Feature request: show current line execution indicator in notebook cells (similar to Google Colab)

[flacle]

Description

In Google Colab, a moving indicator (green triangle) highlights which line of code in a notebook cell is currently being executed. This can be useful for visually tracking long-running code and understanding where time is spent during cell execution.

Benefits:

• Visual feedback: Clearly shows progress through lines of code as the cell runs.
• Profiling: Helps identify slow lines in real-time, especially for lengthy cells.

Suggested solution

Ideally:

• The highlight/arrow/marker should move down as execution progresses.
• Optionally, allow disabling/enabling this in settings.

Reference:

This enhancement would help with debugging and provide useful insights during cell execution.

Are you willing to submit a PR?

• Yes

Alternatives

Alternative solutions include displaying the line of code currently being executed in a dedicated spot, assuming that having a moving indicator adds complication overhead.

Additional context

This request is inspired by Google Colab and would be useful for profiling and debugging long-running notebook cells.

[flacle]

The VS Code Jupyter repo has a similar request: microsoft/vscode-jupyter#16236