Neal Gafter explains why Microsoft has introduced dynamic typing in C# 4.0, what it is useful for - Interoperate with dynamic languages, Using reflection-like API, Interacting with COM -, what is DLR, and why they have chosen the dynamic type instead of other possible solutions.
Optional parameters have always been part of .NET, but with C# unwilling to support it, using them was generally considered taboo unless work with COM libraries. Now that C# 4 does support them, we are starting to see them used for a lot more than just legacy code. Other uses include interoperability with dynamic languages, immutable data structures, and various parts of ASP.NET MVC.
CSI is a simple C# interpreter allowing command-line compilation of standalone C# files. A new version has been released to support .NET 4.0. CSI is open source with a full test suite.
Having caught with the recent advances in Microsoft’s C# 4, the Mono team is now playing with their own extensions to the language. The two features they are experimenting with are string interpolation and support for multiple return values.
Creating wrapper functions for pre-existing stored procedures is surprisingly difficult in .NET. Stored procedures have certain calling conventions that aren’t generally used in the .NET Framework and many of them are not supported at all. For example, C# doesn’t support optional parameters and neither .NET language supports optional parameters on nullable types.
C# does not work well with boxed numerical values. Unlike Visual Basic, the basic numeric comparison operators such as == do not work with boxed types even when both values are the same type. Fortunately with C# 4 you can avoid these problems by using the dynamic keyword.
Using the new DLR features in VB 10 and C# 4 you can build a configuration-free ORM that works well with legacy stored procedures. Though accessed using normal object-dot-property syntax, all the data objects are built at runtime based solely on the information returned by the database. And this is done with no interfaces to define, classes to implement, or data mapping definitions to write.
In this interview Eric Nelson talks about what’s coming in VS 2010, the C# – VB.NET convergence, the introduction of Parallel as a library, and Azure cloud computing.
In this interview made by InfoQ’s Sadek Drobi, Don Syme, a Senior Researcher at Microsoft Research, answers questions mostly on F#, but also on functional programming, C# generics, type classes in Haskell, similarities between F# and Scala.
