lambda

Why can't you edit and continue debugging when there's a Lambda expression in the method?

I've seen it said in other questions that the Linq query syntax compiles to a Lambda. So why can you not do edit-and-continue when there is a Lambda expression in the method, while with query notation you can? What's most infuriating, and is seriously making me consider switching to using query notation everywhere, is that even if your...

Shortest method to find Min and Max length of word in array.

I have following array string[] words = { "cherry", "apple", "blueberry", "banana", "mango", "orange", "pineapple" }; I want to find the Max and Min no. of alphabets. e.g. Max = 9 (for pineapple) and Min = 5 (for apple) Which is the shortest method to do this. ...

Which one is better lambda expressions or .....

I have following LINQ to SQL query from msg in TblUserMessages join user in Aspnet_Users on msg.FromUserID equals user.UserId select new { msg.FromUserID, msg.ToUserID, msg.MessageLocationID, msg.MessageID, user.UserName } And following lambda expression: TblUserMessages .Join ( Aspne...

Closures and Lambda in C#

I get the basic principles of closures and lambda expressions but I'm trying to wrap my mind around what is happening behind the scenes and when it is/isn't practical to use them in my code. Consider the following example, that takes a collection of names and returns any names that begin with the letter C... static void Main(string...

How to do smart conversion of Lambda expressions between DTO and target-class?

I have a problem to resolve here: At the highest layers, we work with a dto. We use Entity framework in the Data layer, working with the entities, converting the results as dtos. We have some custom searches being done in the upper layers, the question is: how to translate these lambda expressions between classes, assuming that each pr...

Lambda query to reverse order a list by date

I have this function that shows a list of messages in reverse order. protected void setupMessages(IList<Message> Messages) { List<Message> messages = new List<Message>() ; messages.AddRange( Messages.OrderBy(message => message.DateAdded).Reverse()); MessagesRepeater.DataSource = messages; MessagesRepeater.DataBind(...

Lambda Func<> and Fluent

There are lots of Fluent implementations out there now that work with Lambdas to do things that are quite neat. I'd like to wrap my brain around it so I can start creating some of these things, but I have yet to find an explanation that my brain understands. Consider this simple example of a Person Validator public class PersonValidat...

Lambda to Expression tree conversion

I will keep it really simple, How do I get expression tree out of lambda?? or from query expression ? ...

Retrieving static field in generic method by lambda expression

Let's say i got this: public class Foo{ public string Bar; } Then i want to create a 'static reflection' to retrieve value of Bar like this: public void Buzz<T>(T instance, Func<T, string> getProperty){ var property = getProperty(instance); } That should work. But what if Foo looks like this? public class Foo{ ...

C# Lambda Expression not returning expected result

I am using a lamda expression to filter a query. Basically, I have lines that are composed of segments and these segments are marked as deleted, inserted or null. What I want returned are segments that have been marked as deleted but whose any sibling IS NOT marked as deleted. As an example, Line: "Soylent Green is people!" Broken ...

C# Lambda+Extensions+Fluent - How Would I Do This?

I want to be able to create "Transformation" classes that take a given object, perform a series of transformations on it (i.e. change property values) and keeps track of the transformations performed. The transformation performed will vary based on the properties of the object provided. I want to be able to apply transformation rules (...

Does Actionscript3 offer list comprehensions or lambda calculus?

I'm porting some code I prototyped in python over to flash and while actionscript doesn't suck quite as bad as I expected (I hear v3 is quite a lot better than v2!) there's still some stuff I'm having to do that seems overly prosaic / boilerplate e.g. summing a list... var a:int = 0; for each ( var value:int in annual_saving ) { ...

split generic list

I need to split a list into two equal lists. For Example: I have a list which consists of 10 items. I need to split the list into two equal parts(each with 5 items) I have a list which consists of 9 items sometimes. I need to split the list into two parts(one with 5 items and other with 4 items) Please suggest a solution for this. ...

How can i get items which are equal to string[] ?

Hi, I have an array of strings var controlsToGet = new[] {"lblHome","lblContact"}; I have List<LanguageControl> and LanguageControl class holds Controls in it. I want to get Controls from List which Control.Name == controlsToGet I am looking for something like that var all = fooelements.where(l=>l.Control.Name == controlsToGet); ...

What in the world does this code do? (C#)

Hi, I've been reading a book which is in C#. I'm a VB.NET developer (and a very junior one at that) and I'm having a lot of trouble with the following code that contains lots of things I've never seen before. I do have a basic knowledge of Lambda Expressions. public List<T> SortByPropertyName(string propertyName, bool ascending) { ...

Collection-valued parameters with The Entity Framework ?

Hi, In my last project i decided to use Entity Framework and it was all going well until i try to get datas with "where in", i got an error. After a tiny search i ve come up with this post and that post. This is what i am trying to do var all = fooelements .Where(l=>controlsToGet .Contains(l....

Specifying constraints for fmin_cobyla in scipy

I use Python 2.5. I am passing bounds to the cobyla optimisation: import numpy from numpy import asarray Initial = numpy.asarray [2, 4, 5, 3] # Initial values to start with #bounding limits (lower,upper) - for visualizing #bounds = [(1, 5000), (1, 6000), (2, 100000), (1, 50000)] # actual passed bounds b1 = lambda x: 5000 ...

Is it possible to use Select(l=> new{}) with SelectMany in EntityFramework

Hi, I am trying something that i not really sure but i want to ask here if it s possible. Is it able to be done ? public IQueryable<Info> GetInfo(int count, byte languageId) { return db.Info.SelectMany(i => i.LanguageInfo) .Where(l => l.Language.id == languageId) ...

Building Linq Expressions with Variables

I am using Linq and the Entity Framework. I have a Page Entity, that has a many-to-many relationship to a Tag Entity. I want to create a Linq query that pulls all pages that match all of the supplied Tags (in the form of a Int64[]). I have tried various WhereIn, and BuildContainsExpression examples, but none are working as expected. ...

C#: How to remove a lambda event handler

Possible Duplicates: Unsubscribe anonymous method in C# How do I Unregister anonymous event handler I recently discovered that I can use lambdas to create simple event handlers. I could for example subscribe to a click event like this: button.Click += (s, e) => MessageBox.Show("Woho"); But how would you unsubscribe it? ...