API Reference > bentleyjs-core > Collections Collections Specialized, customizable collection classes like priority queues. Classes Name Description Dictionary Maintains a mapping of keys to values. Entry An entry holds the key and value, and pointers to any older and newer entries. IndexedValue Associates a value of type T with an index representing its insertion order in an IndexMap IndexMap Maintains a set of unique elements in sorted order and retains the insertion order of each. LRUCache A mapping of a key/value pairs, where the size of the cache can be limited. LRUDictionary A LRUCache using a Dictionary as its internal storage, permitting custom key comparison logic. LRUMap A LRUCache using a standard Map as its internal storage. ObservableSet A standard Set that emits events when its contents change. OrderedSet A mutable ReadonlyOrderedSet. PriorityQueue A priority queue implemented as a heap array. ReadonlyOrderedSet A read-only equivalent of Set<T> that maintains its elements in sorted order as specified by a comparison function. ReadonlySortedArray A read-only view of an array of some type T sorted according to some user-supplied criterion. SortedArray Maintains an array of some type T in sorted order. Enumerations Name Description DuplicatePolicy Describes how duplicate values are handled when inserting into a SortedArray. Global Functions Name Description lowerBound Given a sorted array, computes the position at which the specified value should be inserted into the array so that the array remains sorted. partitionArray Partitions an array in-place according to some criterion, such that elements that fulfill the criterion are grouped in the lower shallowClone A CloneFunction that, given a value of type T, returns the same value. Interfaces Name Description DictionaryEntry Represents an entry in a Dictionary. EntryContainer The interface that must be satisfied by the underlying container type used by a LRUCache. Type Aliases Name Description CloneFunction ComputePriorityFunction Last Updated: 11 June, 2024