List.GetItemAtIndex should work with negative indices.

[JacobSmall]

What improvement/feature would you like to see in Dynamo?

Negative indicies less than the length of the index should pull from the end of the list.

How would you see this improvement/feature working?

this would return the last item in the list.

[andydandy74]

@Amoursol @JacobSmall Just noticed the PR for this issue. Have the repercussions on existing graphs been considered? The GetItemAtIndex node is often used in conjunction with the IndexOf node. Currently that node will return -1 for items not found in the list. So what I envision happening in existing graphs is that instead of returning null for items not in the list we will now see the last item in the list returned in such cases:

Would it perhaps make sense to have the IndexOf node return null instead of -1 for items not found in the list in the future?

[QilongTang]

@andydandy74 You are right on the expected result

@Amoursol I think the proposed change on IndexOf node makes more sense after the negative index support, what do you think?

[andydandy74]

Proposed change see DynamoDS/Dynamo#15268

[Amoursol]

@QilongTang Returning null works for me!

[mjkkirschner]

@QilongTang @avidit - perhaps it's worth taking a sec to consider other approaches like adding a new node with this behavior.
We know that returning null and passing it downstream creates its own issues.
Additionally it seems like we're missing some test cases that combine using the two nodes.