I’m trying to solve aoc day 3 and my idea is to generate list of points
[“R2”,“U3”]
starting from the point {0,0} then 2 points Right and 3 points Up
the results needs to be:

[
    [{1,0},{2,0}],
    [{2,1},{2,2}{2,3}]
]

or as a drawing:

..u..
..u..
..u..
orr..

my implementation is that I map over the first list,
inside I pattern match on the direction and create a range with the length of vector then again I map over the range to generate the points.
The problem is that every nested map needs a different starting point (the last point from previous list) and I’m not really sure how to pass this variable in elixir - I’m thinking about a global variable but there is probably an easier solution

PS. I don’t want to ask in the aoc thread due to spoilers and I think the problem is more generic

Solution: the longer I think about it I need Enum.reduce instead of map and accumulate the new list in accumulator - this way I will have access to it in the next iteration