Well, It looks interesting, what exactly does it d...

# rx

[gabrielfv]

Well, It looks interesting, what exactly does it do?

[alex.hart]

Scan method functions as documented here: http://reactivex.io/documentation/operators/scan.html

My implementation is one which simply doesn’t rely on Rx:

1. I have a list of stuff [1, 2, 3, 4, 5]
2. If the list is empty, I simply return it.
3. Otherwise, we fold over the tail of the list, using a singleton list containing the first item as our start object. Each iteration of fn returns a list with all of acc plus the result of the latest object in acc, and the item, applied to fn.

In the case of [1, 2, 3, 4, 5], fn = {x, y -> x + y}:

We fold over: [1], [2, 3, 4, 5]
Iter 1: acc = [1], item = 2, fn(acc.last(), item) = 3
Iter 2: acc = [1, 3] item = 3, fn(acc.last(), item) = 6
Iter 3: acc = [1, 3, 6] item = 4, fn(acc.last(), item) = 10
Iter 4: acc = [1, 3, 6, 10] item = 5, fn(acc.last(), item) = 15
result = [1, 3, 6, 10, 15]

[gabrielfv]

I see, interesting

[gabrielfv]

Thanks for the explanation