Loyc.Collections.AListStatisticTrackerBase< K, T, TSummary > Class Template Reference

Base class that helps efficiently keep track of statistics about the contents of one or more AListBase{K, T} objects (including derived classes such as AList, BList, BDictionary and BMultiMap). Usually you'll use one of the derived classes instead, e.g. AListSumTracker{K,T}. More...

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Source file:

• /Core/Loyc.Utilities/Collections/AListStatisticTracker.cs

Inheritance diagram for Loyc.Collections.AListStatisticTrackerBase< K, T, TSummary >:

Remarks

Base class that helps efficiently keep track of statistics about the contents of one or more AListBase{K, T} objects (including derived classes such as AList, BList, BDictionary and BMultiMap). Usually you'll use one of the derived classes instead, e.g. AListSumTracker{K,T}.

Template Parameters

K	Key type of the AListBase
T	Value type of the AListBase
TSummary	Type of value that will be derived from the contents of the list(s)

This class keeps track of a "summary" of each node in each attached AList. It is assumed that there is some way to combine ("aggregate") summaries. For example, one common "summary" is the sum of a list of items, and multiple summaries can be combined simply by adding them.

This class can observe multiple lists at once and combine their results.

Public fields
IEnumerable< AListBase< K, T > >	AttachedLists => _roots.Keys
int	TotalCountInAttachedLists => _roots.Sum(pair => pair.Key.Count)
TSummary	Summary => GetSummary()

Public Member Functions
TSummary	GetSummary ()
Public Member Functions inherited from Loyc.Collections.Impl.IAListTreeObserver< K, T >
void	Detach (AListBase< K, T > list, AListNode< K, T >?root)
	Called when the observer is being detached from an AList. Detach(), unlike Attach(), is not paired with a call to RootChanged. More...
void	RootChanged (AListBase< K, T > list, AListNode< K, T >?root, bool clear)
	Called when the root of the tree changes, or when the list is cleared. Also called after Attach(), but not after Detach(). More...

Protected Member Functions
abstract TSummary	Summarize (AListLeafBase< K, T > data)
abstract TSummary	Aggregate (TSummary[] data)
TSummary	GetSummary (AListNode< K, T > node)

Protected fields
virtual TSummary	EmptyResult => Aggregate(Empty<TSummary>.Array)