Immo Landwerth

• How to browse the .NET Reference Source

  2 days ago

  And here you go :)

• Using Portable Class Libraries with Xamarin

  Feb 27, 2014 at 8:53 PM

  @Stilgar: We hear you. I can't commit to anything but it's certainly on our list.

• How to browse the .NET Reference Source

  Feb 24, 2014 at 7:15 PM

  Clearly our main takeaway for this one is that we shouldn't publish videos without audio :)

  Sorry guys. The next one will either have a human talking to it or at least some background music.

• TWC9: Helios, Bing Code Search Extension, Azure Symbol Set and more...

  Feb 23, 2014 at 10:29 AM

  Regarding Ninja: According to Wikipedia, you're both correct:

  In English, the plural of ninja can be either unchanged as ninja, reflecting the Japanese language's lack of grammatical number, or the regular English plural ninjas

  :D

• TWC9: What not to do with ASP.NET, explore .NET 4.5.1, more Async tips, Conan and more

  Feb 16, 2014 at 9:24 AM

  Glad you like it! Please note that right now that the SQLite package can't be consumed from a PCL directly. Stay tuned.

• Auto History Extension

  Jan 24, 2014 at 9:50 AM

  It's possible that I missed this, but how often are snapshots taken? Is that every manual + autosave operation?

  Also, I've to admit that I find the tool window a bit too bulky.

• Immo Landwerth and Andrew Arnott: Inside Immutable Collections

  Mar 20, 2013 at 11:51 AM

  10 hours ago, felix9 wrote

  If the MSR work you talked about is this
  http://research.microsoft.com/apps/pubs/default.aspx?id=170528

  Yes, I believe that's the paper we referred to during the interview.

  I like language innovation a lot but things that affect the type subsystem in such a fundamental way are very hard to incorporate into an existing language like C#. It seems impossible to this on "on the side" as immutability is quite sticky; meaning you those sort of constraints need to be propagated around in the entire system to be beneficial.

  Also, applying this to the hundreds of thousands of APIs in the .NET FX might be prohibitively expensive...

• Immo Landwerth and Andrew Arnott: Inside Immutable Collections

  Mar 19, 2013 at 7:22 PM

  Hi Marcus,

  That's a lot of interesting questions! Let me take them one by one.

  3 hours ago

  Why not allow user to select implementation using a factory function? The allocator most often knows how the collection will be used. For example that indexer or add must be O(1). The current AVL solution doesn't sound too good for paging and slicing. How would I create a slice of an ImmutableList? Did you look at Dlang ranges?

  I haven't looked at Dlang ranges -- Andrew might have more context there. In general, we are not convinced that offering a knob for every option is the right thing. In the end, our goal is delivering a list of collection types that work for a wide variety while still being easy to use and agree upon. The Roslyn use case we brought up is quite special -- Roslyn has super tight perf constraints that most developers will not have. Once you are in this boat, chances are you want to have more control than what we can realistically offer in the BCL.

  For those case we still offer the immutable interfaces as the exchange currency.

  And .ToList() is commonly used on IEnumerables to materialize them from linq or other enums to make sure they are O(1) indexed. Not only to get a safe copy to foreach over. Will you add a ToImmutableList()? And will that be a noop if the IEnumerable is already an ImmList?

  Our library offers an extension method for IEnumerable<T> that provides ToImmutableList().

  If you call ToImmutableList() on an immutable list, you will get back the same instance, assuming it uses the default comparer. If it doesn't we change the comparer. In any case, that's an O(1) operation.

  Is that what you are looking for?

  An immutable list where add/indexer is O(1) with an array backing store would be nice. The allocation time would be amortized. The extra space created in array realloc could be used for non concurrent adds or adds in creator thread.

  We still entertain the idea of ImmutableArray<T>. The type would be a struct wrapper around an array. Constructing would copy the array once to avoid anybody can violate the immutability guarantee. Indexer would be O(1). However, we wouldn't support persistent operations. In other words, adding or changing items would not be supported.

• Channel 9 turns 9!

  Mar 15, 2013 at 8:00 AM

  Happy Birthday! You guys are the reason I decided to join the dark side

  Hope there are at least nine more years to come.

• Erik Meijer, Immo Landwerth, and Andrew Arnott: Immutable Collections for .NET

  Jan 20, 2013 at 2:18 PM

  13 hours ago

  Nice addition! But I wonder for how long they will be relevant? In Win8 apps! where HTML5, Javascript and C++ are first class citizens and .NET has been demoted to second class citizen?

  First of all I don't think that's true. I was the PM driving the .NET surface area you can use when targeting Windows 8 store apps. Let me tell you: the entire .NET Framework team and large chunks of Visual Studio spend significant amount of resources to make this an awesome experience. As with every technology that is advanced enough by adding a non-trivial set of features, there are rough edges and I'm the first to admit that. However, the same is true for C++ and JavaScript given that Windows Store apps run in a different environment that are new for them, too. We all try very hard to make writing Windows Store apps as easy and smooth an experience as possible.

  Secondly, looking back to the days when Microsoft announced .NET, I think we've learned from that in the sense that we no longer promote a single technology to rule them all. We've made the mistake with .NET which lead to unrealistic expectations what .NET would deliver. I believe the .NET platform is the most productive development platform out there (otherwise I wouldn't work here) but I also believe it's not for everybody. Different tasks require different tools. And someone needs to write the CLR as well

  Rest assured that .NET isn't going away any time soon. You don't need to take my word for it -- just think of all the products Microsoft offers that are written in managed code.

  For platforms like Windows the key is offering choice. Some might have a strong web background with JavaScript. Others come from the native world and prefer C/C++. Others are .NET developers.

  My advice: ignore marketing and choose what you feel comfortable with and what gets the job done best.

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