Potential for integration with PSReadLine's `ViEditVisually` function

[mklement0]

I think Show-PSEditor has great potential for integration with PSReadLine's ViEditVisually function; the latter allows invocation of an editor as a richer alternative to direct command-line editing, and Show-PSEditor's features make it ideally suited to that.

However, for this to be possible:

• PSReadLine would have to be enhanced to allow specifying a PowerShell command via $env:VISUAL or $env:EDITOR - currently, only an external program may be specified.

• Show-PSEditor's current behavior too could be enhanced to support that:

  • Notably, addressing #52 would help (as well as #50).
  • Ideally, there'd also be a way to pass the startup cursor position, so as to place the cursor in the editor buffer in the same position it was in the command-line buffer, as supported by code and micro, for instance (expressed in terms of the target line and column number).
    • That said, PSReadLine would either have to be enhanced to somehow communicate this position to the ViEditVisually function; however, a custom implementation of said function can enable such functionality already (see below).

---

See https://github.com/PowerShell/PowerShell/issues/21525#issuecomment-2078215370 for a proof-of-concept that allows you to set $env:VISUAL or $env:EDITOR to 'psedit' or 'Show-PSEditor' to experiment with what such an integration could look like.