Archives
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Upcoming Functional Programming/F# Talks
Well, I certainly have an ambitious May schedule ahead of me. Most of course will be revolving around functional programming and F# as it seems to be finally catching on. I've been noticing a bunch from the Java and Ruby communities becoming interested in such things as Scala, Haskell, OCaml, Erlang and F#. I was rather heartened by this as some in the Ruby world like here and here coming back to the static world for ways of representing data and functions in different ways. Of course Lisp and Scheme (IronLisp and IronScheme) still manages to eek in the rebirth, but still remains on the outside.
I will be speaking at the Northern Virginia Code Camp on May 17th for a total of two topics:
- Improve your C# with Functional Programming and F# concepts
Learn how .NET 3.5 takes ideas from Functional Programming and how you can apply lessons learned from it and F# respectively.
- Introduction to Functional Programming and F#
Come learn about functional programming, an older paradigm that Object Oriented Programming, and the ideas around it. This talk will cover the basics including high-order functions, functions as values, immutability, currying, pattern matching and more. Learn how to mesh ideas from functional programming with imperative programming in F# and .NET.
So, if you're in the DC area, go ahead and register here and show your support for the community.
Also, I will be taking some time to spend up in Philadelphia this month at the next Philly ALT.NET meeting to also talk about F#. Still ironing out the details on that one in regards to the DC ALT.NET meeting in May. Either way, should be a good time!
- Improve your C# with Functional Programming and F# concepts
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Making Spec# a Priority
During ALT.NET Open Spaces, Seattle, I spent a bit of time with Rustan Leino and Mike Barnett from the Spec# team at Microsoft Research. This was to help introduce Design by Contract (DbC) and Spec# to the ALT.NET audience who may not have seen it before through me or Greg Young. I covered it in detail on my old blog here.
Spec# at ALT.NET Open Spaces, Seattle
As I said before I took a bit of time during Saturday to spend some time with the Spec# guys. I spent much of the morning with them in the IronRuby session explaining dynamic languages versus static ones. They had the session at 11:30, the second session of the day, in direct competition with the Functional Programming talk I had planned with Dustin Campbell. Greg was nice enough to record much of the session on a handheld camera and you can find that here. It's not the best quality, but you can understand most of it, so I'm pretty happy.
The things that were covered in this session were:
- Spec# overview
- Non-null Types
- Preconditions
- Postconditions
- Invariants
- Compile-Time checking versus Runtime checking
- Visual Studio Integration
Scott Hanselman also recorded a session with the Spec# guys for Episode 128. This is a much better interview than on DotNetRocks Episode 237 that Rustan did last year. This actually gets into the technical guts of the matter in a much better way, so go ahead and give it a listen. I was fortunate enough to be in the room at the time to listen.
The New Release
Mike and Rustan recently released a new version of Spec# back on April 11th so now Visual Studio 2008 is supported. You must remember though, this is still using the Spec# compiler that's only C# 2.0 compliant. So, anything using lambdas, extension methods, LINQ or anything like that is not supported. As always, you can find the installs here.
As with before, both the Spec# mode (stripped down mode) and C# mode are supported. What's really interesting is the inferred contracts. From an algorithm that Mike and Rustan worked on, they have the ability to scan a method to determine its preconditions and postconditions. It's not perfect, but to have that kind of Intellisense is really powerful.
What you can see is that the GetEnumerator method ensures that the result is new. Keep in mind, result is a keyword which states what the return value is for a method. It also says that the owner of IEnumerator will be the same as before. Object ownership is one of the more difficult things to comprehend with Spec# but equally powerful.
Another concept that's pretty interesting is the ability to make all reference types non-null by default in C# or in Spec# modes. Instead of having to mark your non-null types with an exclamation mark (!), instead you can mark your nullable types with a question mark (?) much as you would with the System.Nullable<T> generic class. All it takes is the flip of a switch in Spec#:
Or in the C# mode:
And then you have all the Spec# goodness.
Why It's Important
So, why have I been harping on this? To be able to express DbC as part of my method signature is extremely important to me. To be able to express my preconditions (what I require), postconditions (what I ensure), my invariants (what state will change) is a pretty powerful concept. Not to mention, to enforce immutability and method purity is also a pretty strong concept, especially in the times of multi-core processing. More on that subject later.
Focus on Behaviors
What Spec# can bring to the table is the ability to knock out a bit of your unit tests. Now, I don't mean all of them, but what about the ones that check for null values? Are they valid if you already put in your method signature to require a non-null value or use the ! symbol to denote a non-null type? Those edge cases aren't really valid anymore. The ability to track your invariants is the same as well as your postconditions. Instead, what that does is frees you up to consider the behaviors of your code, what you should have been testing anyways.
