UnmodifiableMapFromIMap<K, V> class

The UnmodifiableMapFromIMap is a relatively safe, unmodifiable Map that is built from an IMap or another Map. The construction of the UnmodifiableMapFromIMap is very fast, since it makes no copies of the given map items, but just uses it directly.

If you try to use methods that modify the UnmodifiableMapFromIMap, like add, it will throw an UnsupportedError.

If you create it from an IMap, it is also very fast to lock the UnmodifiableMapFromIMap back into an IMap.

How does it compare to Dart's native Map.unmodifiable and UnmodifiableMapView?

Map.unmodifiable is slow, but it's always safe, because it is not a view, and actually creates a new map. On the other hand, UnmodifiableMapFromIMap and UnmodifiableMapView are fast, but if you create them from a regular Map and then modify that original Map, you will also be modifying the views. Also note, if you create an UnmodifiableMapFromIMap from an IMap, then it's totally safe , then it's totally safe because the original IMap can't be modified.

The only different between an UnmodifiableMapFromIMap and an UnmodifiableMapView is that UnmodifiableMapFromIMap accepts both a Map and an IMap.

Constructors

UnmodifiableMapFromIMap(IMap<K, V> imap): Create an unmodifiable Set view of type UnmodifiableSetView, from an iset.
UnmodifiableMapFromIMap.fromMap(Map<K, V> map): Create an unmodifiable Set view of type UnmodifiableSetView, from another Set.

Properties

entries → Iterable<MapEntry<K, V>>: The map entries of this.
no setterinherited
hashCode → int: The hash code for this object.
no setterinherited
isEmpty → bool: Whether there is no key/value pair in the map.
no setterinherited
isNotEmpty → bool: Whether there is at least one key/value pair in the map.
no setterinherited
keys → Iterable<K>: The keys of this.
no setteroverride
length → int: The number of key/value pairs in the map.
no setterinherited
lock → IMap<K, V>: no setter
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
values → Iterable<V>: The values of this.
no setterinherited

Methods

addAll(Map<K, V> other) → void: Adds all key/value pairs of other to this map.
inherited
addEntries(Iterable<MapEntry<K, V>> newEntries) → void: Adds all key/value pairs of newEntries to this 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: Removes all entries from the map.
override
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
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: Look up the value of key, or add a new entry if it isn't there.
inherited
remove(covariant K key) → V: Removes key and its associated value, if present, from the map.
override
removeWhere(bool test(K key, V value)) → void: Removes all entries of this map that satisfy the given test.
inherited
toString() → String: A string representation of this object.
inherited
update(K key, V update(V value), {V ifAbsent()?}) → V: Updates the value for the provided key.
inherited
updateAll(V update(K key, V value)) → void: Updates all values.
inherited

Operators

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