Last week I was asked to create a normalisation routine for the Msp spectra that my application uses. No worry if you don't know what Msp is. The thing is that it needed to find the maximum value in a collection of values and then do a calculation with that number over the other values in that collection.

First the value object.

In an ICollection(of T) you have a contains method to see if your collection has the requested element in it. But if you want to look for Multiple elements, you have to resort to making predicates (and we all know how ugly those get).

So why didn’t MS implement ContainsAny (OR) and/or ContainsAll (AND). I couldn’t think of a good reason, so I made them myself. They are perhaps a bit over easy and not very performance friendly but they work.

Here are the extension methods.

Problem

I keep forgetting that it needs the System.linq namespace to work. And I keep forgetting that it is not set by default on my projects. I try not to overuse linq but sometimes it is easy.

So what happened?

I was trying this: