What should the name of this class be?

Question

Naming classes is sometimes hard. What do you think name of the class should be?

I originally created the class to use as a cache but can see its may have other uses. Example code to use the class.

Dim cache = New NamePendingDictionary(Of String, Sample)

Dim value = cache("a", Function() New Sample())

And here is the class that needs a name.

' <summary> '
' Enhancement of <see cref="System.Collections.Generic.Dictionary"/>. See the Item property '
' for more details. '
' </summary> '
' <typeparam name="TKey">The type of the keys in the dictionary.</typeparam> '
' <typeparam name="TValue">The type of the values in the dictionary.</typeparam> '
Public Class NamePendingDictionary(Of TKey, TValue)
    Inherits Dictionary(Of TKey, TValue)

    Delegate Function DefaultValue() As TValue

    ' <summary> '
    ' Gets or sets the value associated with the specified key. If the specified key does not exist '
    ' then <paramref name="createDefaultValue"/> is invoked and added to the dictionary. The created '
    ' value is then returned. '
    ' </summary> '
    ' <param name="key">The key of the value to get.</param> '
    ' <param name="createDefaultValue"> '
    ' The delegate to invoke if <paramref name="key"/> does not exist in the dictionary. '
    ' </param> '
    ' <exception cref="T:System.ArgumentNullException"><paramref name="key" /> is null.</exception> '
    Default Public Overloads ReadOnly Property Item(ByVal key As TKey, ByVal createDefaultValue As DefaultValue) As TValue
        Get

            Dim value As TValue

            If createDefaultValue Is Nothing Then
                Throw New ArgumentNullException("createValue")
            End If

            If Not Me.TryGetValue(key, value) Then

                value = createDefaultValue.Invoke()
                Me.Add(key, value)

            End If

            Return value

        End Get

    End Property

End Class

EDIT: On Abel's advice I've named the class ValueCache.

Answer 1

In general, it's best to name a class after its intended usages. If users later find that another usage is possible or feasible, don't run off renaming your class. A reason to rename your class should only be to make its intended use clearer.

(edit) Others have commented on new names, like CacheManager, DeferredCache, LazyCollection, AssignedValueMap etc. If the original intention is very generic, use such names. If the intended use is more specific, name it such: CookiesCache, UsersList etc.

If you find yourself in the situation where you have a generic use case for an otherwise specific class, create a more general base class, with a general name, and use a specific subclass for the specific (original) use case. That's what OO is about ;-)

Answer 2

Call this class CacheManager and DO NOT put other functionaities in it.

Answer 3

You could call it a LazyDictionary, since items may not be initialized until they are needed :)

What is createDefaultValue? Is this initialized as part of the constructor?

Answer 4

I think as Abel suggested Map is a good term to use. I would consider naming the class something like AssignedValueMap and then use more specific variable names to make clear how you're using the AssignedValueMap in each case. So where you're using it for pending names I'd declare the associated variable as Dim pendingNamesMap = New AssignedValueMap(Of String, Sample).