Prompt augmentation in Powershell

[instinct-vfx]

Hi all,

we are currently switching over to using Powershell as our main shell plugin. While working on this i realized, that prompt augmentation is not happening in Powershell. After a quick check in the code I saw it is simply not implemented. I did take a look and tried quite some things but there is a bit of a conceptual problem.

I am not sure if this is Powershell specific as I am not really familiar with many of the other shells.

It would be trivial to replace the prompt, but not to augment it. The reason is, that the prompt override in Powershell is not a string, but a function and how that function is implemented and where the actual return value is is not known and not easy to figure out if this should allow for arbitrary prompts to be set before running Rez (e.g. something like Powerline Plugins).

I played with this over the weekend and one option is to just copy the whole function and then add the results. That in turn only works once, because with the first nested shell it becomes an infinite self reference. I currently see the following options and would like to get some opinions.

1. Implement as a complete shell replacement dropping any custom prompts that might be set.
2. Implement as "add characters to prompt per nested layer". We need to count up depth of the nesting in en env var and then apply a prompt function that adds a string for every layer. This could also be appended or prepended to the existing prompt from the parent shell.
3. We might also be able to get away with the second implementing a function that is added per layer of nesting.

I might also be missing other options so feel free to chime in. I am generally not really very happy with the way this is currently set up, and configuration being split amongst main config and plugin config. But that is a separate discussion i guess.

Thoughts?

Adding a bunch of people i know use windows to get opinions. Please everyone chime in if you have an opinion.
@nerdvegas @JeanChristopheMorinPerso @davidlatwe @bfloch