Question

I am thinking about code standards for a .net project (c sharp language) and I personally really like using lambda expressions in the various extension methods on IEnumerable etc (Where, GroupBy, blah, blah) and don’t really like the LINQ syntax.

I know it is a personal preference thing, so I am not asking which is best, but for me and my team we tend to find the lambda approach to be more easily readable. So I am thinking of saying in our coding standards to always use the Lambda approach but I got to thinking…

Is there anything that can only be achieved using LINQ syntax? By something I mean that you could build a particular expression tree using LINQ that you simply could not using the extension methods with lambda expressions. I am thinking that the answer is no as tools like resharper and linqpad are able to convert between them and I have been able to work out everything I have ever needed in lambda but I wonder if there is an edge case somewhere that the smart people on here know about?

Answer 1

“Possible” and “convenient” are different ;p Everything is possible; LINQ syntax ultimately compiles to lambda syntax, and there are things possible with extension syntax that aren’t possible in LINQ syntax (Distinct() in C#, for example, although it exists in VB.NET LINQ).

However! When you have lots of variables in a LINQ query, that is a pain to map, as you would need lots of additional projections to intermediate objects (probably anonymous types); for example, try writing (in lambda syntax):

var query = from x in xSource
            from y in x.SomeCollection
            from z in zSource
            let foo = x.Foo + z.SomeMethod()
            order by foo
            select new {x,y,z,foo};

it is possible, but frankly a PITA.