private static AstNode ModifyLambdaForMinMax(LambdaExpression lambdaExpression,
ParenthesizedExpression parenthesizedlambdaExpression)
{
var node = new CastExpression(new SimpleType("Func<dynamic, IComparable>"), parenthesizedlambdaExpression.Clone());
var castExpression = GetAsCastExpression(lambdaExpression.Body);
if (castExpression != null)
{
var castToType = new SimpleType("Func", new SimpleType("dynamic"), castExpression.Type.Clone());
node = new CastExpression(castToType, parenthesizedlambdaExpression.Clone());
}
return(node);
}
private static AstNode ModifyLambdaForSelect(ParenthesizedExpression parenthesizedlambdaExpression,
MemberReferenceExpression target)
{
var parentInvocation = target.Target as InvocationExpression;
if (parentInvocation != null)
{
var parentTarget = parentInvocation.Target as MemberReferenceExpression;
if (parentTarget != null && parentTarget.MemberName == "GroupBy")
{
return(new CastExpression(new SimpleType("Func<IGrouping<dynamic,dynamic>, dynamic>"), parenthesizedlambdaExpression.Clone()));
}
}
return(new CastExpression(new SimpleType("Func<dynamic, dynamic>"), parenthesizedlambdaExpression.Clone()));
}
private static AstNode ModifyLambdaForNumerics(LambdaExpression lambdaExpression,
ParenthesizedExpression parenthesizedlambdaExpression)
{
var castExpression = GetAsCastExpression(lambdaExpression.Body);
if (castExpression != null)
{
var castToType = new SimpleType("Func", new SimpleType("dynamic"), castExpression.Type.Clone());
return(new CastExpression(castToType, parenthesizedlambdaExpression.Clone()));
}
var expression = new LambdaExpression
{
Body = new CastExpression(new PrimitiveType("decimal"), new ParenthesizedExpression((Expression)lambdaExpression.Body.Clone())),
};
expression.Parameters.AddRange(lambdaExpression.Parameters.Select(x => (ParameterDeclaration)x.Clone()));
return(new CastExpression(new SimpleType("Func<dynamic, decimal>"),
new ParenthesizedExpression(expression)));
}
private static AstNode ModifyLambdaForSelect(ParenthesizedExpression parenthesizedlambdaExpression,
MemberReferenceExpression target)
{
var parentInvocation = target.Target as InvocationExpression;
if (parentInvocation != null)
{
var parentTarget = parentInvocation.Target as MemberReferenceExpression;
if (parentTarget != null)
{
if (parentTarget.MemberName == "GroupBy")
{
return(new CastExpression(new SimpleType("Func<IGrouping<dynamic,dynamic>, dynamic>"), parenthesizedlambdaExpression.Clone()));
}
if (parentTarget.MemberName == "Range")
{
var identifierExpression = parentTarget.Target as IdentifierExpression;
if (identifierExpression != null && identifierExpression.Identifier == "Enumerable")
{
// support for Enumerable.Range(x, y).Select()
// convert Enumerable.Range(x, y) to Enumerable.Range(x, y).Cast<dynamic>()
var enumerableRange = parentInvocation.Clone();
var castToDynamic = new MemberReferenceExpression(enumerableRange, "Cast", new AstType[] { new SimpleType("dynamic") });
var dynamicEnumerableRange = new InvocationExpression(castToDynamic);
parentInvocation.ReplaceWith(dynamicEnumerableRange);
}
}
}
}
return(new CastExpression(new SimpleType("Func<dynamic, dynamic>"), parenthesizedlambdaExpression.Clone()));
}
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 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));
}
