For and Range components (loop/iterators)

[emil14]

Range (from, to int) SubStream<int>
For (to int) SubStream<int>

These components took numbers as inputs and produces sequences (substreams) of numbers on the out. E.g. for for every to on the input produces 1, ... N on the outport. E.g. For(5) -> (0 1 2 3 4) ->. Same for range except it possible to start from something that is not zero.

Also range could probably work in the opposite direction like range(5, 2) -> (5, 4, 3, 2) ->. There are some questions BTW

Problems

1. Should to be inclusive or exclusive like in e.g. Python?
2. Should we have something like this for "iterables" (arrays/vectors/maps?)
3. Do we want while?
4. Other loop forms?
5. How does it matches with "normal" FBP loop?