpression != null)
{
lambdaExpression = clonLambdaExpression;
}
if (lambdaExpression.Body.IsNull)
{
var l = (LambdaExpression)lambdaExpression.Clone();
l.Body = new IdentifierExpression(lambdaExpression.Parameters.Last().Name);
return(l);
}
return(lambdaExpression.Clone());
}
public void TestCloneLambdaExpression()
{
LambdaExpression lambdaExpression = new LambdaExpression()
{
Expression = new BooleanLiteral()
{
Value = true
},
Parameters = new List <string>()
{
"p1"
}
};
var clone = lambdaExpression.Clone() as LambdaExpression;
Assert.IsFalse(ReferenceEquals(lambdaExpression, clone));
Assert.IsFalse(ReferenceEquals(lambdaExpression.Expression, clone.Expression));
Assert.IsFalse(ReferenceEquals(lambdaExpression.Parameters, clone.Parameters));
Assert.AreEqual(lambdaExpression, clone);
}
public override object VisitLambdaExpression(LambdaExpression lambdaExpression, object data)
{
var invocationExpression = lambdaExpression.Parent as InvocationExpression;
if (invocationExpression == null)
{
return(base.VisitLambdaExpression(lambdaExpression, data));
}
var target = invocationExpression.Target as MemberReferenceExpression;
if (target == null)
{
return(base.VisitLambdaExpression(lambdaExpression, data));
}
AstNode node = lambdaExpression;
var parenthesizedlambdaExpression = new ParenthesizedExpression(lambdaExpression.Clone());
switch (target.MemberName)
{
case "Sum":
case "Average":
node = ModifyLambdaForNumerics(lambdaExpression, parenthesizedlambdaExpression);
break;
case "Max":
case "Min":
node = ModifyLambdaForMinMax(lambdaExpression, parenthesizedlambdaExpression);
break;
case "OrderBy":
case "OrderByDescending":
case "GroupBy":
case "Recurse":
case "Select":
node = ModifyLambdaForSelect(parenthesizedlambdaExpression, target);
break;
case "SelectMany":
node = ModifyLambdaForSelectMany(lambdaExpression, parenthesizedlambdaExpression, invocationExpression);
break;
case "Any":
case "all":
case "First":
case "FirstOrDefault":
case "Last":
case "LastOfDefault":
case "Single":
case "Where":
case "Count":
case "SingleOrDefault":
node = new CastExpression(new SimpleType("Func<dynamic, bool>"), parenthesizedlambdaExpression.Clone());
break;
}
lambdaExpression.ReplaceWith(node);
if (node != lambdaExpression)
{
return(node.AcceptVisitor(this, null));
}
return(base.VisitLambdaExpression(lambdaExpression, null));
}