ENH: split cell at cursor

[westurner]

Is your feature request related to a problem? Please describe.

STORY: Users can split the current cell at the current cursor position, in order to refactor into more notebook cells.

Describe the solution you'd like

• ENH: Create a keyboard shortcut for splitting the current cell at the cursor
  • ENH: cell IDs change upon copying, pasting, splitting
    • DOC: JEP #
  • UBY: decide on a keyboard shortcut
    • e.g. JupyterLab has 'Ctrl-Shift-Minus',
      which is going to be muscle memory for people coming from that tool,
      so maybe Ctrl-Shfit-Minus for jlab compatibility, and, though:
    • 'Ctrl-Shift-Minus' collides with (is it Global or Local) font size decrease on Chromebooks, so there needs to be another keyboard shortcut to split cell
      • ENH,UBY: jlab: that should/could be added back to jlab, too

Describe alternatives you've considered
Copy and paste to a new cell, instead of splitting at cursor:

• Shift + PageDown # PageDown = Fn + Down arrow # Select all
• Ctrl-X # Cut the rest of the cell
• Create a new cell in colab
• Ctrl-V # Paste the rest of the previous cell

Additional context

• https://jupyter.org/enhancement-proposals/62-cell-id/cell-id.html#questions ::

  • How is splitting cells handled?
    • One cell (second part of the split) gets a new cell ID.

• Support cell IDs jupyter/nbdime#553

[craigcitro]

Note that this already works: ctrl-m - (ctrl-m followed by -) will split the current cell.

[westurner]

• Colab: Add split cell to command palette, menus

Why does it only work in emacs pinky mode?