C# design pattern suggestions

Question

I have a collection of objects. Out of this collection I need to search for an occurrence of an object using a number of conditions. ie.

Search using Condition 1

Answer 1

You could start with implementations of something like this for each filter:

public interface IFilter
{
    bool Matches(T itemToMatch);
}

For the sub-layer of filters (Condition 1...n) you could use a Composite 'all' filter like this; all of the IFilter implementations contained have to match for the composite to say it matches:

public class AllMatchingCompositeFilter : List>, IFilter
{
    public bool Matches(T itemToMatch)
    {
        return this.All(filter => filter.Matches(itemToFilter));
    }
}

...and for the top-level of filters (if Condition n doesn't match check Condition n+1) you could combine multiple AllMatchingCompositeFilters in an 'any' filter like this; it executes each of its IFilters in the order they were added and returns true if any of them match:

public class AnyMatchingCompositeFilter : List>, IFilter
{
    public bool Matches(T itemToMatch)
    {
        return this.Any(filter => filter.Matches(itemToFilter));
    }
}