SegArray.__getitem__ to Server

[Ethan-DeBandi99]

Part of #1682

Update SegArray.__getitem__() so that SegArray indexing is done server-side.

Note: There is a good bit of the structure all ready in place for this from SegString. We should be able to reuse this functionality.

[Ethan-DeBandi99]

@reuster986 - I just ran across something that I wanted to get your take on. Initially, when I moved SegArray over to the server, I did not update the __init__ because I was worried it may interrupt user workflows. However, as I am moving functionality over it appears we will need to go to something in line with Strings in adding a class method from_parts with identical parameters to the existing SegArray.__init__ and then we could update the __init__ to build from the st.attrib call response method. I have a way to work around this, but it generates the SegArray on the server twice which I am not a fan of. What are your thoughts on update to a from_parts method to support the current constructor functionality?

[reuster986]

I'm not sure I understand all the pieces of this puzzle, but I think imitating the Strings implementation makes sense, since Strings are basically a special case of SegArray to begin with. In your proposal, would the user still be able to write sa = ak.SegArray(segs, vals) in Python? In other words, would the user ever need to call from_parts?

[Ethan-DeBandi99]

The user would need to call ak.SegArray.from_parts(segs, vals). Strings doesn't do this because you can essentially just call ak.array(). The __init__ for strings builds of the return from the message. I just did a quick outline to verify, but the only things that updates is having to call from_parts. We could add a top level function that could be called like ak.array, something like ak.segarray(segs, vals) that would call from_parts behind the scenes.