How to detect if a LINQ enumeration is materialized?

Posted by Peter Lillevold on Stack Overflow See other posts from Stack Overflow or by Peter Lillevold
Published on 2010-05-18T13:30:30Z Indexed on 2010/05/18 13:41 UTC
Read the original article Hit count: 271

Filed under:

LINQ

|

linq-to-objects

Is there some way of detecting whether an enumerable built using LINQ (to Objects in this case) have been materialized or not? Other than trying to inspect the type of the underlying collection?

Specifically, since enumerable.ToArray() will build a new array even if the underlying collection already is an array I'm looking for a way of avoiding ToArray() being called twice on the same collection.

© Stack Overflow or respective owner

Related posts about LINQ

LINQ to SQL, LINQ to XML and Accessing DataTable using LINQ

as seen on C# Corner - Search for 'C# Corner'
This article demonstrates how to use LINQ on DataTable, XML Data using LINQ to XML and SQL server data base using LINQ to SQL Classes. >>> More
Exception with Linq2SQL Query

as seen on Stack Overflow - Search for 'Stack Overflow'
I am running a query using Linq2SQL that comes down to following query: DateTime? expiration = GetExpirationDate(); IQueryable<Persons> persons = GetPersons(); IQueryable<Items> subquery = from i in db.Items where i.ExpirationDate >= expiration … >>> More
What is Linq?

as seen on ASP.net Weblogs - Search for 'ASP.net Weblogs'
The way data can be retrieved in .NET. LINQ provides a uniform way to retrieve data from any object that implements the IEnumerable<T> interface. With LINQ, arrays, collections, relational data, and XML are all potential data sources. Why LINQ?With LINQ, you can use the same syntax to retrieve… >>> More
Mixing Silverlight-Specific System.Xml.Linq dll with Non-Silverlight System.Xml.Linq dll

as seen on Stack Overflow - Search for 'Stack Overflow'
I have a Logic layer that references Silverlight's System.Xml.Linq dll and a GUI that is in WPF (hence using the non-Silverlight System.Xml.Linq dll). When I attempt to pass an XElement from GUI project to a method in the Logic project, I am getting (basically) "XElement is not of type XElement" errors… >>> More
Subsonic 3 LINQ vs LINQ to SQL

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I am using SQL Server 2005 in a project. I have to decide about datalayer. I would like to use LINQ in my project. I saw SubSonic 3 supporting LINQ and I also have option for LINQ to SQL, because i can have typed lists from LINQ to SQL. I am wondering what is different between LINQ to SQL and… >>> More

Related posts about linq-to-objects

Linq To Objects Auto Increment Number

as seen on Stack Overflow - Search for 'Stack Overflow'
This feels like a completely basic question, but, for the life of me, I can't seem to work out an elegant solution. Basically, I am doing a Linq Query creating a new object from the query. In the new object, I want to generate a auto-incremented number to allow me to keep a selection order for… >>> More
When is LINQ (to objects) Overused?

as seen on Stack Overflow - Search for 'Stack Overflow'
My career started as a hard-core functional-paradigm developer (LISP), and now I'm a hard-care .net/C# developer. Of course I'm enamored with LINQ. However, I also believe in (1) using the right tool for the job and (2) preserving the KISS principle: of the 60+ engineers I work with, perhaps only… >>> More
LinQ to objects GroupBy() by object and Sum() by amount

as seen on Stack Overflow - Search for 'Stack Overflow'
Hello, I have pretty simple case which I started solving using foreach(), but then I thought I could do It using Linq Basically I have IList that contains PaymentTransaction objects and there are 2 properties Dealer and Amount I want to GroupBy() by Dealer and Sum() bv amount. I tried to accomplish… >>> More
Linq-To-Objects group by

as seen on Stack Overflow - Search for 'Stack Overflow'
Hey, I'm building a software for timereporting I have a Dictionary<string, Dictionary<string, double>>. The key in the main dictionary is a users name and their value is a dictionary of . I have a function GetDepartment(string UserName) which returns a string with the users department… >>> More
Switching from LinqToXYZ to LinqToObjects

as seen on Stack Overflow - Search for 'Stack Overflow'
In answering this question, it got me thinking... I often use this pattern: collectionofsomestuff //here it's LinqToEntities .Select(something=>new{something.Name,something.SomeGuid}) .ToArray() //From here on it's LinqToObjects .Select(s=>new SelectListItem() { … >>> More