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SplayTreeMap<K, V> class

A Map of objects that can be ordered relative to each other.

The map is based on a self-balancing binary tree. It allows most operations in amortized logarithmic time.

Keys of the map are compared using the compare function passed in the constructor, both for ordering and for equality. If the map contains only the key a, then map.containsKey(b) will return true if and only if compare(a, b) == 0, and the value of a == b is not even checked. If the compare function is omitted, the objects are assumed to be Comparable, and are compared using their Comparable.compareTo method. Non-comparable objects (including null) will not work as keys in that case.

To allow calling operator [], remove or containsKey with objects that are not supported by the compare function, an extra isValidKey predicate function can be supplied. This function is tested before using the compare function on an argument value that may not be a K value. If omitted, the isValidKey function defaults to testing if the value is a K.

Mixed in types

Constructors

SplayTreeMap([int compare(K key1, K key2), bool isValidKey(dynamic potentialKey) ])
SplayTreeMap.from(Map other, [ int compare(K key1, K key2), bool isValidKey(dynamic potentialKey) ])
factory
Creates a SplayTreeMap that contains all key/value pairs of other. [...]
SplayTreeMap.fromIterable(Iterable iterable, { K key(dynamic element), V value(dynamic element), int compare(K key1, K key2), bool isValidKey(dynamic potentialKey) })
factory
Creates a SplayTreeMap where the keys and values are computed from the iterable. [...]
SplayTreeMap.fromIterables(Iterable<K> keys, Iterable<V> values, [ int compare(K key1, K key2), bool isValidKey(dynamic potentialKey) ])
factory
Creates a SplayTreeMap associating the given keys to values. [...]
SplayTreeMap.of(Map<K, V> other, [ int compare(K key1, K key2), bool isValidKey(dynamic potentialKey) ])
factory
Creates a SplayTreeMap that contains all key/value pairs of other.

Properties

isEmptybool
read-only, override
Returns true if there is no key/value pair in the map.
isNotEmptybool
read-only, override
Returns true if there is at least one key/value pair in the map.
keysIterable<K>
read-only, override
The keys of this. [...]
lengthint
read-only, override
The number of key/value pairs in the map.
valuesIterable<V>
read-only, override
The values of this. [...]
entriesIterable<MapEntry<K, V>>
read-only, inherited
The map entries of this.
hashCodeint
read-only, inherited
The hash code for this object. [...]
runtimeTypeType
read-only, inherited
A representation of the runtime type of the object.

Methods

addAll(Map<K, V> other) → void
override
Adds all key/value pairs of other to this map. [...]
clear() → void
override
Removes all pairs from the map. [...]
containsKey(Object key) → bool
override
Returns true if this map contains the given key. [...]
containsValue(Object value) → bool
override
Returns true if this map contains the given value. [...]
firstKey() → K
Get the first key in the map. Returns null if the map is empty.
firstKeyAfter(K key) → K
Get the first key in the map that is strictly larger than key. Returns null if no key was not found.
forEach(void f(K key, V value)) → void
override
Applies f to each key/value pair of the map. [...]
lastKey() → K
Get the last key in the map. Returns null if the map is empty.
lastKeyBefore(K key) → K
Get the last key in the map that is strictly smaller than key. Returns null if no key was not found.
putIfAbsent(K key, V ifAbsent()) → V
override
Look up the value of key, or add a new value if it isn't there. [...]
remove(Object key) → V
override
Removes key and its associated value, if present, from the map. [...]
addEntries(Iterable<MapEntry<K, V>> newEntries) → void
inherited
Adds all key/value pairs of newEntries to this map. [...]
cast<RK, RV>() → Map<RK, RV>
inherited
Provides a view of this map as having RK keys and RV instances, if necessary. [...]
map<K2, V2>(MapEntry<K2, V2> transform(K key, V value)) → Map<K2, V2>
inherited
Returns a new map where all entries of this map are transformed by the given f function.
noSuchMethod(Invocation invocation) → dynamic
inherited
Invoked when a non-existent method or property is accessed. [...]
removeWhere(bool test(K key, V value)) → void
inherited
Removes all entries of this map that satisfy the given predicate.
toString() → String
inherited
Returns a string representation of this object.
update(K key, V update(V value), { V ifAbsent() }) → V
inherited
Updates the value for the provided key. [...]
updateAll(V update(K key, V value)) → void
inherited
Updates all values. [...]

Operators

operator [](Object key) → V
override
Returns the value for the given key or null if key is not in the map. [...]
operator []=(K key, V value) → void
override
Associates the key with the given value. [...]
operator ==(dynamic other) → bool
inherited
The equality operator. [...]

© 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
https://api.dart.dev/stable/2.5.0/dart-collection/SplayTreeMap-class.html