Returns a new lazy Iterable with elements that are created by
calling f on each element of this Iterable in iteration order.
This method returns a view of the mapped elements. As long as the
returned Iterable is not iterated over, the supplied function f will
not be invoked. The transformed elements will not be cached. Iterating
multiple times over the returned Iterable will invoke the supplied
function f multiple times on the same element.
Methods on the returned iterable are allowed to omit calling f
on any element where the result isn't needed.
For example, elementAt may call f only once.
Source
Iterable<T> map<T>(T f(E e)) => new MappedIterable<E, T>(this, f);