Extension interface patterns

Question

The new extensions in .Net 3.5 allow functionality to be split out from interfaces.

For instance in .Net 2.0

public interface IHaveChildren {
    str         


        

Answer 1

One problem I can see is that, in a large company, this pattern could allow the code to become difficult (if not impossible) for anyone to understand and use. If multiple developers are constantly adding their own methods to existing classes, separate from those classes (and, God help us all, to BCL classes even), I could see a code base spinning out of control rather quickly.

Even at my own job, I could see this happening, with my PM's desire to add every bit of code that we work on to either the UI or the data access layer, I could totally see him insisting on 20 or 30 methods being added to System.String that are only tangentially-related to string handling.