Ark: Issues with incomplete inputs in Jupyter apps

[lionel-]

When an incomplete prompt is detected and R needs more input, we reply with a ExecuteResponse::ReplyException. This should never be the case in Positron since we only send complete inputs, but this error is seen in Jupyter apps. There are currently a couple of issues:

• We see a weird syntax error caused by the way we wrap inputs in braces to avoid printing intermediate expressions (ignore the INFO message):

• Once we fix this syntax error I'm pretty sure Ark will be in an unexpected state because we don't reset the REPL state and R is still waiting for more input to complete the current command. To fix this, we could try running invokeRestart("abort") (I'd rather not send an interrupt).

[DavisVaughan]

I do see that incomplete is also an error on the python side