generics

func AssociateBy[A ~[]X, X any, Y comparable](input A, assocBy func(X) Y) map[Y]X

func MapList[A ~[]X, X, Y any](input A, mapper func(X) Y) []Y

func MapMap[X ~map[A]B, Y ~map[A]C, A comparable, B, C any](input X, mapper func(A, B) C) Y