Immutability
Immutability plays a big part in Spec# as well. To some extent, I'll cover more in a Domain Driven Design post, but instead will get some things out of the way here. Eric Lippert, C# team member, has stated that immutable data structures are the way of the future in C# going forward. Spec# can make that move a bit more painless? How you might ask? Well, the ImmutableAttribute lays out that explicitly. Let's do a simple ReadOnlyDictionary in Spec#, taking full advantage of Spec#'s attributes, preconditions and postconditions:
using System;
using System.Collections;
using System.Collections.Generic;
using Microsoft.Contracts;
namespace Microsoft.Samples
{
[Immutable]
public class ReadOnlyDictionary<TKey, TValue> : ICollection<KeyValuePair<TKey!, TValue>> where TKey : class
{
private readonly IDictionary<TKey!, TValue>! dictionary;
public ReadOnlyDictionary(IDictionary<TKey!, TValue>! dictionary)
{
this.dictionary = dictionary;
}
public TValue this[TKey! key]
{
get
requires ContainsKey(key);
{ return dictionary[key]; }
}
[Pure]
public bool ContainsKey(TKey! key)
{
return dictionary.ContainsKey(key);
}
void ICollection<KeyValuePair<TKey!,TValue>>.Add(KeyValuePair<TKey!, TValue> item)
{
throw new NotImplementedException();
}
void ICollection<KeyValuePair<TKey!,TValue>>.Clear()
{
throw new NotImplementedException();
}
[Pure]
public bool Contains(KeyValuePair<TKey!, TValue> item)
{
return dictionary.Contains(item);
}
[Pure]
public void CopyTo(KeyValuePair<TKey!, TValue>[]! array, int arrayIndex)
requires arrayIndex >=0 && arrayIndex < Count;
{
dictionary.CopyTo(array, arrayIndex);
}
[Pure]
public int Count
{
get
ensures result >= 0;
{ return dictionary.Count; }
}
[Pure]
public bool IsReadOnly
{
get
ensures result == true;
{ return true; }
}
[Pure]
bool ICollection<KeyValuePair<TKey!,TValue>>.Remove(KeyValuePair<TKey!, TValue> item)
{
throw new NotImplementedException();
}
[Pure]
public IEnumerator<KeyValuePair<TKey!, TValue>>! GetEnumerator()
{
return dictionary.GetEnumerator();
}
[Pure]
IEnumerator! System.Collections.IEnumerable.GetEnumerator()
{
return dictionary.GetEnumerator();
}
}
}
As you can see, I marked the class itself as immutable. But as well, I removed anything that might change the state of our dictionary, as well as mark things with non-null values. That's a little extra on top, but still very readable. I'll be covering more in the near future as it applies to Domain Driven Design.
Call to Action
So, the call to action is clear, make Spec# a priority to get it in C# going forward. Greg Young has started the campaign, so we need to get it moving!
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let Matt = CodeBetter + 1
Joining the CodeBetter Community....
#light
type FullName = string * string
let FullNameToString (name : FullName) =
let first, last = name in
first + " " + last
let blogger = FullNameToString("Matthew", "Podwysocki")
I'm pretty excited to be joining the CodeBetter gang after following for so many years. I want to thank Jeremy Miller, Brendan Tompkins, Dave Laribee, Greg Young and others for welcoming me to the fold. No, this blog won't be going away, but instead will also serve as a host for my posts.
So Who Are You and Why Are You Here?
So, just to introduce myself, I work for Microsoft in the Washington DC area. I'm active in the developer community in whether it be in the .NET space, Ruby, or less mainstream languages (F#, Haskell, OCaml, Lisp, etc). I also run the DC ALT.NET group since the November timeframe of last year and helped plan the latest incarnation in Seattle.
The number one reason I'm here is to help better myself. Deep down, I'm a language geek with any of the aforementioned languages. I'm one of those who strives to learn a language every year, but not just learn it, let it sink in. That's really the key. Sure, I can learn a certain dialect, but it's not quite being a native speaker. That's how I can take those practices back to my other languages to try to apply lessons learned such as functional programming paradigms (pattern matching, currying, first order functions, etc).
I also have a pretty deep interest in TDD/BDD, Domain Driven Design and of course one of Greg Young's topics, messaging. Right now in the world of messaging, I think we're in a pretty important time in the development world when messaging, multi-threaded processing and such is going to be more mainstream and hopefully less hard than it is now.
I'm also a tinkerer at heart. I'm looking at testing frameworks to help make my TDD experiences easier. I'm looking at IoC containers to help make my system just a bit more configurable. I'll look at the tests to see how each one does what it is. That's the fun part about it.
I'm also on the fringe with such topics as Spec# and Design by Contract. I'd love nothing more than to see many of the things being done at Microsoft Research become a bit more mainstream and not just seen as a place where we might see something 10 years down the line. Topics such as Spec#, F# and others have real importance now and it's best to play with them, give them our feedback and such.
So What Do You Want From Me?
Here's the thing, since I'm always looking to better myself, I'll need your help along the way. I value your feedback along the way and hopefully we'll learn from each other. Now that this is out of the way, time for more serious topics...
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xUnit.net Goes 1.0 and Unit Testing F#
As I've said before on my previous blogs, I'm very much into F# and functional programming lately. With that, I'm still in the mode of TDD. Just because you enter a new programming paradigm, doesn't mean you throw away your XP and TDD roots. Instead, I find it just as valuable if not even more so when switching to a new model.
xUnit.net 1.0 Goes Live
As Brad Wilson said earlier this week, xUnit.net released version 1.0. You can read more about the announcement here. Since the RC3 timeframe, it was pretty much feature complete, so there hasn't been much change since that time. Instead, the focus was on polishing the existing functionality and including the integration with ASP.NET MVC, Resharper 3.1 and TestDriven.NET. The GUI runner, such as it is has been pretty limited, but ok for most purposes.
