CombinedMapView<K, V> class

Returns a new map that represents maps flattened into a single map.

All methods and accessors treat the new map as-if it were a single concatenated map, but the underlying implementation is based on lazily accessing individual map instances. In the occasion where a key occurs in multiple maps the first value is returned.

The resulting map has an index operator ([]) that is O(maps), rather than O(1), and the map is unmodifiable, but underlying changes to these maps are still accessible from the resulting map.

The length getter is O(M) where M is the total number of entries in all maps, since it has to remove duplicate entries.

Inheritance

• Object
• MapBase<K, V>
• UnmodifiableMapBase<K, V>
• CombinedMapView

Available extensions

• MapX

Constructors

CombinedMapView(Iterable<Map<K, V>> _maps)

Create a new combined view of multiple maps.

Properties

entries → Iterable<MapEntry<K, V>>

The map entries of this Map.

no setter, inherited

hashCode → int

The hash code for this object.

no setter, inherited

isEmpty → bool

Whether there is no key/value pair in the map.

no setter, inherited

isNotEmpty → bool

Whether there is at least one key/value pair in the map.

no setter, inherited

keys → Iterable<K>

The keys of this.

no setter, override

length → int

The number of key/value pairs in the map.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

values → Iterable<V>

The values of this Map.

no setter, inherited

Methods

addAll(Map<K, V> other) → void

This operation is not supported by an unmodifiable map.

inherited

addEntries(Iterable<MapEntry<K, V>> entries) → void

This operation is not supported by an unmodifiable map.

inherited

cast<RK, RV>() → Map<RK, RV>

Provides a view of this map as having RK keys and RV instances, if necessary.

inherited

clear() → void

This operation is not supported by an unmodifiable map.

inherited

containsKey(Object? key) → bool

Whether this map contains the given key.

inherited

containsValue(Object? value) → bool

Whether this map contains the given value.

inherited

forEach(void action(K key, V value)) → void

Applies action to each key/value pair of the map.

inherited

getOrCompute<T>(K key, T computation()) → T?

Available on Map<K, V>?, provided by the MapX extension

getOrDefault<T>(K key, T defaultValue) → T?

Available on Map<K, V>?, provided by the MapX extension

map<K2, V2>(MapEntry<K2, V2> transform(K key, V value)) → Map<K2, V2>

Returns a new map where all entries of this map are transformed by the given convert function.

inherited

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

putIfAbsent(K key, V ifAbsent()) → V

This operation is not supported by an unmodifiable map.

inherited

remove(Object? key) → V?

This operation is not supported by an unmodifiable map.

inherited

removeWhere(bool test(K key, V value)) → void

This operation is not supported by an unmodifiable map.

inherited

toString() → String

A string representation of this object.

inherited

update(K key, V update(V value), {V ifAbsent()?}) → V

This operation is not supported by an unmodifiable map.

inherited

updateAll(V update(K key, V value)) → void

This operation is not supported by an unmodifiable map.

inherited

withValue<T>(Object? key, ValueSetter<T> onValue) → void

Available on Map<K, V>?, provided by the MapX extension

withValueOrDefault<T>(Object? key, ValueSetter<T> onValue, T def) → void

Available on Map<K, V>?, provided by the MapX extension

Operators

operator ==(Object other) → bool

The equality operator.

inherited

operator [](Object? key) → V?

The value for the given key, or null if key is not in the map.

override

operator []=(K key, V value) → void

This operation is not supported by an unmodifiable map.

inherited