private bool TryResolveOdataExpression(MethodCallNode node, out Expression expression)
{
expression = null;
switch (node.Name)
{
case "isof":
case "cast":
if (node.Children.Count > 2 || node.Children.Count < 1)
{
throw CreateParseException(node, "Only one or two arguments to cast operator is allowed.");
}
TypeNameNode castTypeArg;
Expression operand;
if (node.Children.Count == 1)
{
castTypeArg = node.Children[0] as TypeNameNode;
operand = this.thisParam;
}
else
{
operand = ParseExpression(node.Children[0]);
castTypeArg = node.Children[1] as TypeNameNode;
}
if (castTypeArg == null)
{
throw CreateParseException(node, "Argument to cast is required to be a type literal.");
}
var type = ResolveType(castTypeArg);
if (node.Name == "cast")
{
expression = Expression.Convert(operand, type);
}
else if (node.Name == "isof")
{
expression = Expression.TypeIs(operand, type);
}
return(true);
case "iif":
ParseConditionalOperator(node, ref expression);
return(true);
}
var memberCandidates = QueryFunctionMapping.GetMemberCandidates(node.Name, node.Children.Count);
foreach (var memberMapping in memberCandidates)
{
if (TryResolveMemberMapping(memberMapping, node, out expression))
{
return(true);
}
}
return(false);
}
private bool TryMapKnownOdataFunction(Expression origNode,
MemberInfo member,
IEnumerable <Expression> arguments,
out Expression odataExpression)
{
ReplaceQueryableMethodWithCorrespondingEnumerableMethod(ref member, ref arguments);
QueryFunctionMapping.MemberMapping memberMapping;
if (!QueryFunctionMapping.TryGetMemberMapping(member, out memberMapping))
{
odataExpression = null;
return(false);
}
var odataArguments = arguments.Select(Visit).Cast <object>().ToArray();
var callFormat = memberMapping.PreferredCallStyle == QueryFunctionMapping.MethodCallStyle.Chained
? memberMapping.ChainedCallFormat
: memberMapping.StaticCallFormat;
odataExpression = Format(origNode, memberMapping.LocalExecutionPreferred, callFormat, odataArguments);
return(true);
}