Patterns

Value Objects in F#

Jun 23rd

Posted by dan in F#

1 comment

Value Objects are objects that can be shared across different parts of a program. This can have great benefits in performance. Because  the objects are shared it is very important for value objects to be immutable. If value objects are not immutable then any part of the program can change the values and all the other parts can do calculation with erroneous data.

One of my goals was to make immutable objects in F# to take advantage of parallelization and automatic compiler optimizations:


type City(Name:string, X: float, Y:float) =

member t.Name = Name

member t.X = X

member t.Y = Y

type NeighborCities(city1:string, city2:string) =

member x.fromCity = city1

member x.toCity = city2

Objects created in this manner in F# are immutable. Even when they are accessed in other projects outside their definition, their members are read-only. This was specially helpful on the distributed traveling salesman problem I built last year.

Unitiy IOC

Feb 11th

Posted by dan in Best practice

2 comments

Basically, with Unity, I ended up writing something like this (simplified version) :

IUnityContainer container = new UnityContainer();

container.RegisterType<IRiskRepository, RiskRepository>();

string conn = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;

container.Configure<InjectedMembers>().ConfigureInjectionFor<RiskRepository>(new InjectionConstructor(conn));

UnityControllerFactory factory = new UnityControllerFactory(container);

ControllerBuilder.Current.SetControllerFactory(factory);

Unity turned out to work very well. I was able to save a lot of lines of code and it is greatly improving the testability of the dynamic modules I am using on the mock project architecture. Also, it was easy to set up. Its a good alternative to the other more popular IOC.