About implementing specific custom primitives

[breakds]

Sorry about using GitHub issues for asking questions again. After switching to cpp20 branch I was able to successfully run examples. Thanks!

Now I would like to discuss on whether (and how) the following can be achieved. The dataset that I having is actually a time series which is ordered. This means that theoretically primitives such as "shift 1" and "shift -1" or "rolling mean" are valid primitives that can batch operate on each of the original variables and intermediate variables. After briefly reading the code, mainly functions.hpp, I have a few questions on how to implement the above:

1. It seems that there is an upper limit on the number of primitives we can have because NodeType is 32 bit integer. If I would like to add more primitives, should I extend this to uint64_t?
2. It seems that each time when the primitive in function.cpp is called, it is called on a batch of a variable or intermediate. Is it possible to make it call across the whole dataset (across the data point dimension, which in the time series case is the time dimension)?
3. If the above two can be resolved, I think I can probably come up with a solution. Is there any other approach that you would recommend?

Thank you!