Krzysztof Cwalina

Somebody asked me today, if we have a collection that is disposable and calls dispose on all its items when the collections.Dispose method is called. You can implement such collection by inheriting from List<T> and adding Dispose logic. If you add...

I always thought about writing down the laws of APIs design. By "laws", I mean principles that don’t seem to change based on the particular scenario at hand, whether the API is low of high level, etc. Here is my first try. I would appreciate any comments....

Today, I was reviewing a set of recommendation for naming types intended to be inherited from. The author suggested using the “Base” suffix for such types. I personally don’t like to do this. Here are the reasons: First, what do you call base of a...

Channel 9 just posted a video in which our API usability engineers talk about one of the studies they conducted recently, but what’s even more interesting, in part two of the story, they show a clip from an actual study where a participant writes a workflow...

I just saw an interesting post that talks about a general pattern of immutable reference types. Good read. I highly recommend it! At the end of the post the author suggests that we add “value object” generic collection to the BCL. It’s an interesting...

There is an interesting thread on MSDN newsgroups (see "event arguments" thread) about the design of our eventing APIs. The question is why do we even have EventArgs class (which is empty)? Should we just allow the second parameter to the event handlers...

Daniel Moth asked, in his post , how to choose between a generic type parameter vs. a formal parameter of typed as System.Type. For example, the following two members seem equivalent. public class Activator { public static object CreateInstance(Type...

The Framework Design Guidelines book comes with a tool called TxRef. The tool was built with Beta 2 version of the Framework 2.0 and will not compile on the RTM version. Kathy just posted a fix to the problem. See http://blogs.msdn.com/kathykam/archive...

The Framework Design Guidelines book is being read by readers we never thought would be interested in API design. Richard has captured a photo showing one of the readers being simply glued to the Type Design chapter.

I did an interview for SYS-CON TV. I talked about the Framework Design Guidelines book and other API related things. The interview can be viewed at http://www.sys-con.tv/read/137736.htm .

Online publishers have started shipping the Framework Design Guidelines book. Before, it was pre-order-only. I think Brad and I deserve a ship party :-) BTW, “ship party” is the term we use at Microsoft for a party we organize for ourselves after releasing...

Addison Wesley, the publisher of the Framework Design Guidelines book has posted a freely downloadable chapter . The chapter talks about type design.

We don’t recommend using List<T> in public APIs for two reasons. List<T> is not designed to be extended. i.e. you cannot override any members. This for example means that an object returning List<T> from a property won’t be able...

Many people ask how the new.NET Framework 2.0 generic collections relate to the non-generic collections we shipped before. So, here you go. The most important types are in bold font. List<T> is basically a better ArrayList. It is optimized for...

I just found a very interesting blog written by Dave Green (an architect of the Windows Workflow Foundation). One of the posts explains the main motivations for creating a workflow framework. In general I am a big fan of the work this team has done...

I just wanted to blog about some interesting API design discussion we had recently . We discussed whether to relax the event design guidelines to allow value type "event args." This would make raising some events cheaper. public struct SomethingHappenedEventArgs...

I found a very encouraging post about the new tracing APIs that we added to .NET Framework 2.0. Kathleen Dollard wrote : “ Sometimes Microsoft absolutely amazes me. I know .NET is big, and I know that the 2.0 release is rather overwhelming even to Softies...

I just wanted to post something to summarize the PDC 2005. PDC started for me on Monday. Brad and I were presenting at a precon on Designing Reusable APIs. 6 hours total. The slides can be downloaded here . We were tweaking slides till midnight...

Since I have been preparing for the PDC and finishing the book , I neglected blogging. All ideas for posts were just ending up in the “to do” folder (yes, Outlook drives my life J). Now, I will try to catch up. I was reading Paul Grahm’s essay on Design...

I have just heard from the publisher that the Framework Design Guidelines book just went to print. To celebrate and to thank for the contributions, I thought I would blog the list of people who provided annotations for the book: Brad Abrams , Mark...

Rico just posted a new performance quiz where he compares performance of List<T> and ArrayList in some simple scenarios. List<T> is my Whidbey baby, so of course I had to answer that List<T> is faster :-)

Steven Clarke has an excellent post about using factories in APIs . The post explains why some developers find factories difficult to use.

After posting about the Scenario Driven Design and the Design Guidelines book we are working on, I got several questions on that is "progressive API". Coincidentally I just submitted the final manuscript for a chapter that has a section on progressive APIs, so here is the related excerpt:...

The beta release of the PowerCollections library has been posted today. See http://wintellect.com/WEBLOGS/pgolde/archive/2005/06/03/1304.aspx .

Recently somebody asked me to clarify one of the exception guidelines . They were asking whether it's ok to have a property on exception types that provides access to an error code. I added the following annotation to one of the guidelines: Do not...