What is the preferred naming convention for Func method parameters?

Question

I admit that this question is subjective but I am interested in the view of the community. I have a cache class that takes a cache loader function of type Func

Answer 1

There are precedents for using a noun in the Framework, e.g.

Enumerable.Average(this IEnumerable source, Func selector)

Enumerable.Count(this IEnumerable source, Func predicate)

Enumerable.GroupBy(this IEnumerable source, Func keySelector, Func elementSelector)

ConcurrentDictionary.GetOrAdd(TKey key, 
            Func valueFactory);

The noun is often an appropriate verb with an agentive suffix.

In your example I would use something like loader or possibly valueFactory. I personally don't like cacheLoader because presumably it's the caller rather than the delegate that does the work of inserting in the cache.