Many questions used to arise, why xUnit.net? Why do we need yet another framework out there? Why not just add onto the existing ones in the market? I think with the 1.0 release, the critics in this release to do things a bit differently than MbUnit and NUnit have approached things. For example, the Assert.Throws<TException>, not having to decorate the classes with [TestFixture] and a few other things come to mind as well as being very extensible. It's a smaller framework, but I really don't have a problem with that. With most of the other frameworks, I don't use half of it anyways.
So, why do I care as much as I do about this one over say others at the moment? Well, it's great that we have such choices in the market now. As Scott Hanselman said at ALT.NET Open Spaces, Seattle, he's a StructureMap, Moq and xUnit.net guy. I'll get into the reason shortly enough.
The Traditional Way
When you think of doing your unit or behavior tests, you often need a class and decorate with attributes, have a initialize and teardown and all that goodness. Since F# is considered a multi-purpose language, this works just fine. That's the beauty of F# and hopefully will drive its adoption into the marketplace. So, consider the following functions with the appropriate tests in a more traditional way such as NUnit within Gallio. I am trying out Gallio so that I can see how well it reacts to F# as well as just kicking the tires. I highly recommend you at least check it out.
Anyhow, back to the code. Let's take a simple example of a naive routing table through pattern matching, to see whether a call is allowed or not. Like I said, naive, but proves a point with pattern matching.
#light
#R @"D:\Program Files\Gallio\bin\NUnit\nunit.core.dll"
#R @"D:\Program Files\Gallio\bin\NUnit\nunit.framework.dll"
let FilterCall protocol port =
match(protocol, port) with
| "tcp", _ when port = 21 || port = 23 || port = 25 -> true
| "http", _ when port = 80 || port = 8080 -> true
| "https", 443 -> true
| _ -> false
open NUnit.Framework
[<TestFixture>]
type PatternMatchingFixture = class
[<Test>]
member x.FilterCall_HttpWithPort8888_ShouldReturnFalse() =
Assert.IsFalse(FilterCall "http" 8888)
[<Test>]
member x.FilterCall_TcpWithPort23_ShouldReturnTruee() =
Assert.IsTrue(FilterCall "tcp" 23)
end
Unfortunately of course for me, the Gallio Icarus Runner doesn't really work well for me at the moment with F# integration. Instead, I get all sorts of issues when doing so. This is where I get the large FAIL.
This seems to repeat itself unfortunately for the xUnit.net and MbUnit integration as well, so it's not quite ready for primetime in the F# space. Also, when I exit the application, there is a Gallio session runner that keeps running in memory and therefore I can't perform any builds. So, I have to manually go into Task Manager and kill the process. Not the best experience I've ever had... So, for now, the limited functionality in the xUnit.net GUI Runner works for me.
The More Functional Way
Instead, we see a lot of pomp and circumstance that we just don't need. In the functional world, a lot of the time, we don't want or need to create these classes just to test our functions. After all, most of what we do has no side effects or at least should be (and are code smells mostly if they are not, but that's another post for another time).
At the request of Harry Pierson, another F# aficionado and IronPython PM, talked to Brad and Jim Newkirk about adding static function unit test capabilities to xUnit.net. And sure enough, we now have them, so let's compress the above code into something that looks more like F#.
#light
#R @"D:\Tools\xunit-1.0\xunit.dll"
open Xunit
let FilterCall protocol port =
match(protocol, port) with
| "tcp", _ when port = 21 || port = 23 || port = 25 -> true
| "http", _ when port = 80 || port = 8080 -> true
| "https", 443 -> true
| _ -> false
[<Fact>]
let FilterCall_TcpWithPort23_ShouldReturnTrue () =
Assert.True(FilterCall "tcp" 23)
[<Fact>]
let FilterCall_HttpWithPort8888_ShouldReturnFalse () =
Assert.False(FilterCall "http" 8888)
So, as you can see, I compressed the code quite a bit from here. Since I'm doing functions and nothing more with just some basic pattern matching, this approach works perfectly. That's why I am a fan of this. Open up the GUI runner or just the ever popular console runner, and run it through and sure enough, we get some positive results.
The interesting thing to see upcoming is how well the TDD space will play in the functional programming space. I don't think it should be any different of an experience, but time will tell.
Where to Go?
From here, where do we go? Well, I'm sure the GUI Runner of xUnit.net will get better over time, but the Gallio folks are pushing for the Icarus Runner. Right now, only the xUnit.net runner works for me, so that's what I'm going to stick with at the moment.
An interesting thought occurred to me though. Are the unit tests we're doing mostly nowadays purely functional anyways? Would it make sense to test some C# code in F# to produce cleaner code? Not sure, but I like the idea of having that choice. Or even for that matter, writing my unit tests in Ruby for my staticly typed C# code. Within the .NET framework space, the possibilities are vast. And that's the really cool thing about it. But will we see an IronPython or IronRuby testing framework within the .NET space?
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ALT.NET Open Spaces Closing Day Recap
In my previous post, I talked about some of the happenings from the day two experience. Day three was only a half day with only two sessions. So, it was best to make the best of times anyhow. Once again, it snowed again, rather heavily at times, so nature's cruel joke on ALT.NET.
Impromptu Sessions
One of the best sessions was an impromptu session with Jeremy Miller on the StoryTeller tool and his future plans for it. If you're not familiar with it, it is a tool used to manage and create automated testing over the FitNesse Dot Net libraries and helps in an acceptance test driven development environment. Anyhow, a number of us managed to corner him at one point during the day and sure enough he had his laptop available. From there, we were able to encourage him to work on it some more as well as learn about where to go from where it is right now. Jeremy covers more about it here. Sometimes these impromtu sessions are some of the more valuable interactions to be had at events such as these.
More Video To Be Had
It seems that almost everyone had a camera at the event. Greg Young and Dave Laribee managed to capture a bit of the sessions on video. That's a great thing because I honestly wish I could have cloned myself and gone to more sessions. Hopefully more of this will be forthcoming. Dave posted Greg Young's fishbowl conversation on Architecture Futures which you can see here.
Other videos that are on this list are from John Lam's IronRuby session, Udi Dahan with ScottGu and Chad Myers talking about Microsoft and Open Source Software and so on. You can find them at the end of Greg's video.
Software Design Has Failed, What Can We Do About It?
Scott Koon, aka LazyCoder, convened with JP Boodhoo a session on how software design has failed us. This turned into a fishbowl conversation as well since there was a lot to be said. The basic points revolved around the large amount of software failures. What causes them? Are they technological issues? People issues? Politics? Many people brought their opinions to bear, and it was interesting that the point that I brought is that at the end of the day, customer satisfaction is the metric that matters. Are we listening to them? In the Agile methodology world, customer satisfaction is the only metric. Yes, we can talk about TDD/BDD, DDD and so on, but are we actually putting software into the hands of the user that they actually want?
I'm not forgetting of course the ideals around mentoring and helping make the team stronger. Those issues are important as well. Do we do pair programming? Do we hold brown bag sessions? All of those suggestions are key to helping grow a stronger team. But, also it helps grow the team as a more cohesive unit that's not afraid to ask questions, pair up and avoid flailing.
F# and Concurrency
Roy Osherove convened a session on concurrency and functional programming as the last topic I was going to attend. When we start to deal with multi-core environments, threading issues come to bear more frequently. Are we utilizing the CPUs to the maximum or are we still just sitting on that one thread, and barely using the machine to its capacity? Those are many of the issues we face. In Software Engineering Radio Episode 14, Ted Neward talks to this very point quite frankly that multi-threaded programming is hard. There are no two ways about it. But, when we talk about functional programming, some of that is solved. Why? Immutability by default is one of the key strong points of FP. Instead, you have to go out of your way to make a value to be mutable. Is this something we'll see in C# 4.0? Spec# has something to say about it. And once again, another topic for discussion. I keep putting these things on my plate...
Anyhow, Harry Pierson and I helped run this session. Harry had some of his parsing code that he has posted on his blog to show off. I think that did the trick well to show some advanced things such as high order functions, pattern matching, anonymous functions and so on. Instead, if you wish to learn more, I'll probably cover it here in some detail, but you can check chapter 13 of Don Syme's "Expert F#" book to learn more in the mean time.
Action Items
Some action items came up from this event that I think are rather important. Because ALT.NET is a community looking to improve itself, there are naturally some things that help. Here are a few that I can think of:
- Keep the conversation going
Just because the conference ended doesn't mean the conversations that started there have to.
- Start a local group
After the session was done, the altdotnet mailing list came alive with people wanting to create that ALT.NET groups like I did in DC, Brian Donahue did in Philly and Jeremy Jarrell did in Pittsburgh.
- Support the community
Ray Houston laid out a challenge for those who use Open Source products to donate to them. This doesn't mean only money, but time as well. Many projects are in need of some assistance, and all it takes is for someone to ask.
- Challenge Assumptions and Bring Change
It was said best during the conference "If you can't change your job, change your job". Don't let these discussions that happened here just stay there. Bring them to your work place, bring change for the better. Question why things are done the way they are.
Wrapping it Up
I'm glad to have been a part of this event in Seattle. It couldn't have been with a better bunch of people who are willing to better themselves, challenge themselves and their assumptions and bring change to the developer community. There was a lot to learn this past weekend and each conversation brought up a new angle. Until next time...
- Keep the conversation going
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ALT.NET Open Spaces, Seattle Day 2 Recap
In my previous installment of recapping the events from ALT.NET Open Spaces, Seattle, I covered pretty much the opening ceremonies as it were. The weather was definitely interesting the entire weekend. Who would believe that we had snow, hail and rain for most of the time we were there in the latter half of April? Mind you it didn't stick, but if you believe in God, there is something to be said of ALT.NET coming to town.
Coverage Galore
Jeffrey Palermo was gracious enough to capture the opening ceremonies on video for all to see. Here are some of the videos and they are well worth watching. Really gives you an idea of how to run a good Open Spaces. Doc did a wonderful job as a facilitator for the event. And yes, that's me in the black coat in the background setting up for the event.
