Share via

New for Visual Studio 2008 - Support for anonymous methods and lambda expressions

  • Article

One of my favorite new features for Code Analysis in Visual Studio 2008 is our support for analyzing anonymous methods and lambda expressions. While anonymous methods have been around in C# since Visual Studio 2005, lambda expressions are new for both C# and Visual Basic in Visual Studio 2008.

For those that are already familiar with the concept of anonymous methods (if not check out this article), lambda expressions provide a simpler, more concise syntax for writing inline methods. They also serve as the underpinnings of Linq.

Take the following code written in Visual Studio 2005 which converts a list of strings to uppercase, for example:

    internal static class StringFormatter
{
public static List<string> ToUpper(List<string> values, CultureInfo culture)
{
return values.ConvertAll(delegate(string value)
{
return value.ToUpper(culture);
});
}
}

Using the new lambda syntax, the equivalent can be written in C# and Visual Basic like so:

        internal static class StringFormatter
{
public static List<string> ToUpper(List<string> values, CultureInfo culture)
{
return values.ConvertAll(value => value.ToUpper(culture));
}
}

    Friend Module StringFormatter

Public Function ToUpper(ByVal values As List(Of String), ByVal culture As CultureInfo) As List(Of String)

Return values.ConvertAll(Function(value) value.ToUpper(culture))

End Function

End Module 

To understand how lambda expressions and anonymous methods are implemented underneath in IL (which is important for a tool like Code Analysis that runs over the binary and not the source), see the great in-depth posts by Raymond Chen for C# (Parts 1, 2, and 3) and Jared Parsons for Visual Basic (Parts 1, 2, 3, 4 and 5). Once you've read those posts, you'll understand why Code Analysis didn't get support for this for free.

What does this mean for Code Analysis users? Well, previously, in Visual Studio 2005, the engine would simply skip over these constructs and the user wouldn't find out about any violations, if any, contained within them. The good news is that we will now analyze them. The bad news is that any project making heavy use of anonymous methods is likely no longer Code Analysis clean on its upgrade to Visual Studio 2008. ;)

For a little more information on Code Analysis's support of anonymous methods, see the following topic: Anonymous Methods and Code Analysis (code formatting to be fixed for RTM).

Note: These is a bug in Beta 2 that prevents Code Analysis from analyzing lambdas/anonymous methods that access any locals or parameters outside of its own scope. This will be fixed in RTM of Visual Studio 2008.

Comments

  • Anonymous
    September 21, 2007
    PingBack from http://msdnrss.thecoderblogs.com/2007/09/21/new-for-visual-studio-2008-support-for-anonymous-methods-and-lambda-expressions/

  • Anonymous
    September 24, 2007
    Colin Beales - Blog : Exporting VSTS Load Test results to a new database Reference: How to move load...

  • Anonymous
    September 25, 2007
    Buck Hodges on Preview of the build notification tray applet power tool for TFS 2008. Brian Harry on...

  • Anonymous
    September 27, 2007
    It is time for another weekly roundup of news that focuses on .NET, agile and general development related

  • Anonymous
    October 10, 2007
    I'm pleased to announce that we've released a beta of the next version of FxCop . This release has a

  • Anonymous
    October 11, 2007
    The Visual Studio Code Analysis Team Blog announces the release of FxCop 1.36 Beta.This new version contains

  • Anonymous
    October 31, 2007
    I&#39;m currently trying to pro-actively drive the adoption of the .NET Framework 3.5 and VS 2008 within

  • Anonymous
    November 06, 2007
    i love c# but im not convenced on anonymous methods and lambda expressions

  • Anonymous
    November 25, 2007
    In previous posts about Code Metrics and Code Reviews , I explored some metrics and techniques that I

  • Anonymous
    August 17, 2008
    After what has to be the longest beta period of a product (after Gmail) - we&#39;ve finally released

  • Anonymous
    August 19, 2008
    We are pleased to announce that we've released the next version of FxCop . This release has a number

  • Anonymous
    September 07, 2008
    After a very long time, an FxCop update has been released . Here is a list of all that has changed: 200

  • Anonymous
    September 11, 2008
    【原文地址】 FxCop 1.36 Released 【原文发表日期】 20 August 08 08:49 David Kean宣布了 FxCop 1.36的发布 从David的博客中我们能看到以下几处优点