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<TResult>, which it uses to retrieve a value from the database and store it in cache.

public static class Cache
{
    public TResult Get<TResult>(string cacheKey, Func<TResult> cacheLoader) 
    {
        // Implementation
    }
}

My question is: How should I name the function parameter?

• Should I name it like an object, e.g. cacheLoader?
• Should I name it like a method, e.g. loadResult?
• Should I explicitly refer to it as a function, e.g. cacheLoadFunction? (I don’t like this.)

I’m less interested in what I should name this particular function parameter and more interested in how you name function parameters in general. What say ye, Stack Overflow community?

Answer 1

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

Enumerable.Average<TSource>(this IEnumerable<TSource> source, Func<TSource, decimal?> selector)

Enumerable.Count<TSource>(this IEnumerable<TSource> source, Func<TSource, bool> predicate)

Enumerable.GroupBy<TSource, TKey, TElement>(this IEnumerable<TSource> source, Func<TSource, TKey> keySelector, Func<TSource, TElement> elementSelector)

ConcurrentDictionary<TKey,TValue>.GetOrAdd(TKey key, 
            Func<TKey, TValue> 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.