- ALT.NET Open Spaces, Seattle - Part 1
An introduction by Doc on the meaning of Open Spaces
- ALT.NET Open Spaces, Seattle - Part 2
More introduction and the suggestion of topics. Everyone who submitted topics had to get in the middle of the room and declare their topic of interest.
- ALT.NET Attendees - Why Did You Come to ALT.NET?
Jeffrey interviews various attendees such as the some Microsofties (Scott Guthrie, Harry Pierson, Glenn Block, Don Smith), CodeBetter guys (Greg, Jeremy, JP Boodhoo, Ian Cooper), Scott Bellware, the Israelis (Udi, Roy, Justin and Ayende), Martin Fowler, John Osborn, Jim Shore, etc on what ALT.NET means to them and why they came.
So, as you can see from the videos it was a pretty diverse crowd. And, hey, we managed to get all of 5 women there too! Peter Laudati posted the schedule here which was initialed by all who wanted to see that particular discussion.
IronRuby Session
Since John Lam wasn't around on Friday for the topic submittal, I so graciously put his name in for him. Luckily he agreed so we were good to go for the first session. We didn't have any canned presentations which is nice. Instead, John focused more on how far IronRuby has yet to go. It was interesting that he is using the Rubinius specs in order to validate IronRuby. Also of note, it was pretty cool to see that Spec# has been used for the IronRuby compiler.
Covering Spec#
Unfortunately, the functional programming talk that I planned with Dustin Campbell was put right along side the Spec# talk, so I had to make a choice. I picked Spec# as it was the first Open Spaces they had done. As I said before, one of the major things I wanted to talk about was Spec# at ALT.NET. Both Greg Young and I were pretty interested in getting Rustan Leino and Mike Barnett to show off the technology to the masses. And what better way than to show a bunch of geeks like us this technology. Anyhow, Mike and Rustan did a really good presentation to show off Spec# to a mass audience. For those not familiar with Spec#, I did a whole series on this on my old blog here. Basically, the intent of Spec# is to provide Design by Contract specifications in your classes and have that exposed to the outside world. So, no more guessing about the preconditions, postconditions and invariants of your system, instead, we can be pretty explicit about it.
The problem that they are facing is that Spec# is not just an additive to the C# compiler, instead it's a separate compiler that is compliant with the C# 2.0 specification. The problem is that C# 3.0 introduces a few more items, albeit mostly syntactic sugar for the most part, and yet Mike is really one of the only guys doing the Spec# compiler. So, making it C# 3.0 compliant is a pretty daunting task. Instead, a future focus is on making language neutral pieces available to all .NET languages just as we saw briefly in the System.Core.dll assembly under the Microsoft.Contracts namespace. The point of inviting them was to help bring their cause to a wider audience. Anders Hejlsberg and Mads Torgersen need to put this on their mind as to how to incorporate, and I'll make sure it's widely known.
It was great to see Scott Hanselman quite excited about the technology and hopefully you'll see more of it from him soon. Also, stay tuned to InfoQ for more Spec# related items as well. I intend to cover things again shortly to talk about some other new things in Spec# as well as the new release. Stay tuned for that...
ASP.NET MVC
Phil Haack and Brad Abrams hosted a discussion on ASP.NET MVC which was pretty positive overall. There has been a number, around 5% that Microsoft has been throwing out there as a number of people that would be adopting ASP.NET MVC over traditional web forms. The audience was rightly skeptical of such a number and wish that they would cut it out. Instead, it could have the effect of scaring away people from adopting this framework as their choice for ASP.NET web applications. I can totally understand that the numbers could be there due to the ISV market which make controls for ASP.NET web forms which is something that the MVC framework doesn't support. Another request was to support open source javascript frameworks better. But overall, Phil and Brad were pretty receptive and it was an overall positive experience.
Are We Innovating?
Scott Hanselman convened a talk asking "Are We Innovating or Are We Just Porting?" in which that very question was asked. If you look at the open source frameworks that exist within the .NET space, it's not hard to see what he's talking about:
- JUnit => NUnit, MbUnit, xUnit.net
- Hibernate => NHibernate
- Spring => Spring.NET
- Ruby on Rails => MonoRail
- jMock => NMock, Rhino Mocks, Moq
- Ant => NAnt, MSBuild
- And the list goes on...
To Be Continued...
- ALT.NET Open Spaces, Seattle - Part 1
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DC ALT.NET Meeting 4/23/2008 - Jay Flowers and CI Factory
Now that we've somewhat recovered from ALT.NET Open Spaces, Seattle, it's time for another DC ALT.NET meeting. I'm currently finishing up my wrapups for Seattle still and I'm sure I have months worth of material from there. Anyhow, this time Jay Flowers will be talking to us about Continuous Integration and CI Factory which was postponed from last month due to schedule conflicts. As always we have the first hour or whenever the conversation ends for our main topic and the rest is Open Spaces. Food will be served as well.
Below are the details for the meeting:
Time:
4/23/2008 - 7PM-9PM
Location:
2201 Wilson Blvd
Arlington, VA 22201
Parking/Metro:
Best parking on N. Veitch St
Courthouse Metro the best bet
As always you can find out more by joining the mailing list here. Hope to see a great crowd there and to continue some of the great discussions that were held in Seattle. Until next time...
