New REPL and readline's vi editing-mode

[tmontes]

Bug report

Bug description:

Hi Python devs,

Trying out the new 3.13 REPL(love the improvement!) I faced a behaviour bump on my setup: I configure readline to be in vi editing mode, having a single set editing-mode vi line on my ~/.inputrc -- I'm running macOS 12.7.4 but the same behaviour is observed on Linux.

Observed behaviour:

1. Launch python REPL with python.
2. Prompt is coloured, as expected.
3. Type in import sys.
4. Hit ESC then k -- the equivalent of "give me the previous line".
5. Nothing happens.
6. Hit the up arrow, instead.
7. This time the previous line, import sys, is restored.

Expected behaviour -- hitting ESC then k should restore the previous line and, in general, hitting ESC should go into "vi command mode" (not sure how this will work with multi-line history entries, but that is yet to be explored).

However:

• When running with PYTHON_BASIC_REPL=1 the vi mode line editing works.

Since I'm running macOS and it does not ship readline, I figured I needed a better diagnostic (not sure if www.python.org's macOS Python bundles it -- it seems so, but I digged deeper).
On a Rocky Linux 9 host:

• Cloned the git repo.
• Checked out the 3.13 branch.
• Installed all lib dependencies including readline-devel.
• Built commit c4b853f2a5a4601806f503f1833dce3a4e8d2b58:

  $ ./configure --with-pydebug
  $ make -s -j2
  

• The resulting ./python executable shows the same behaviour -- readline's vi editing mode does not seem to be respected.

I did not look deeper into the code but I will be glad to assist in the diagnostic/fixing of this -- hoping that going forward, with a more powerful REPL, I can still leverage my finger memory from years of using vi.

Thanks again.

CPython versions tested on:

3.13

Operating systems tested on:

Linux, macOS

[ambv]

The new REPL will not be implementing inputrc support, and consequently there won't be a vi editing mode. Use PYTHON_BASIC_REPL for that, this is not going away.