Unexpected behavior when reordering cells

[ryanlovett]

When I reordered the first two cells in notebook via drag-n-drop:

I expected to see an exception that a was undefined. I also thought the cell execution numbering (i.e. [N]) would get reset.

[ellisonbg]

A key point is that the graph of cells that determines their dependencies is maintained in the kernel and is independent of the spatial ordering of the cells. This was one of the pain points (order dependence of cells) of the normal IPython kernel that this kernel is trying to tackle. Put another way - we consider it a key feature that users can re-order their cells without worrying about what gets run when. An outstanding question is how to manage this when a kernel is just started and cells haven't been run (what is the right initial run order?).

…

On Wed, Dec 19, 2018 at 12:16 PM Ryan Lovett ***@***.***> wrote: When I reordered the first two cells in notebook via drag-n-drop: [image: screen shot 2018-12-18 at 3 19 20 pm] <https://user-images.githubusercontent.com/10248125/50245439-4edbb280-0387-11e9-8a42-d92f7f1b6108.png> I expected to see an exception that a was undefined. I also thought the cell execution numbering (i.e. [N]) would get reset. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#34>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AABr0G30kVi8Ft1FzHL4qKmGLXbEQRI_ks5u6p6sgaJpZM4Za9Fz> .

-- Brian E. Granger Associate Professor of Physics and Data Science Cal Poly State University, San Luis Obispo @ellisonbg on Twitter and GitHub bgranger@calpoly.edu and ellisonbg@gmail.com

[dldx]

Does it help to look at how Observable does it? https://beta.observablehq.com/@mbostock/how-observable-runs