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ALT.NET Open Spaces, Seattle Day 1 Recap
ALT.NET Open Spaces, Seattle has come to a close. What a great time it was and it met every expectation if not exceeded them. Currently I'm in the Seattle airport waiting for my flight home which just got re-arranged. Anyhow, I'd like to wrap up my thoughts for the first day of the event.
Setting It Up
I arrived one day early for the event to make sure we were set up appropriately. I was able to meet up with Dave Laribee, Glenn Block, Scott Bellware, Jeremy Miller, Greg Young, Scott C Reynolds, Ray Lewallen, Patrick Smacchia and others. Everyone was already burned out from the MVP Summit, so I wasn't sure how well people would be for the event. But it was great to talk to Sam Gentile and I'm glad he's back in the fold with ALT.NET as he announced earlier last week here.
Even though a lot of people were tired, we had plenty of help to set up for the event. Of course the joke is that "How many ALT.NETers does it take to go to Costco?"...
Kicking It Off
One couldn't ask for a more prepared and outstanding facilitator in Steven "Doc" List. What an amazing job he did to bring the Open Spaces together. The event started with a description of Open Spaces Technology. if you're not familiar with the Open Spaces, Technology Format, here are the four basic principles:
- Whoever comes are the right people
- Whatever happens is the only thing that could have
- Whenever it starts is the right time
- When it's over, it's over
The Sessions
I met with Mike Barnett from the Spec# team who was one of the many people I had invited to this event. Spec# as you may have figured from my blog is a passion of mine. It is one of my goals to publicize it enough and to make sure that people are aware of this wonderful technology that the product teams such as Mads Torgersen and Anders Hejlsberg notice. Anyhow, Mike went up and announced a session on Spec# and static verification. I'll cover more of that in subsequent posts again. Start your letter writing campaigns now!
Dustin Campbell also was in attendance and he and I chatted about F# and doing a session on functional programming and F#. It was going to be a great session, but unfortunately when the schedule was finalized, I couldn't possibly attend the Spec# and functional programming and F# talk. I was a little disappointed by that, but luckily Roy Osherove suggested a talk about "Concurrency and Functional Programming" which I was more than willing and able to help out on. I also pulled Harry Pierson, the new Program Manager for IronPython to help in such a session.
Since John Lam wasn't in attendance that night, I volunteered him for a session on IronRuby and the DLR which he was more than happy to oblige. We scheduled that for the first session on Saturday. I'll cover each of these in detail in subsequent posts.
The Fishbowl
From there, we went to a fishbowl style conversation in which there are a number of chairs in the middle of the room. There must be all but one of the chairs filled at any given time. Any person may in turn come and take a seat and another person must leave to keep the balance. The discussion started with Scott Hanselman, Ted Neward, Charlie Calvert and Martin Fowler talking about the Polyglot Programmer. Ted Neward couldn't be there for the whole event, unfortunately as he was also doing No Fluff Just Stuff this weekend as well with Venkat Subramaniam, Neal Ford and others. Luckily I got some time to talk to Ted about some F# related items as well as his upcoming trip to Reston, VA for No Fluff Just Stuff next weekend. So, if you're in the area and interested in seeing Ted and Venkat, that's the place to go! But anyways, the event was great and a lot of people pitched in. There are so many to name, I'd just run out of space.
To Be Continued....
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Off to Seattle and ALT.NET Open Spaces, Seattle
Well, the day has finally come where I'm heading to ALT.NET Open Spaces, Seattle. It's been a long time of planning for this day with all the other guys mentioned on the site. The weather's not looking so great with a possibility of snow on Saturday. Not looking forward to that part as I'm leaving sunny, beautiful Washington DC where it is around 75F or so right now.
I hope to be live blogging much of the event, well as much as I can. I you're on Twitter, you can follow me at mattpodwysocki. Looking forward to seeing everyone there!
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NOVARUG with Dave Thomas (PragDave) Recap
Last night I attended the Northern Virginia Ruby Users Group (NovaRUG) meeting in Reston last night with Dave Thomas (PragDave) and Chad Fowler. It was a completely packed house and the temperatures were a bit hight in the room, but it was well worth the sweating to attend.
Paul Barry presented first on Merb and gave a really good demonstration of some of the capabilities in comparison to Ruby on Rails. If you're not familiar with Merb, it is a lightweight Model View Controller framework written in Ruby. It was written by Ezra Zygmuntowicz in response to trying and giving up on making Ruby on Rails thread safe. You can find his presentation materials here.
It was mentioned that there will be a Ruby conference in the Northern Virginia area upcoming I'd like to see if we can get some IronRuby in there instead of all those Java guys with JRuby. We'll see what happens, but for right now, everything seems to be in flux. Stay tuned!
Next up, Dave Thomas talked about the Ruby object model with a very good presentation. Below you can find some of my pictures I took from the event. Forgive the quality of the images, but you can tell that it was a crowded place! Anyhow, it was a really good talk about the object model, how the scoping of self and the resolution of classes and methods are done deep down in Ruby. It was an excellent presentation and I was definitely excited by his passion for the community and the technology.
