Feature Request: Shell Widget

[knpwrs]

FZF and Navi have the concept of shell widgets, they can take over your prompt and then when you're done leave you with the text you wanted filled-in to your prompt.

I think Navi's shell widget is a good example of what I'm talking about (see navi widget zsh, for instance). You can press ctrl-g, fill in a template, and when you're done your prompt is pre-populated with the command you selected and filled in. If you already have stuff filled in when you press ctrl-g then Navi takes that into account and starts a search for you.

It would be cool to, for instance, press ctrl-u with some command already filled in and have up take over at that point. Once done, exiting up would leave the prompt pre-filled with the final pipeline.