Lambda it2 - split?

[Janda Martin]

Hi,

  I have newbie question. Does lambda streams support some kind of split operation?

Virtual problem:

Input: collection of cities
  List<City> cityList

Output: average age for all people
  double avgAge

Steps to solve:
  1) Each city MAP to collection of people
  2) Compute AVG over collection of people

I know that I can 
- MAP input value exactly to another value
- REDUCE collection to one value

But can I?
- SPLIT input value into 'stream' (not collection) of another values
  

Thank you very much for answer

  Martin

PS Sorry for my bad English. I hope that you understand what I mean.