Implement "operate-and-get-next (C-o)"

[mgalgs]

One useful feature in bash is to go back in history, find a command you want to execute, and execute it, loading the next command. This is useful for repeating sequences of related commands that are often repeated together. It's bound to C-o in bash and zsh (and probably others).

You can see how it works in bash by running:

$ echo "going to tmp"
$ cd /tmp
$ echo "hello, world"

then hit C-p C-p C-p C-o C-o C-o (for a grand total of 6 keystrokes) to run those same three commands again.

Here's the description from BASH(1):

     operate-and-get-next (C-o)
          Accept  the current  line for  execution and  fetch the
          next line relative to the current line from the history
          for editing.  Any argument is ignored.

[jonathanslenders]

Very useful feature! Thanks for the request. I'll see how we can implement this.

[jonathanslenders]

Hi @mgalgs,

This has been implemented in 719b94c .
You can use this example for testing: https://github.com/jonathanslenders/python-prompt-toolkit/blob/master/examples/operate-and-get-next.py

However, right now, it doesn't work in most prompt_toolkit applications yet. The reason for that is that I don't do a good job of keeping the state between consecutive calls of the "prompt()" function. We don't automatically carry the history to the next call, but even if a user does that explicitely, that's not sufficient for this to work. For IPython it works, if they remove the custom binding for Control-O that they have. I'm also planning to make this work for ptpython (where it doesn't work because the flow is different from other applications). I need to fix that.

So, my plan is to rewrite the "prompt_toolkit.shortcuts" module, and create a better API for readline-like applications, that correctly transfers state between multiple prompt-calls. (See #440 ). Then, when this is ready, everyone should start migrating to this API in order to get this functionality.

[jonathanslenders]

Closing this, given that it's implemented. Feel free to open again, if something is missing.

[mgalgs]

For IPython it works, if they remove the custom binding for Control-O that they have.

For any future searchers, here's how you can remove IPython's Control-O handler so that you can get this Control-O goodness:

~/.ipython/profile_default/startup/20-keyboard.py:

from IPython import get_ipython
from IPython.terminal.shortcuts import newline_with_copy_margin


ip = get_ipython()
registry = ip.pt_cli.application.key_bindings_registry

registry.remove_binding(newline_with_copy_margin)

[randy3k]

@mgalgs
excellent tips!!

[randy3k]

By the way, in iPython 6, I need

from IPython import get_ipython

ip = get_ipython()
registry = ip.pt_cli.application.key_bindings_registry

handler = next(kb.handler for kb in registry.key_bindings if kb.handler.__name__ == "newline_autoindent")
registry.remove_binding(handler)

[mgalgs]

One more iteration on @randy3k's solution (which I needed to get things working in both python2 and python3):

from IPython import get_ipython

ip = get_ipython()
registry = ip.pt_cli.application.key_bindings_registry

handler = next(kb.handler for kb in registry.key_bindings
               if kb.handler.__name__ in {"newline_autoindent",
                                          "newline_with_copy_margin"})
registry.remove_binding(handler)