groupBy
inline fun <E : Any, K> EntitySequence<E, *>.groupBy(keySelector: (E) -> K): Map<K, List<E>>(source)
Group elements of the original sequence by the key returned by the given keySelector function applied to each element and return a map where each group key is associated with a list of corresponding elements.
The returned map preserves the entry iteration order of the keys produced from the original sequence.
The operation is terminal.
inline fun <E : Any, K, V> EntitySequence<E, *>.groupBy(keySelector: (E) -> K, valueTransform: (E) -> V): Map<K, List<V>>(source)
Group values returned by the valueTransform function applied to each element of the original sequence by the key returned by the given keySelector function applied to the element and returns a map where each group key is associated with a list of corresponding values.
The returned map preserves the entry iteration order of the keys produced from the original sequence.
The operation is terminal.