First we have Dave talking about the inheritance chain of Ruby objects.
Then here's Dave talking about the method resolution.
I had a chance to chat with Dave afterwards on F# as he has been looking into OCaml lately, where F# got most of its functionality from. It's his hope that F# succeeds and I ultimately think it will. So, I told him to give it a try. Anyhow, it was a great night and good to reach out to the community. The DC area has a pretty rich community of .NET, Ruby and Java programmers that's really refreshing to see. Until next time...
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Metaprogramming in F#
Tonight I will be heading to the Northern Virginia Ruby Users Group (NoVARUG) meeting tonight with Dave Thomas (PragDave) talking about metaprogramming in Ruby. Should be a great time and I'm sure it will be full tonight. For those interested in some introduction to metaprogramming in Ruby, here's a good link to help get you started.
Metaprogramming in F#?
One of the many things that has interested me in F# is that it was originally written as a language to write other languages. This of course leads me to a discussion of F# and metaprogramming. Is it a fit? There are a couple of links well worth visiting and then at a future date, we'll come back to the subject.
Before the links, most of the language oriented stuff comes from quotations. Quotations are a little block of code which turns a particular piece of code into an expression tree. This language tree can then be transformed, optimized and even compiled into different languages. There are two types of these quotations, raw and typed. Typed Quotations contain static typing information whereas the raw do not. For a good introduction to these, check out Tomas Petricek's post here.
- Leveraging Meta-Programming Components with F# - Don Syme
Talks about F# with Quotations and LINQ expressions for expressing metaprogramming in F#
- F# metaprogramming and classes - Tomas Petricek
Talks about Class Quotations and basic metaprogramming capabilities in F# and its limitations
- Leveraging Meta-Programming Components with F# - Don Syme
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Adventures in F# - F# 101 Part 8 (Mutables and Reference Cells)
class Program
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ALT.NET on DotNetRocks and the Community
Dave Laribee and Jeremy Miller recently recorded an episode on DotNetRocks and was just posted today. Episode 333 "It's the ALT.NET Show" can be found here. It's a great show that explains ALT.NET for those who may not really know what it is outside of some of the arguments on the altdotnet mailing list. This includes discussions on open source frameworks, agile practices, refactoring and so on.
It's great to see the reaction from this show at least from my perspective. To see the job we're doing from Josh Holmes, Glenn Block, me and others from within to reach out and also present ideas and bridge the gaps. It's been very rewarding to be a part of that.
We're only just a few days away from ALT.NET Open Spaces, Seattle. All of those who are attending should have received a notice of such this morning. I'll be arriving in Seattle on Thursday afternoon to help set up for the event so if anyone wants to hang out beforehand let me know.
Bringing It To The Community
Anyhow, this weekend I did my best to bring some of those ALT.NET practices to the CMAP Code Camp and we had a pretty good turnout. This time I talked about refactoring to patterns, dependency injection and inversion of control containers. I'm hoping to do the same for the Northern Virginia Code Camp coming up on May 17th. Brian Donahue has been rather successful doing so with the Philly Code Camps as well. That reminds me that I'm coming up there in mid-May to do an F# session. Should be a fun time.
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CMAP Code Camp Wrap Up - Dependency Injection and IoC Containers
I really enjoyed speaking at this past weekend's CMAP Code Camp. I hope you all enjoyed my presentation on "Loosen Your Dependencies with Dependency Injection and Inversion of Control Containers". It was a great discussion to have with everyone and I like to learn there as much as I teach.
I also enjoyed teaming up with Scott Allen on his "A Gentle Introduction to Mocking" where we talked about mocks versus stubs, test pattens and mock frameworks such as Rhino Mocks and Moq. Hopefully we'll be doing some more ping-pong sessions in the future.
Once again, I'd like to plug my DC ALT.NET group that I run. Our next meeting is scheduled for April 23rd and the topic will be Continuous Integration with Jay Flowers. We'll announce the location shortly for our group. You can go ahead and sign up for our mailing list here.
Anyhow, here are some resources that can help point you in the right direction. This includes articles, blogs and such that I find will be useful in your journey to better understand these things:
- Articles
- Blogs
- Books
If you note, I my code uses the following products in order to get it to run:
- ASP.NET MVC Preview 2
- xUnit.net
- Castle Windsor
- StructureMap
- Unity Application Block
- Unity Community Contributions
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Unity Community Contributions and Interception
public delegate IMethodReturn InovkeHandlerDelegate(IMethodInvocation call,
GetNextHandlerDelegate getNext);
public delegate InovkeHandlerDelegate GetNextHandlerDelegate();
public interface IInterceptionHandler
{
IMethodReturn Invoke(IMethodInvocation call,
GetNextHandlerDelegate getNext);
}
}
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xUnit.net RC3 Just Released
Well, Brad Wilson and Jim Newkirk must really be busy lately. After I talked about the release of xUnit.net RC2, just today, Brad announced the release of RC3. As always, you can find the latest bits here. This fixes a number of bugs and adds CruiseControl.NET and ASP.NET MVC Preview 2 support as well in addition to the Resharper 3.1 and TestDriven.NET support. For more information about it, check out Brad's post here. More or less, they are feature complete for version 1.0 and the only that I think really is needed at this point is a decent GUI runner and that's well acknowledged as something they are working on. Visual Studio integration would be nice as well...
If you were in attendance at last night's RockNUG appearance, all tests for my demos were using xUnit.net, so I am actively using it right now and will be for my CMAP Code Camp appearance this weekend. However, I did not show the GUI runner because, well, it's not there yet, and instead, the console runner works just fine, thank you. So, go ahead and pick up the latest bits and give the team feedback!
For my other posts in this series, check them out here:
One last note regarding Brad, he was recently interviewed by Scott Swigart and Sean Campbell over at How Software Is Built and gives some interesting insights in the open source world inside and outside Microsoft and his contributions to it. Very good interview and well worth the time to read.
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RockNUG IoC Container Presentation Wrapup
I want to thank the fine folks at the Rockville .NET Users Group (RockNUG) and Dean Fiala for giving me the opportunity to speak last night. It was a record crowd last night, so I'm glad that people were interested in Loose Coupling, Design Patterns, Test Driven Development, Behavior Driven Development and Inversion of Control containers. I hope everyone got some good information, and if not interested in using containers, design patterns and such, at least know they exist and have their use. Based on the feedback I've already received, it was warming and why I like presenting at user groups, so that both of us can learn.
Once again, I'd like to plug my DC ALT.NET group that I run. Our next meeting is scheduled for April 23rd and the topic will be Continuous Integration with Jay Flowers. We'll announce the location shortly for our group. You can go ahead and sign up for our mailing list here.
Anyhow, here are some resources that can help point you in the right direction. This includes articles, blogs and such that I find will be useful in your journey to better understand these things:
- Articles
- Blogs
- Books
-
NoVARUG Meeting April 16th - Dave Thomas (PragDave)
The Northern Virginia Ruby Users Group (NoVARUG) will be holding their next meeting next week with a special speaker in Dave Thomas (PragDave). Dave is in town teaching Advanced Rails Studio in Reston and will be kind enough to come talk about the Ruby Object model and how it facilitates metaprogramming.
The details are as follows:
Subject:
Dave Thomas - The Ruby Object Model and Metaprogramming
Date:
April 16th, 2008 - 7-9PM
Location:
FGM Inc
12021 Sunset Hills Road
Suite 400
Reston, VA 20190
Hope to see a good crowd there! I know I'm very interested in this subject and hope to dive deeper soon. That reminds me I need to do some of metaprogramming in F# as well.
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Unity 1.0 Released into the Wild
As Chris Tavares mentioned in his blog, Unity 1.0 has been released a couple of days earlier than the April 7th release date mentioned by Grigori Melnik earlier. Scott Densmore also announced this as well as working on porting the inteception from ObjectBuilder2 which I talked about earlier in some of my Unity and IoC containers posts. Looking forward to that post as we've shared some emails on the subject.
Would You Like To Know More?
For those looking for my posts on the matter, I've covered it quite extensively with the comparison to other IoC containers as well as IoC containers in general:
- IoC and Unity - Configuration Changes for the Better
Covers the latest configuration changes to allow for better constructor injection
- IoC and Unity - The Basics and Inteception
Covers the basics of an IoC container and inteception techniques
- IoC Container, Unity and Breaking Changes Galore
Covers the breaking changes made from the old Unity drop to the new one
- IoC Containers, Unity and ObjectBuilder2 - The Saga Continues
Managing instances and parameter mapping resolution
- IoC and the Unity Application Block Once Again
Setter Injection versus Constructor Injection and PostSharp4Unity
- IoC and the Unity Application Block - Going Deeper
Constructor Injection and comparing Unity with Castle Windsor
- IoC and the Unity Application Block
Covering ObjectBuilder and Unity Application Block
Anyhow, if interesting in more Unity content, check out David Hayden's Unity IoC and MVC screencast as well as others on the subject here.
Speaking of which, I'm going to be a busy man indeed with my upcoming speaking schedule on IoC containers, not necessarily Unity in particular, but all of them, the background and decoupling your applications. Here is the complete schedule for this month:
- RockNUG - April 9th
- CMAP Code Camp - April 12th
- CMAP Architecture SIG - April 15th
- IoC and Unity - Configuration Changes for the Better
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Relooking at xUnit.net RC2
using MVC_APPLICATION_NAMESPACE.Controllers; // This using directive needs to point to the namespace of your MVC project
-
Adventures in F# - F# 101 Part 7 (Creating Types)
#light
let coin = "heads", "tails"
let c1, _ = coin
let _, c2 = coin
print_string c1
print_string c2 -
Covering NUnit 2.4.7
#light
#R @"D:\Program Files\NUnit 2.4.7\bin\nunit.core.dll"
#R @"D:\Program Files\NUnit 2.4.7\bin\nunit.framework.dll"
open NUnit.Framework
let rec fib n =
match n with
| 0 | 1 -> 0
| n -> fib(n-2) + fib(n-1)
| n when n < 0 -> failwith "Cannot be less than zero"
[<TestFixture>]
let FibOfOneShouldReturnZero() =
let fibResult = fib(1)
Assert.AreEqual(fibResult, 0)
