Recently in C# Category

XSLT isn't the best language for string processing, but it (XPath actually) has a very handy pair of substring functions: substring-before() and substring-after(). I used to write XSLT a lot and always missed them in C# or Java. Yes, C# and Java have indexOf() and regex, but indexOf() is too low-level and so makes code more complicated than it needs to be, while regular expressions is overkill for such simple, but very common operation.

Anyway, as an exercise in C# 3.0 I built these string extension functions following XPath 1.0 semantics for the substring-before() and substring-after(). Now I can have clean nice

arg.SubstringAfter(":")

instead of ugly

arg.Substring(arg.IndexOf(":")+1)

and shorter and more natural than

StringUtils.SubstringAfter(arg, ":")

Well, I missed MVP Summit this year, so while fellow MVPs enjoying together in Redmond I'm playing with C# 3.0 at home. And I'm in the process of Ruby learning, so what I spotted immediately is the lack (correct me if I'm wrong) of Each() and Map() support in .NET 3.5 collections.

In Ruby you can apply a block of code to each element in a collection using very elegant each() method:

[1,2,3].each { |item| puts item*item }

Each() method is basically a Visitor pattern implementation. I wonder why no such handy method exists in .NET 3.5? Dozens and dozens of new extension methods on collections covering every single aspect of collection manipulation from filtering to aggregation, but no basic functional programming facilities like Each() and Map()? Probably whoever at Microsoft decided foreach loop is still preferable solution for processing each element in a collection. That's what foreach does and does well.

I just started coding some real application with C# 3.0 (this is my favorite way of learning things) and immediately I can say I love it. C# 3.0 is going to be the best C# version ever. For me personally C# 1.0 was "hey look, kinda Java for Windows", C# 2.0 was "finally generics" and C# 3.0 is "wow, that's cool!".

Anyway, how do you check if a regular unsorted array contains particular element? Loop over elements checking each? Boring imperative crap.  C# 3.0 provides nice declarative solution via Contains<T>(this IEnumerable<T>, <T> value) extension method:

Remember that catchy RubyCLR motto?

Now C# (Anders Hejlsberg) is playing catch up talking about automatic properties:

public string Bar { get; set; }

private string foo; 
public string Bar 
{ 
    get { return foo; } 
    set { foo = value; } 
}