Group<E> class
A namespace for functions that group an Iterable's elements.
To access Group, call the GroupableIterable.group extension getter on an iterable.
These functions are intended for 1:N mappings. See Iterables.associate for associating one element by one key (1:1).
Example
final iterable = [('a', 1), ('a', 2), ('b', 3)];
final aggregate = iterable.group.lists(by: (e) => e.$1);
print(aggregate); // {'a': [('a', 1), ('a', 2)], 'b': [('b', 3)]}
Properties
- hashCode → int
-
The hash code for this object.
no setterinherited
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
Methods
-
by<
K, V> (Select< E, K> by, {required V as(V? previous, E current)}) → Map<K, V> -
Groups the iterable's elements by keys returned by
bybefore being folded usingas. -
lists<
K> ({required Select< E, K> by}) → Map<K, List< E> > -
Groups the iterable's elements in lists by keys returned by
by. -
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
sets<
K> ({required Select< E, K> by}) → Map<K, Set< E> > -
Groups the iterable's elements in sets by keys returned by
by. -
toString(
) → String -
A string representation of this object.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited