Allow language extensions to expose a persistent interactive console (REPL)

[daviwil]

While it is awesome that we have the Debug Console for an interactive console experience while debugging, it would be ideal if VS Code also supported a persistent REPL (interactive console) which could also be used at any time. Users of languages such as PowerShell, F#, Python, Ruby, and many others would benefit from this.

At least in the case of PowerShell, all that would really be needed is an event that can be registered when the user enters a command and then some API for writing the output. The PowerShell, F#, and Elm extensions already simulate this by allowing the user to select some text, run a command to execute it, and then have the output written to an output channel.

Users of the PowerShell extension have requested feature this here: PowerShell/vscode-powershell#10

cc @Krzysztof-Cieslak

[Krzysztof-Cieslak]

General 👍 to feature. Would be really cool to get such feature (especially when Debugging Console practically implements everything we would need)

For sure it would be useful for many languages (nowadays even C# has REPL ;) ). As David said, in F# and Elm we just allows user to send line / selection / file to REPL and we print output to Output Channel - that's how it looks more or less:

While for F# it's my decision to have such style REPL (we've implemented exactly same functionality [read-only REPL window] in Atom even though we could get more traditional style) other languages and their communities prefers to use REPL by just typing code into it and plugins supporting those languages would really benefit from adding this.

[Krzysztof-Cieslak]

cc: @mat-mcloughlin for Elixir plugin.

[mat-mcloughlin]

+1 on this feature

[RobCannon]

+1 on this feature. Also, I would like to see an option to see the REPL window on the bottom.

[egamma]

I would like to see an option to see the REPL window on the bottom

agreed and this is on our backlog.

[wjdavis5]

+1 want to run some npm, or nuget or stuff directly from vs code.